# Pm1340gt Lathe Basic Vfd Control Conversion Using The Stock Control Board And Switches



## mksj

Many individuals buy the PM1340GT lathe as a 3 phase machine with the intent to convert it over to a VFD system, the usual VFD that is used is the Hitachi WJ200-015SF. Unfortunately the conversion often requires a somewhat complex and costly conversion process to optimize many of the VFD functions.  In many cases the machines may sit for many months if one is not familiar with how to do the conversion. I normally do these builds/conversions for other individuals, and have shared this information in this forum, but it is somewhat involved and very time consuming.

I normally do not recommend using contactors as relays for low level signals used to activate the VFD inputs, but if a machine is new and the contacts are not burnt, it is possible to rewire the stock control board (strip out the high voltage wiring and oveload relay), and use the contactors to switch the Forward/Reverse inputs contacts on the VFD. Once rewired, the machine will function the same as the stock machine would, and it will have the benefits of slower acceleration, faster deceleration and speed control.  A VFD Jog can be incorporated by using a dual switch block Jog switch.

The stock 3 phase (or single phase control board with a 3 phase motor replacement) PM1340GT system control board and switches are reconfigured so that the contactors are used to activate the VFD control inputs for forward and reverse, the JOG button on the front panel activates the forward contactor which will work exactly as the non-VFD configuration, i.e. the motor will jog at the same speed as the forward command would. The conversion is best made by removing the control cable wires from the control system terminal and removing the control board from the machine. This should only be attempted by individuals that are comfortable with rewiring systems, and want to get the machine into an operational state. The attached documents provides the recommend procedures, although I have converted the stock  PM1340GT control board to operate as such but have not done this as a complete conversion, *so you can try it at your own risk*. Please check all your connections, if you do not understand or cannot test the system, then have a system built for you and have an electrician work with the high voltage wiring. A basic overview of the changes are in the attached document.

Stock PM1340GT system control board






Modified PM1340GT control board with high voltage and motor connections removed. It retains the the stock 24VAC transformer and the controls work in the same manner as then non-modified board.





Full PM1340GT VFD Control Board System


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## Firestopper

Nice write up Mark. Many will benefit from this and as always, very clean work.


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## arvidj

Nice write up.

Maybe someone can provide a reference to information I've not been able to locate. I am wanting to put braking resistors on several WJ200 VFD's. It easy to determine the minimum resistance ... just look in the manual and see it is 35 or 50 ohms depending on the 2.2kw or the 1.5kw converter and 10% usage, respectively. What I have not been able to find documented is how to determine the wattage.

I understand the purpose of the resistor is to convert the braking energy to heat and wattage is an indication of the amount of heat\energy the resistor can safely dissipated without bad things happening. And I understand that "too much wattage" is not a technical problem but it does present other issues such as space and costs that do come into play.

Obviously the calculation would need to take into account what I was trying to stop. Just a spindle would not have nearly as much kinetic energy as the spindle with a large three jaw chuck and a large piece of metal in it. But setting that discussion aside for the moment, I've not been able to find any suggestions as to the wattage calculation.

Maybe I should just say the heck with it and get several of the fancy 500 watt shiny aluminum finned models from eBay at ~$40 each ... or just cheap out and get a 220 volt 1500 watt water heater element ... about 35 ohms ... at ~$9 a pop from the big box store.

Arvid


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## mksj

Hi Arvid,

The braking resistor is dependent on the WJ200 VFD model, voltage, phase and application. The attached file provides the specifics on the recommended braking resistors for the WJ200. The dissipation is application specific, so in cases where the VFD needs to hold a load in a static position, used with high frequency, etc. then the maximum wattage would be appropriate. In a lathe or mill, they brake for a few seconds and the dissipation is much less. I use a 500W 50 Ohm resistor on the WJ200-15SF for the lathe it doesn't get past slightly warm with repeated use and 1 second braking. You also need to think about mounting space and the lead voltage, which on a 220V VF, the braking resistor leads can go up to 400V.  As far as resistance range, probably -10 to +50% of the specified value would be acceptable, so something like a 47 Ohm resistor should be fine for a 50 Ohm specification, and 75 Ohm for the high end value. The flat aluminum encased resistors will take up much less space, but need to be mounted to a metal surface to achieve their dissipation rating. In free air, a 500W resistor would be derated to something like 100-200W, and even then it would be fine in this application.

So for the WJ200-15SF I would suggest a 50 Ohm 250-500W resistor, the WJ200-22SF I would suggest a 35 Ohm 300-500W resistor. These are usually available on eBay for a little over $20, they are easy to install and take up much less space then the open air coil types. 

Mark


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## JimFouch

I have a new PM-1340GT on order with Matt. 

I'm planning on doing this upgrade. Will this work?


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## mksj

Yes. This will also work, cost $17.10. http://www.ebay.com/itm/300W-50-ohm...ed-Braking-Resistor-5-Tolerance-/171807049857


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## GA Gyro

mksj said:


> Yes. This will also work, cost $17.10. http://www.ebay.com/itm/300W-50-ohm...ed-Braking-Resistor-5-Tolerance-/171807049857



That is the one I purchased... easy to mount.

Wires are a little short, however with a little creative thinking, worked out mounting it on the cabinet for cooling.


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## JimFouch

I ended up ordering a 500W one from eBay. Now it will be a race to see if it gets here before my new 1340GT.....


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## arvidj

Mark,

Thanks very much. That is 'the chart(s)' I have been looking for but have never been able to find!!

Arvid


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## JimFouch

So with my PM1340GT on it's way to Matt in Pittsburgh, I'm starting to get some things in place so when I pick it up 2nd or 3rd week in August, I have some parts already to go on it.

Seeing this talk of upgrading the 3PH motor from stock I took a gamble and bought one of the E467 talked about on another thread. I think I got a pretty decent deal. It's NOS. Got it for $226 shipped. I think there are some suppliers selling them for like $385+shipping.

I know there are a ton of features that can be programmed on the WJ200 to control how it run/stop the motor. Is there a way for it to be programmed to stop the chuck in the same spot each time? I'm guessing no. There was some talk of an encoder on the motor shaft to control speed, but even if that were possible, you would never know how that relates to the chuck position because of all the different gear ratios.

I'm wondering if it would be possible to place a magnet on the chuck and have a microcontroller jog the motor until it has reached a hall-effect sensor and the desired stop point. This will allow the chuck key to always be accessible. I know it would be some extra electronics, but nothing I couldn't figure out.

I'm already planning on using the input from the hall-effect sensor for an RPM display I have planned.

I'm new to working with a lathe, but having to rotate the chuck to find the key most every time I stop seems to be an inefficiency that could be resolved. 

I love hacking machines and making them better.....


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## mksj

JimFouch said:


> I'm new to working with a lathe, but having to rotate the chuck to find the key most every time I stop seems to be an inefficiency that could be resolved.


Most chucks have either 2 or 3 key chuck pinions, so really not an issue. The chuck rotates easily or bump with the jog. Probably one of the most common requests I get for VFD control systems is for a Joystick Jog, so a very quick way to bump the chuck or turning to a specific spot. A proximity sensor stop used with a VFD will give you pretty much the same exact stopping/chuck position if threading and not disengaging the half nut.
http://www.hobby-machinist.com/thre...ding-with-a-proximity-stop.45977/#post-391715

The Marathon E467 should work very well and give a little better motor control, but the stock PM1340GT 3 phase motor is very good also. That is a very good price on the one your purchased. The E467 (and stock motor) should easily max out at 90Hz maintaining full Hp. Although Torque drops off above the motor's base frequency, the torque at the spindle would be the same as a 60Hz motor when you take into account the mechanical gearing ratio.
Mark


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## qualitymachinetools

Great information as always mksj!!!!!!!


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## chocadile

I just want to say thank you to Mark for making this information available.  I have this exact machine PM-1340GT and WJ200 VFD and after reading trough the manual I feel much more comfortable tackling this project.  I will post back and let you know how it's going.


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## chocadile

I do have one question for Mark or anyone else who has performed this install.  I am up to the point where I am installing the transformer wires onto the terminal block.  I wanted to be sure of the orientation of those two wires " S, and R ."  In Marks write up he doesn't specify and it's really tough to see the routing of those two in particular.  Everything so up to this point has been a breeze.  Hopefully the rest of this project will go the same way.










edited to show images of cleaned up board ready to go back onto the machine.


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## mksj

There is no orientation to the S and R, since it is 220/240V which is split phase. The wire routing is not critical, I pulled the wires forward and connected them to terminals 1 and 2, so you would need to bring in power 240VAC to the board, You also need to ground the transformer (green terminal) and the control box the same as the stock system.


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## chocadile

Thank you for the response Mark.  I have left the stock transformer ground as is.  Green wire from the green terminal to the side of the transformer on a stud.  Do I  need to run and additional wire from the green terminal to the ground on the control box?


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## mksj

Yes, the control board is phenolic so there is no ground connection from the transformer to the control box. You want to also ground the control box since there is 240VAC coming into it. This assures a good local ground, even though the motor is also grounded. All the grounds should go back to a single point (star ground), such as a metal back plane that the VFD would be mounted to, otherwise you can use a stud mounted where the power comes into the machine.


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## chocadile

Mark you've been a great help and it is very much appreciated.  I ran the additional ground from the transformer to the control box as you suggested.  I think I've run into a problem though.

  Like many others this machine sat in the shop for 3 to 4 months before I started this project yesterday.  I'm having to deal with existing wiring that I'm not 100% sure is correct.  I'm a complete newbie with this and want to be sure things are correct before turning the power back on.  Please forgive me if my questions seem very basic.

Here is my problem (I think haha), I'm ready to bring power to the board but it looks like we only have one 208V 3 phase cable coming into the room.




this is the existing wiring I spoke of previously.  It looks like the electrician ran the power to the VFD, and them from the VFD to the control board.  Here are the connections he made.




From my very limited understanding, this seems incorrect.  I believe I need to have two power sources, one for the control board and the other for the VFD.  It looks like the area where I need to wire my motor into is being used by the power cord the electrician set up to go to the control board.  

This is where I'm at now box and control board mounted to the lathe, and awaiting power to the terminal block.





Please let me know if my assumption is correct/incorrect, and what further steps I need to take.


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## tmarks11

Was your machine shipped to you as a 3 phase machine?  

Most aren't, most of them operate off of 240V, single phase.


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## chocadile

tmarks11 said:


> Was your machine shipped to you as a 3 phase machine?
> 
> Most aren't, most of them operate off of 240V, single phase.



Yes I believe it was Tim.  I'm out of the shop for the night so can't go physically check right now.  I am fairly certain it is a 3 phase motor.  I'll reaffirm tomorrow.


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## mksj

The ground is wired fine, on the connections to the VFD it is difficult to see from the picture. If this is a single phase VFD (WJ200-015SF), then power (240VAC) comes in and connects to the input power L1 and N, the motor connections are U/T1, V/T2 and W/T3. The power transformer power would connect to L1 and N terminals, or the main power system switch.  Nothing but the motor should be connected to the motor output terminals of the VFD. I am assuming you have a 3 phase motor, it makes no difference for the contactors/transformers if this was a single phase or 3 phase version.


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## chocadile

I tried to get a clearer picture of my connections to the VFD, I can take more if need be.




My VFD is version WJ200 - 022LF




and thank you for the explanation and diagram that makes things clearer for me.  I hoping that the model of my VFD won't change the details of this install to much.  I apologize for not just giving all info upfront but, I've been kinda peicing this together as I went along.  I am very greatful that you all are to to help out.


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## chocadile

Just went and had a look at the motor specs it is a 3 phase and specs are as follows,

HP - 2                     KW - 1.5
Volts - 220              Poles - 4
Hertz - 60               RPM - 1720
Amps - 6.6              Heat - 60 deg. C
Phase - 3                 Date - 2016 01
Class - E                  Ser. - 2805


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## mksj

OK, so this is a 3 phase in VFD, the single phase version is the SF model. On some VFDs, the 3 phase model can be used on single phase, but usually there is a derating of about 0.6 x the nameplate kWA. So a 2.2kW/11A 3 phase would be derated to about 1.4kW/6.6A. So you should be able to use this VFD for the motor you have indicated. Sometimes a choke needs to be installed, but lets not go there for now.   Start out by attaching the single phase input to the input terminals L1 and L3, and see if the VFD works. Sometimes you need to put a jumper from L3 to L2, but I would try to do this without the jumper first. Make sure the power is fused or on a breaker sized for single phase input. This works out to a 20 or 30A breaker, or for fusing ~30A fuse in the power lines going to L1 and L3  depending on the type and style. The VFD needs to be programmed for the motor nameplate information, along with the other parameters, out of the box it has different motor parameters.


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## chocadile

Hi Mark,

I' a little confused or not understanding the terminology but, I only have a 208V 3 phase power coming into the room. When you say attach one phase you mean one of the wires from the 3 phase connection? 

I do know that the current wiring did power the VFD.  I was able to turn it on and run through the parameters.  I initially started by setting the B037 to " 00 " and started setting the parameters for my motor.  

The electrician who installed the VFD has Black going to R/L1 Red going S/L2 and White going to T/L3.  He left the ground Green wire floating (not connected to anything).

Thank you for bearing with me through this.


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## tmarks11

You need to ground your motor and the VFD.  The motor when running can induce a significant voltage level in the motor casing, which will shock you if you touch it. DAMHIKT..


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## mksj

Then it is fine as wired, I was unaware that you had 3 phase available. There would also be no derating for the VFD.  As mentioned,  the ground wire should be connected at both the VFD and the motor, it should not be floating. I normally use shielded motor cable, the shield is only grounded at the VFD end, this is separate to the ground wire. The transformer is only connected to between 2 phases, so something like L1 and L2.


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## chocadile

I was able to make some progress this morning.  I think I'm just about there.  I cleaned up all the connection at the VFD, wired up the motor, and have my grounds wired as well.  

Pics of latest wiring.

Wiring at VFD




	

		
			
		

		
	
   3 phase power into VFD Blk@R\L1, Red@S\L2, Wht.@T\L3.  Also attached at R\L1 and S\L2 are my power wires going to the terminal control board opposite my transformer leads. 




Motors wires are matched accordingly




Grounds are all wired back to the ground location at VFD.  The 2 on the left are from the incoming 3 phase power, and from the motor ground. The one on the right is from the ground on the control board/transformer.  





I have not wired up any of the logic controls yet.

I am ready to flip the breaker back on but would like trained set of eyes to look and see if my wiring looks correct.  I can then turn power back on and get to programming the VFD, and get the logic controls wired up.  Thanks again to all that have come to help me out.  Hope everyone enjoyed their weekend.


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## mksj

Looks good, should be fine to power it up. You can program and auto tune the VFD to the motor via a computer via a USB cable, otherwise do it manually. When auto tuning, the belt needs to be removed from the motor.


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## chocadile

Thank you Mark, I'll let you know how it goes.


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## chocadile

I flipped the switch and success!!! All this work is starting to pay off haha.  I downloaded the driver and software and began the changing of my parameters.  First thing I did was auto tune the motor. I also went through and performed most of the parameter changes indicated in your tutorial.  From the software I am able to run the spindle forward/Reverse and change the Hz to change spindle speed.  When I move the drive lever up and down I can hear the contacts clicking on and off.  I can also hear contact clicking when pressing the jog button.  My light goes on and off with the E-stop.  I feel like I'm nearly there 

  So I believe my next step is to wire up the logic controls and I need a little bit more detail if you have the time.  I can see from the tutorial that wires come from the contacts, 1 from both contacts L1 to P24, and then wires from each contactor T1 go to VFD terminal 1 and 2 respectively.  This is where I start to get lost.  I can't see from the picture where the wire comes from that connects to VFD terminal 3.  Also the wires that connect to VFD terminals ( H, O, and L) where are those originating from?  Also it looks like I need to my my current jumper over one spot from its current location.






What style of connectors are you using for the logic terminal?  I've not seen anything like this before?  Again thank you for the help its greatly appreciated.


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## jbolt

chocadile said:


> What style of connectors are you using for the logic terminal?  I've not seen anything like this before?  Again thank you for the help its greatly appreciated.



Use wire ferrules, same as is on the end of the jumper. The wire/ferrule will push in but to release you need a small flat screw driver to push in the slot above .


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## mksj

The wiring ferrules work very well, I usually use the orange ones and 18-22AWG control wires. You need a crimper for the ferrules. So something like this: http://www.ebay.com/itm/Adjustable-...Tool-800-Connector-Terminal-Kit-/322191937643 . Do not use solid core control wire, in my experience it will fatigue and break with vibration. Alternatively you could also try to use some solder to tin the ends of something like 18AWG wire.

The control wiring is as follows using source logic, and programing the inputs according to their specific action:


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## chocadile

Thanks you guys.  I am getting the tool and connectors on order today.  Can you get me a pic of the control board as well?  I'd like to see where the wires are originating from on the board.


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## mksj

It is shown on page 6 of the instructions. VFD input terminal 3 would be used if you a dual pole (2 contact blocks) jog switch, one NO contact block operates the contactor, the other NO contact block  connects P24 to input 3 when the switch is depressed. So input 3 sets the lower jog frequency if used.


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## chocadile

Hey everyone,

I got my new crimps and crimp tool in late last week.  I just got some time today to get the logic controls wired and everything is working like it's supposed too.  I again want to say thanks to everyone who helped out.  This seemed like a very daunting task for me but, it turned out to be not that difficult.  Mark this wouldn't have been possible without your help and patience.  I'm happy there's a resource like Hobby Machinist for this kind of information.


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## chocadile

Just a quick update and question for you everyone.  Well update for everyone and question for Mark haha.  I've been using my lathe since getting everything hooked up and running.  Here are some battery terminals I machined for a prototype my company is working on.  It's nothing to crazy but, it was nice to finally be able to throw some chips.








My question is about wiring in my coolant pump.  Is it as simple a process as connecting them to the terminal block on the control board and ground in the enclosure?


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## chocadile

So I made an educated guess.  I look at the specs of my pump and since the motor is 220, I decided to connect to the terminal block opposite of the incoming power to the board.  Pump is now working.


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## smk-machine

I have heard of folks upgrading the motors in these to inverter duty motors. My understanding is that this is very important for higher voltage motors and not as important for a gearhead lathe because you aren't operating the motor off of it's design point too much. Can someone share some personal experience with this? Will the stock 3 phase motor work just fine with an inverter? Has anyone detected any too-hot motors while using a VFD? Thanks.


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## JimDawson

smk-machine said:


> I have heard of folks upgrading the motors in these to inverter duty motors. My understanding is that this is very important for higher voltage motors and not as important for a gearhead lathe because you aren't operating the motor off of it's design point too much. Can someone share some personal experience with this? Will the stock 3 phase motor work just fine with an inverter? Has anyone detected any too-hot motors while using a VFD? Thanks.



Welcome aboard!

I have been using VFDs on non-inverter rated motors for years.  I can run my mill from about 10 - 6000 RPM, using a Baldor 3hp motor, and a sensorless vector VFD.  I converted my mill to direct drive last summer, so the only speed adjustment is the VFD and Hi/Lo gear.  At low speeds, the idle current is about 57% then it drops off to 24% as the speed is increased to about 1800 RPM, at about 3500 RPM the current draw is back up to about 40%.  The motor temperature rise is generally just a few degrees above ambient.  Before the conversion, I normally limited the Hz range from 30 to 90 Hz.  I ran my other mill, with an import motor between 30 and 120 Hz for about 10 years with no problems.


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## smk-machine

Thank you kindly for the welcome. This is a great forum!


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## mksj

Just to add what Jim mentioned, most newer 3 phase motors operate just fine on VFDs, and they are often operated beyond/below what is known as their base speed (usually 60Hz). The issue is the voltage switching spikes because the VFD creates a pseudo sine wave out of many little segments of the voltage being switched on and off. This causes some voltage overshoot in the motor cable and the motor windings. The breakdown of the insulation becomes more of an issue with higher voltage motors. Given that most of the 3 phase motors in our application are rate as 230/460V, and you use the lower volt setting, voltage wise you are running the motor very conservatively and very unlikely to see an insulation breakdown issue. This is a very nice technical description by ABB "Effects of AC Drives on Motor Insulation".  https://library.e.abb.com/public/fec1a7b62d273351c12571b60056a0fd/voltstress.pdf

The other issue is one of cooling the motor at operating points above and below its designed operating speed. Most standard 3 Phase motors use a fan attached to the motor shaft to pull air over the motor known as Totally Enclosed Fan Cooled (TEFC), as such the efficiency/cooling can be an issue at low and high speeds. In general, they do just fine over a range of approximately 30-90Hz, but this is also load dependent. Inverter/Vector motors are usually Totally Enclosed Non Ventilated (TENV) or use an Electric Blower (TEBC). These type of motors have a much wider operating RPM range (usually about 10 fold on smaller motors) and higher short term overload capabilities. On mills and lathes, you will often see 2 mechanical speeds and the VFD covers the wider speed range. The motors are often oversized, to account for the Hp decrease when operating below their base speed. The insulation on inverter motors is usually rated for higher voltages and temperatures to insure longevity under continuous use at high loads, they also have a rated maximum speed of around 5000 RPM for a base speed motor of 1750 RPM.

On my mill the inverter TEBC motor operating range is 20-200Hz direct drive or with a 10:1 reduction gear. On my PM1340GT lathe I routinely operated the stock motor from 30-90 Hz and never had an issue with it's performance of cooling. I did switch it out to an inverter motor to give me a wider operating speed range so I would not need to do a belt change. The motor operates from 20-120Hz with the inverter overload at 180% for up to 1 minute. Running the VFD in sensorless vector mode, the RPM does not change with load.


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## bench

Hello Everybody,

I am learning lathe for hobby. I recently bought a Taiwanese lathe, LD-1216GH, which is basically identical to PM1340GT except for the bed size. Thanks to Mark(mksj) I converted it to run on a VFD (Hitachi WJ200) using the schemes described in this thread. Many thanks to Mark. One thing a bit different is that I added a DPDT mometary toggle switch to have the JOG function in both forward and reverse direction.  Following pictures show how I wired the toggle switch. A DPDT switch has two columns of connectors and on the left column I wired p24 of the VFD to the center connector and input 3 to the top and bottom connectors. On the right column the center connector is connected to terminal 3 in the control box, and the top and bottom ones to the terminal 4 and 5, which activate the forward and reverse contacts, respectively. Now I need to add a proximity switch for carriage stop. Wish Mark would provide a scheme for it.


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## mksj

There are a number of ways to implement the Jog feature, but the basic VFD control conversion is designed to use the stock wiring and allow the use of a VFD to replicate the regular machine controls while adding the variable speed and programmed acceleration/deceleration of the VFD.  It is a very simple conversion. The use of a proximity sensor that I use requires a DC control system (the stock PM1340GT is 24VAC), and involves a number of additional controls and safety interlocks to prevent the machine restart. My recommendation would be to go to a single relay design, but this requires a complete rewiring of the system, use of a WJ200 VFD (or a VFD that allows use of an external 24VDC power supply with source logic) and new switch gear. If using the WJ200 internal power supply it is limited to 100mA, so it is maxed out with one small relay (~70mA), one power LED (~15mA) and one proximity sensor (~15mA). One needs to be aware of the parts used in the build, so the power requirement is not exceeded. I have attached some designs for single relay systems in the attached file, some have been built other have not. So they are provided as a basic starting point, but provided as is and the user assumes all responsibility for their use. The designs are specifically for the Hitachi WJ200 VFD and will not work with other VFDs. All my newer VFD system builds use multiple relays, external 24VDC supply with 12 VDC step down converter, and more advanced VFD control and interlock safety systems because of the power limitations with the single relay design.


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## bench

Thank you so much. If I had to build from scratch I would pick up one of the designs but I would rather keep the current conversion and just add the proximity stop, and if required a DC power supply and a small relay. What I am thinking is connect the control output of a NO proximity sensor to a relay which switches a connection between P24 and an input of the VFD, and program the VFD input for STOP signal (code 21 on WJ200). With this when the sensor switch closes it would activate the relay which in turn issues a STOP signal to VFD. Would this work? And is an extra DC power supply required to run the proximity sensor or can it be run on the DC24V of the VFD? Or, is there a way to directly connect the proximity sensor output to VFD without going through the relay?


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## mksj

The problem is that you need to not have the system (usually controlled by the power relay) turn back on when you move the carriage away from the P sensor, and you need a bypass switch to be able to bypass the P sensor once it triggers. In the normal operation of the power relay, the spindle control must pass through the stop position to reset the relay and the relay has some form of electrical latching mechanism so it stays on once reset. I also use an additional mechanical switch should you override the P sensor and choose the wrong direction. I have done that on more than one occasion. The CODE 21 is a stop function only when using a 3 wire system with momentary switches, it is not a stop function in a 2 wire system. Most VFD emergency stop triggers put the VFD into an error state and prevent restart, but you then need to reset the VFD for it to accept any further commands. This is not a practical approach for this type of application.

The only way that "might" work is to interrupt the power to the DC relay in the stock control system. The stock control system uses a DC 24VDC power relay which is powered from the 24VAC going through a full wave bridge rectifier with its output connected to the coil of the relay. The problem is that this is not filtered DC but continuous 1/2 wave pulses, and the P sensor would pulse on and off as each waves goes to 0V. It would not work, in particular because of the high (fast switching) frequency of the sensor. There are some possible ways to smooth the DC, but it gets complicated and causes other problems.  You would be much better off in my opinion to use a mechanical limit switch attached to the micrometer stop/adjustable rail that would act like an E-Stop. This is what is done for most drive systems in mills with motor drives. Trying something else could be unpredictable and very dangerous. 

As I previously outlined, the single relay design is much simpler and easier to implement with an electronic sensor, then trying to do work arounds and patches on the original control system design.  Many individuals have built the single relay system and it has worked very well. Contactors are not designed to conduct low level signals, so a simple single 4 pole electrical relay VFD system is the easiest to implement. You remove the contactors and stock power relay and mount a 4P relay on the board. Alternatively fabricate another board, and swap out the boards with everything intact.


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## bench

Yes, it is a patchwork and not as elegant as your designs, but I already have a proximity sensor (PFK1-BP-3H) and so keep thinking about utilizing it. I came with a simple idea of inserting a relay switch (NO) just before or after the E-stop in series and a momentary bypass switch (NO) accross the relay. The relay is connected to the proximity sensor (NC) as in the diagram below. In this wiring the proximity sensor plus the relay is essentially an E-stop. When the carriage approaches the proximity sensor the switch on the relay will open that stops the lathe. To return the carriage the bypass switch must stay closed until the sensor switch closes. How do you think?


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## mksj

That would would work, but it is 3 relays that are sequentially tripped , so you will have a slight delay of a few 100ms and may be a small variation in the stopping position. You can use a small switching  universal switching power supply for the P sensor and additional relay, it can be 12 or 24VDC. They do make AC proximity sensors, but there switching times are much slower than the DC,  they are usually are NO and there are voltage drop issues. The only advantage is it would not require a separate DC power supply and relay.  I still feel the single relay design is very simple to implement and is a better overall solution.


----------



## bench

Thanks, Mark. I am glad for your confirmation. Yes, there would be a slight delay but more important will be consistency in stopping position, and hopefully the variation would be negligible.


----------



## Mr.Miz

I'm looking at doing this conversion with my Acer Dynamic 1340G. Would this be the right place to post pictures and questions for my conversion or should I open my own Form specifically for my Acer? For the most part I think I've got the conversion steps down I just want confirmation so I don't ruin anything.


----------



## mksj

I would recommend starting a new post under the machine manufacturer, the system/wiring would be a bit different. I have built VFD systems for Acer lathes, but they have been complete replacement systems. If the contactors have been previously used, the contacts arc over and do a poor job of conducting low voltage signals.  I do not favor use of contactors for switching VFD level signaling, this is  just a simple patch to get a VFD machine up and running in my oppinion.


----------



## Mr.Miz

mksj said:


> I would recommend starting a new post under the machine manufacturer, the system/wiring would be a bit different. I have built VFD systems for Acer lathes, but they have been complete replacement systems. If the contactors have been previously used, the contacts arc over and do a poor job of conducting low voltage signals.  I do not favor use of contactors for switching VFD level signaling, this is  just a simple patch to get a VFD machine up and running in my oppinion.



Thanks I'll start a new post. I've been uploading pictures into media as prep. I guess I'm having trouble getting over having all that front panel dead and having to mount the VFD somewhere and use it instead, that may all be "green horn" logic at this point but I'm just glad to have somewhere to start learning. Thanks.


----------



## dpb

For my own education, which is severely lacking in this area, what happens if you connect the 3-phase power from a VFD directly to the machine's electrical  panel, as if you were connecting 3 phase from the building electrical service?


----------



## mksj

The problem is that a VFD output is suppose to be a direct connection to the motor, and you can potentially damage/toast the output section of the VFD by running it into the machine and using the contactors to switch power. In sensorless vector mode, you may get an error message when the motor is disconnected, and the VFD cannot brake the motor because it is now disconnected.  You could potentially use the VFD in a fixed 60Hz and in a V/Hz mode, since you are powering the machines transformer, lights etc. they are designed for a specified frequency and voltage. Finally the output of the VFD is set to the specifications of the motor load, add other items and it will most likely fault or potentially damage the output. Any other power supply that has capacitors can also damage a VFD output. There are fixed output phase converters that are solid state or just use a RPC.


----------



## dpb

Makes sense, thank you.


----------



## bench

Installed the proximity senor using a Crydom D1210-B solid state relay. The relay is NC and the proximity sensor is wired to run NO. Works well. Repeatability is within  0.004mm.


----------



## mksj

Have had a number if inquiries for adding a joystick jog and 2 stage braking to basic PM 1340GT VFD basic wiring VFD conversions, so I have updated the information file and programming information.


----------



## Djl338

This is a great documentation for the 1340/vfd install.  I’m about to do this, and only thing I’m unclear on is the 220v input. I see it going to the board opposite the transformer, then is the 220v input to the vfd a separate feed from the breaker or is it fed back to the vfd from the control board?  I know this is not a new thread, but thanks in advance for the help and excellent write-up


----------



## cbarmer

mksj said:


> Many individuals buy the PM1340GT lathe as a 3 phase machine with the intent to convert it over to a VFD system, the usual VFD that is used is the Hitachi WJ200-015SF. Unfortunately the conversion often requires a somewhat complex and costly conversion process to optimize many of the VFD functions.  In many cases the machines may sit for many months if one is not familiar with how to do the conversion. I normally do these builds/conversions for other individuals, and have shared this information in this forum, but it is somewhat involved and very time consuming.
> 
> I normally do not recommend using contactors as relays for low level signals used to activate the VFD inputs, but if a machine is new and the contacts are not burnt, it is possible to rewire the stock control board (strip out the high voltage wiring and oveload relay), and use the contactors to switch the Forward/Reverse inputs contacts on the VFD. Once rewired, the machine will function the same as the stock machine would, and it will have the benefits of slower acceleration, faster deceleration and speed control.  A VFD Jog can be incorporated by using a dual switch block Jog switch.
> 
> The stock 3 phase (or single phase control board with a 3 phase motor replacement) PM1340GT system control board and switches are reconfigured so that the contactors are used to activate the VFD control inputs for forward and reverse, the JOG button on the front panel activates the forward contactor which will work exactly as the non-VFD configuration, i.e. the motor will jog at the same speed as the forward command would. The conversion is best made by removing the control cable wires from the control system terminal and removing the control board from the machine. This should only be attempted by individuals that are comfortable with rewiring systems, and want to get the machine into an operational state. The attached documents provides the recommend procedures, although I have converted the stock  PM1340GT control board to operate as such but have not done this as a complete conversion, *so you can try it at your own risk*. Please check all your connections, if you do not understand or cannot test the system, then have a system built for you and have an electrician work with the high voltage wiring. A basic overview of the changes are in the attached document.
> 
> Stock PM1340GT system control board
> View attachment 132921
> 
> 
> Modified PM1340GT control board with high voltage and motor connections removed. It retains the the stock 24VAC transformer and the controls work in the same manner as then non-modified board.
> View attachment 132918
> 
> 
> Full PM1340GT VFD Control Board System
> View attachment 132925


Just got my 3 ph 1340gt today and also got the vfd
But I noticed my electric panel is slightly different 
than the one in your pics. Will I have to deviate from the basic conversion as you describe it. I appreciate any advice and recommendations 
Thanks


----------



## mksj

I would follow the directions previously posted, I believe the only difference is that they may have a cover interlock switch and they changed the wiring color. If you have any problems PM me and I can try to help.
Mark


----------



## cbarmer

mksj said:


> I would follow the directions previously posted, I believe the only difference is that they may have a cover interlock switch and they changed the wiring color. If you have any problems PM me and I can try to help.
> Mark


I had noticed a few components missing on the transformer in my pic. I'll go ahead and start the conversion and most likely pm you during the process. Thank you sir
Charlie


----------



## PrecisionEcho

cbarmer said:


> I had noticed a few components missing on the transformer in my pic. I'll go ahead and start the conversion and most likely pm you during the process. Thank you sir
> Charlie



Hi Charlie, 

Glad to see you have started the conversion based on the latest PM1340GT models. I just made my order last Friday and plan to do the VFD conversion as well. 

Frank


----------



## cbarmer

Hi Frank 
Eager to get this running but stalled waiting on parts. Should have ordered earlier so I would have everything when lathe arrived. I'm goin with fwd/rev
toggle and pot on front panel. The support on this forum is awesome and very much appreciated
The idler gear on back of headstock has bearing in it ,well while cleaning corrosion inhib. off I noticed it was bad. You could feel the bearing 
notching as it turned. might wanna check yours out. i'll be replacing with quality bearing. Stay in touch and let me know how it goes. 

Charlie


----------



## litewings

Newbie here.  Looking at ordering a PM-1236T. Can someone tell me if this conversion is the same for this machine? The motor on this unit is 1.5hp instead of the 2.0hp on the 1340.


----------



## mksj

Yes, it is the same. The only difference is the motor setting are specific to the the 1.5 Hp motor.


----------



## litewings

OK, thanks for that. One step closer to ordering.


----------



## cbarmer

Wanna give mksj a big thank you for your support. Got everything wired up the way I wanted , very pleased with how it turned out.
If you are ever in my area give me a shout and i'll buy you a steak.

Charlie


----------



## Jason812

cbarmer said:


> Wanna give mksj a big thank you for your support. Got everything wired up the way I wanted , very pleased with how it turned out.
> If you are ever in my area give me a shout and i'll buy you a steak.
> 
> Charlie



I made Mark the same offer.  I would be willing to bet he could travel the country and not have to buy a steak for a while.


----------



## mksj

Thanks guys, I may take you up on the offer one of these days. I gave up eating beef about 45 years ago but I am game for anything else. I hope to be updating this post and adding some more details along with using an alternate Nema 4/12  VFD design that would not need an enclosure. The VFDs do add a lot of flexibility to the machines and 3 phase motors are a lot less problematic then single phase.
Mark


----------



## litewings

I have a 1340GT on order and gathering parts for the VFD upgrade. Have most of the parts as listed in this thread and mksj's instructions. Still have to get an enclosure. The length of the VFD is making it a large box and not real cost friendly either. What has everyone been using?


----------



## mksj

Minimum recommended standard enclosure dimensions are 12" wide, 14" tall and 8" deep. Having a clear front window is optional, but also additional cost and not needed. You normally do not need to view the VFD, but I recommend a hinged latched cover that is easily accessible. You need to order a metal back panel to mount the VFD and components. You also need a DIN rail to mount components that might require this mounting system. General recommendations, you may find something cheaper on eBay. A steel cabinet may not need any venting, preferably 12-14" wide, 16" tall and 8" deep should have enough volume. If active venting a fiber box is easier to cut holes in, either a hole saw or jig saw. Back plate material preference is galvanized steel > bare aluminum > painted steel/aluminum.

I have updated some of my recommendations for a 2-3 Hp VFD and have attached them. enclosures run anywhere from $75-150, the lower price range are for ones that come up on eBay, otherwise Automation Direct. If you do not want to use venting you should be fine with a 12 or 14x16x8 metal enclosure. At idle the VFD dissipates around 20W and under full load around 100W, so cooling should not be an issue. The VFD has its own internal fan which will move air through the box. The most important factor is that the VFD should have 3-4" of space above and below the VFD for air movement. 

I have outlined the following two options as far as VFD's the first would be the WJ200-015SF in a separate VFD electrical enclosure. An external braking resistor (68 Ohm 500W)  is required. I would have a power disconnect switch at the enclosure, and fusing is optional (but recommended in particular if the VFD is not on a dedicated circuit breaker). You need a minimum of a 20A 230VAC service, but 30A is what is recommended. Price wise you are looking at $300 for the WJ200 VFD and probably $300 for the enclosure/components. I would use the metal 16x12x8 or 16x14x8 enclosure with no venting/auxiliary fan. Wiring it up and programming the VFD is not that difficult with the documents posted (or provided by QMT), but these are recommendations and you need to be comfortable with wiring and compliance with all electrical codes. I usually recommend purchasing the WJ200 from QMT so if you have any service issues they can assist you. I have yet to see a WJ200 fail in the past 10 years and with 100's of units, but there is a vary small chance with any electrical device of an early component failure.

If you do not want a separate VFD enclosure, you can purchase a NEMA 4/12 (totally enclosed) VFD and mount it to the outer side of the headstock cabinet along with a braking resistor. The Teco Teco E510-202-H1FN4S-U is a totally sealed VFD with a power disconnect. It would need to be on a dedicated circuit as there is no provision for fusing. It would need an external braking resistor which would be mounted next to it. The VFD runs around $467 and the braking resistor (68 Ohm 500W) is around $60, so a bit easier and simpler than a full enclosure. I have not done an installation with this specific VFD model which is a new series, but I could provide them with the suggested wiring connections and programming parameters, which are different then the WJ200. A full enclosure is a better option if you need DC power supplies, additional breakers, etc.
https://www.wolfautomation.com/ac-drive-indoor-medium-duty-230v-2-hp/


----------



## litewings

I have the WJ200-015SF sitting on my desk as I type this, as well as the jog joystick and e-stop, necessary contacts and breaking resistor (50ohm, 500w).  Used the attachment on this thread that had some of the part numbers. Need to get the 5k pot yet and some shielded cable. Machine will be on its own circuit and it is 20A at this time.


----------



## Jason812

litewings said:


> I have a 1340GT on order and gathering parts for the VFD upgrade. Have most of the parts as listed in this thread and mksj's instructions. Still have to get an enclosure. The length of the VFD is making it a large box and not real cost friendly either. What has everyone been using?



I used a 14x12x8 enclosure, WJ200-015SF, and because I have a tendency to over kill everything, I used line reactors, which take up a lot of space.  There was enough room to mount everything but it took some planning and a larger box would have made life a little easier.  The box is mounted on the left side of the spindle cabinet 6 inches below the bottom of the drip pan and flush to the back.  This should leave enough room to mount the pump oiler above the box when I get around to getting one.


----------



## litewings

I think I have everything I need now for the VFD install. Found a used enclosure with back plate, DIN rails, and switch for a good price. Lathe shipped today so hopefully I'll see it by the end of this week. I do have one question at the moment though. I'm looking at page 9 of the Basic VFD install attachment that show the wiring and switches for the jog joystick and estop switches. I see a two stage braking switch between input 5 and the second estop. Is this on the machine somewhere or do I need to get another switch?


----------



## mksj

Neither of those are on the machine. You will need to replace the current E-Stop with a lighted E-Stop (with 24V lamp as a power indicator if using a joystick jog) with two NC switch blocks, you need a 2 way jog joystick if you want the ability to jog in either direction. The braking rate can be either stage 1 which is typically set to ~1 second ( the VFD most have an external braking  resistor) and stage 2 which I usually set to 3 seconds. You would use 1 stage for threading or turning to a shoulder, you must not spin the chuck at high speeds with 1 second braking (it will most likely result in an over-voltage buss error). I use a small toggle micro switch to set the braking rate.
Example of E-Stop, 24V lighted, requires an additional switch block. In my builds I use the IDEC AVLW series which are a bit nicer, and cost a bit more.





						22mm Pushbutton: twist-to-release, red (PN# AR22V0L-01E3R) | AutomationDirect
					

AR22V0L-01E3R - Fuji Electric pushbutton, 22mm, twist-to-release, emergency stop, LED illuminated, (1) N.C. contact(s), plastic base, plastic bezel,...



					www.automationdirect.com
				








						Contact Block: replacement, (1) N.C. contact(s), for multiple AR series pushbuttons and switches (PN# AR9B291) | AutomationDirect
					

AR9B291 - Fuji Electric contact block, replacement, (1) N.C. contact(s). For use with multiple AR series pushbuttons and switches.



					www.automationdirect.com
				




There are several different ways to wire a joystick jog, I have attached some different variations. The Joystick jog only comes with 2 NO switch blocks, the first two schematics require you buy 2 additional NC switch blocks. The third schematic uses logic diodes, these are typically 1A 400V like a 1N4004. Be mindful not to mix the machine 24VAC controls with the VFD 24VDC low level input controls.


----------



## litewings

Thanks for the info. I have the ECX-3510 and ECX-1040-2. My E-stop is the GCX-1226-24L with an additional ECX-1030. Also have the braking resistor. I have several toggle switches on hand so should be good on parts and materials.


----------



## Old Mud

mksj said:


> Thanks guys, I may take you up on the offer one of these days. I gave up eating beef about 45 years ago but I am game for anything else. I hope to be updating this post and adding some more details along with using an alternate Nema 4/12  VFD design that would not need an enclosure. The VFDs do add a lot of flexibility to the machines and 3 phase motors are a lot less problematic then single phase.
> Mark



  Well Mark i don't even have a vfd but after reading this whole thread (That i don't understand) If you ever visit Maine I will buy you a Lobster dinner !!
 It's a pleasure to see someone giving so freely of their expertise.


----------



## daveog

I'm curious if anyone has done the basic setup using the Teco E510-202-H1FN4S-U yet?


----------



## mksj

Not that I am aware of, but I can give you some help if you are interested. The major difference beyond the programming parameters is that there is a separate inputs for the Forward JOG and Reverse JOG. This actually makes it easier to wire up than the WJ200 which requires a JOG input to be activated (sets the speed) and also the forward or reverse input.


----------



## daveog

I may go that route. I’ve always done VFDs in enclosures and I like the idea of the stand-alone concept. The only downside I can think of is having to have the resistor separate and exposed.


----------



## mksj

Not really and issue since the resistor's I recommend are completely sealed and the wiring is embedded. You could also mount it on the inside of the VFD cabinet which I have seen done. It does not get warm so heat is not an issue. My original 1340GT VFD with the WJ200 had it in the headstock cabinet with the braking resistor mounted to the side, but I quickly went away from that to a separate VFD control cabinet because of all the add-ons needed for full control systems. I have built 1440GT systems with the WJ200 mounted into the headstock cabinet, as well as ERL and TRL lathes using Yaskawa VFDs. It all depends on the the machine, VFD design and functions.
TE Connectivity TJT50068RJ 


			https://www.mouser.com/ProductDetail/TE-Connectivity/TJT50068RJ?qs=sGAEpiMZZMtlubZbdhIBILA%2F3gb4Zcwrwsmmf1lm92I%3D


----------



## Endeavor1

I have a 1440 GT and I am thinking about going this route. Is it the same? Or is it at least similar?


----------



## Endeavor1

I have a 1440 GT and I am thinking about going this route. Is it the same? Or is it at least similar?


----------



## mksj

The specifics for the 1440GT is shown in this thread, which give a step by step recommend procedure. Please note that with all these machines there are some variations as to the wiring and wire color coding. But the same basic idea of using the contactor to switch the VFD low voltage input applies. If you have any specific questions PM me and I can see if I can help.









						PM-1440GT Basic Wiring Changes for using the Contactors to switch the VFD inputs
					

I previously outlined the use of new contactors to use to switch the VFD inputs when doing a basic 3 phase VFD lathe conversion, this retains the same functions (and interlocks) as the stock lathe and should operate the same. The VFD adds speed control, and acceleration deceleration control. In...




					www.hobby-machinist.com


----------



## frostheave

Mark, do you see any reason a Teco L510-203-H1-U wouldn't work for your PM1440GT 3hp upgrade?
Do you think Hitachi VFDs are significantly better and worth the extra cost above the Teco's?

Thanks so much for all your hard work!


----------



## mksj

Must of missed this question. The Teco L510 is not a good choice for the lathe in my opinion, but I still see a few people using them. There are several limitations, the most significant is that it cannot use an external braking resistor. The braking time difference can be 3-5 seconds, so with an external resistor the lathe can stop in about 1 second, w/o 4-5 seconds from speed. Other issues are limited number of control inputs that make it not suitable for the the 1440GT and limited for the 1340GT.  It has 5 inputs, two are used for the for/rev, two for jog for/rev, one for braking rate (1 or 2) if used, the 1440GT needs an additional base block (free run) input and I also use another input for the rapid stop command tied to the E-Stop (On the WJ200 there is the USP command).  If using the Teco VFD's then I recommend the E510 for lathes. Also the Teco and most other VFD manufactures use a separate input for the For/Rev Jog if you use a joystick. So the wiring is different then on the WJ200. Teco E510 is also available in a NEMA 4/12 sealed configuration with a power switch but still needs an external braking resistor.


----------



## frostheave

No problem.  Thanks for the detailed info.  Looks like the  WJ200 is the way to go.


----------



## oaklandish

So I am brand new here and pretty much new to machining. I don't count making a 6061 ball peen hammer in High school 30+ years ago. 

I just ordered the PM1236T with a 3ph motor for my home shop and will be doing this modification at some point in the future. I have gone through the entire thread and everything seems mostly understandable and I apologize if this has already been answered but, was there ever a master parts list created for the most recent PDF document. I have the one from March 2nd 2018.


----------



## mksj

I have updated the VFD enclosure information, but links and parts availability varies. It is more of a component list, plus some misc. items. Some things like wire ferrules and crimpers are not listed but available through multiple sources, if you have a question you can always send a PM. Basic install components are minimal, but depends on what you want to add.

You may want to add a basic tachometer, they are around $15-20 and an enclosure, they need a 12V power source so you can either get a 24VAC to 12VDC converter and connect to the 24VAC output of the transformer or a small 12VDC DIN rail power supply in the VFD enclosure.


----------



## oaklandish

Wow! thanks for the quick reply. I will review this stuff as throughly as I can and hopefully have more informed questions in the near future.


----------



## .LMS.

Mark has helped so many of us get these machines wired up.   I could not have done it without his documentation.


----------



## Todd727

mksj said:


> If using the Teco VFD's then I recommend the E510 for lathes. Also the Teco and most other VFD manufactures use a separate input for the For/Rev Jog if you use a joystick. So the wiring is different then on the WJ200. Teco E510 is also available in a NEMA 4/12 sealed configuration with a power switch but still needs an external braking resistor.


Deleted


----------



## Christianstark

Quick question from a noob. The 3 phase motor on the 1340gt says 9 amps max, but the WJ200-015SF output is 8. Anything I need to be concerned with here?


----------



## Ken226

Christianstark said:


> Quick question from a noob. The 3 phase motor on the 1340gt says 9 amps max, but the WJ200-015SF output is 8. Anything I need to be concerned with here?




It's rated for 150% of max current (12 amps) for up to 60 seconds.   I suspect you'll be just fine unless your turning a tank barrel for hours on-end.


----------



## xr650rRider

Christianstark said:


> Quick question from a noob. The 3 phase motor on the 1340gt says 9 amps max, but the WJ200-015SF output is 8. Anything I need to be concerned with here?



You must have gotten a different motor.  The nameplate says 9 amps FL?  That's closer to a 3HP motor.  I think the motor that came on my PM-1340GT was around 6 amps FL.

Now if your going by the manual it says 9 amps input but that isn't motor nameplate.  They are just trying to insure you don't power machine with 18 gauge wire.


----------



## Ken226

I believe he's getting that info from the manual.  It is rather optimistic compared to the the 2hp motors actual current draw.

From the manual:

Main Motor Horsepower: 2 HP
Voltage / Phase/ Amps: 220 Volt, 1 Phase / 12 Amps Max.
Optional: 220 Volt, 3 Phase / 9 Amps Max

It's actual FL draw, if I remember right is 6.6amps.

@Christianstark 

If the 9 amps you mentioned came from the manual, Could you take a look at your motor data plate and verify that you do indeed have a 2hp motor?  Perhaps snap a pic of the data plate.


Edited to add: 

Now that I'm thinking about it, I just assumed that you have a 2hp motor and were getting your info from the manual.  It could be a problem if you actually have a 3hp motor.


----------



## xr650rRider

The 015 is a 1500 watt drive.  1500 watts/746 watts/HP = 2.01 HP.  At 220 volts a 2HP motor would pull around 6.8 amps.  One of the settings in the drive limits current to 150% of 1500 watts or around 10.2 amps max.  Your actual line voltage is probably > 230 volts, so current draw will actually be lower.


----------



## mksj

The Pm-1340GT three phase motor is rated at 6.6A (2 Hp). You may be looking at the 1440GT motor or input single phase amps.


----------



## Christianstark

Hi All! Ken is indeed correct. I do not have my machines yet, but I am starting up my VFD materials list, so I went to the PM site and got that information from the manual. I am guessing that the manual is either wrong, or the manual referencing 9amps in motor plus other electrical needs. Thanks all for clarifying. WJ200-015SF goes in the shopping cart.

PM-1340GT 3PH PEP is what I have on order.


----------



## Christianstark

So I am already up to $700 for VFD and enclosure in my shopping cart, and I am probably forgetting some things.

WOW. 

@mksj shoot me a DM to discuss the possibility of having this built out. I am growing somewhat overwhelmed. I sent you a spreadsheet of my cart.


----------



## Genghis6400

Christianstark said:


> So I am already up to $700 for VFD and enclosure in my shopping cart, and I am probably forgetting some things.
> 
> WOW.
> 
> @mksj shoot me a DM to discuss the possibility of having this built out. I am growing somewhat overwhelmed. I sent you a spreadsheet of my cart.


Hey Christian I’m in the same boat as you are…. Please let me know what you find out.


----------



## Christianstark

Genghis6400 said:


> Hey Christian I’m in the same boat as you are…. Please let me know what you find out.



I have ordered a VFD and a braking resistor. Once I order the rest of my parts, I’ll share a list.


----------



## davidpbest

@mksj   Time to raise prices?   LOL


----------



## Genghis6400

Christianstark said:


> I have ordered a VFD and a braking resistor. Once I order the rest of my parts, I’ll share a list.


Thank you!!! I got both the Hitachi VFD and the Break Resistor already but have Not gotten the Box yet. Getting ready to bring the 220 power line to the designated area of the VFD.


----------



## Christianstark

davidpbest said:


> @mksj   Time to raise prices?   LOL


I was thinking the same! Everything I locate from Marks list is a good bit more expensive that when he posted that list. I sent him a spreadsheet of pricing from my cart.


----------



## Emery

I am planning on using a Hitachi WJ200-075LF VFD to power the 3 phase 5hp motor in my new PM 1440TL.  The input will be 220V one phase.  The instructions say to connect the input to L1, L2.  Would it be less stressful on the input diodes to connect the input to L1, L2 & L3 tied together?


----------



## Jason812

Emery said:


> I am planning on using a Hitachi WJ200-075LF VFD to power the 3 phase 5hp motor in my new PM 1440TL.  The input will be 220V one phase.  The instructions say to connect the input to L1, L2.  Would it be less stressful on the input diodes to connect the input to L1, L2 & L3 tied together?



I think that's why you double the size of the VFD to the motor on single phase and leave one leg open.  I'm no expert and didn't stay at a Holiday Inn either so I very well could be wrong.



			https://vfds.com/blog/can-a-vfd-convert-single-phase-power-to-three-phase/
		




> *Using Standard VFDs for Phase Conversion*​
> If your motor is too large for VFDs built for phase conversion, it is possible to use a standard VFD for your single-phase power supply. This is done by putting the two hot wires for single phase on the AC input for the VFD and leaving one input terminal open and unused. This does raise a few problems that you have to factor in.
> 
> 
> Because you are now concentrating the same amperage on two phases instead of three, failure of your VFD’s input diodes is likely to happen. To resolve this issue, you have to oversize the VFD to account for larger ampacities. A conservative rule of thumb is to double the size of the VFD you need.
> 
> 
> For example, if your motor Full Load Amps (FLA) is listed at 15, double that and size a VFD as if you needed to power a 30-amp motor. If you’re confronted with this situation, we recommend you call the one of our experts who can help walk you through this sizing process and find the correct VFD for you.


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## mksj

It makes no difference, the limitation is not the diodes but the capacitors and the increase ripple from single phase vs. three phase. On older VFDs they sometimes will connect L2 to L3 if there is phase loss circuitry, but it does not change the increased ripple on the buss. Also on single phase the current spikes are much greater which puts more stress on the components, adding a DC buss chokes decreases this and increase the longevity of components, this also decreases the input fusing/breaker requirements. Newer VFD's measure the input THD and if it exceeds a threshold value it will shut down the VFD. On a 3 phase input VFD's the terminals used for single phase varies by manufacturer. In some cases it makes no difference, in others sub circuits (like the fan) run off of only 2 terminals.


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## slodat

@mksj have you looked at Hitachi's new SJ-P1 drives for this setup? I have this newer drive on two CNC machines running the spindle motors with great success, from single phase supply. I have attached the pdf with this info. Of course, the drive should be sized for the output current on single phase. I am very happy with the newer drive. Curious about converting your drive parameters for use with the SJ-P1. I have an Acra 16x40 lathe I just bought, and I'd like to have your awesome control setup on the lathe. 

Thanks for your time!


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## Provincial

I'm getting started converting a Metal Max (Chinese belt drive) 1340 lathe to 3 phase VFD.  The lathe came without a motor, and was discounted heavily because of that.  I have acquired a Leeson 2 HP 1740 RPM motor and am using Mike's plans from this thread to fumble my way through this project.  I'm using the Hitachi WJ200 drive.

I bought a 240V AC power supply with a 10W, 24V DC output.  My plan is to use it for all the 24V DC control power, and am using a 24V to 12V converter to supply power to a digital magnetic tachometer that will display spindle speed.  

I have two questions about my 24V and 12V system.  First, since I am powering the 24V power supply from a manual disconnect (rotary) switch, can it treat it the same as if I was using the 24V DC power from the VFD?  I plan to use terminal 1 on the strip for this, and not connect anything to the VFD.  I plan to use terminal 2 for the 24V DC common.  Mike's plans use the emergency stop switch to disconnect the 24V control power while leaving AC power connected to the VFD, so my design should work exactly the same.  I'll be using the rotary switch to shut the machine off when not in use, and it will power down both the VFD and the 24V system.

My second question is about the 12V system.  Do I need to run a wire back to the step-down converter for the negative, or can I use the 24V common system for this?  If using the 24V common, I can see where it would be wise to put a diode in the 12V circuit to prevent back-feeding.

As I progress on this project, I'll post some links in this one to any posts I make elsewhere.  I'll do this because I feel that others will probably use Mike's excellent plans for conversions of other make machines, and this thread is the focus point.  I'll probably post in the Asian Lathes and Mills area, although my machine is very much like certain Jet and Enco models.  

Since my lathe has no electrical controls mounted in the headstock, I am using a 6.2x3.5x2.5" plastic junction box that I found on Ebay to mount the switches, speed control, and the tachometer display on the hinged gear cover at the rear end of the spindle.  I am mounting a 16x12x8 enclosure on the left side of the headstock stand.  This holds the VFD, circuit breaker, rotary switch, 24V supply, 24-12V converter, multi-relay, and a 20-lug terminal strip.  This will be very much like installations others have displayed on this forum.

I want to thank mksj for sharing his wonderful plans.  This thread enabled me to take on this project, and if it works as well as it should, I plan to do a similar conversion on my Atlas 12x36 that came with a 3 phase 1 HP motor from the factory.


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## mksj

I have no idea what design you are using, the basic install uses the contactors and the stock AC transformer. You cannot mix power for the relay controls with the VFD inputs on the relay designs I have done, not sure why you would want to do that since the VFD has its own internal power supply. I have done designs for other VFD's that use a single supply, but there are issues of electrical noise and voltage spikes from the relays that could damage the VFD inputs. I did one build that way and designed subsequent systems keeping everything separate. A 10W 24VDC power supply is pretty marginal, depends on the design but I usually use 65-100W. The system current draw with small relays and if I using a coolant contactor is around 500 mA 24VDC. On smaller builds I will use a step down converter to get 12VDC, otherwise I use two separate power supplies.

E-Stop is different then turning off the power, in one case you want to kill the run commands to the VFD and issue a fast stop, depends on the VFD and the control design. In some cases people choose to have it shut down the output section of the VFD (safe torque off), etc..


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## davidpbest

@mksj speaks wisdom. Follow his guidance.


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## Provincial

Mike, I'm not using any of the contactors.  I'm running my motor entirely off the VFD, and controlling power to the VFD with a manual switch.  My loads on the 24V system are the same ones your basic design powered with the VFD 24V output, with the exception of the tachometer, which is a pretty low draw.  The only relay in my installation is the 784-4C you call out.  I don't have a coolant pump or lights, and any I add will be stand-alone 120V.  

From what I have read on the web, I will be far ahead by not using any of the original contactors and electrical parts.  I am going to use the stock forward/reverse switch that is controlled by the lever on the carriage.  Other than that, everything is different.  The original system was single phase, and was prone to burning up motors because of a bad design.  

I could easily use the converter to power just the tachometer, and everything else with the VFD using your design.  I just thought that having the converter would eliminate the risk of overloading the VFD 24V circuit, which has very little capacity.


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## Provincial

I'm using your wiring diagram from post #44 on this thread.


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## davidpbest

The needs of the many outweigh the needs of the few.


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## mksj

I would use the VFD internal power supply, you are not going to overload it, that was the whole basis for the single relay design. It is simple and did not need an external supply. I have dozens of system designs, year past the single relay design was easy for others could follow, the current basic design is for use of the stock contactors to activate the VFD inputs and using the stock 24VAC transformer for lights, tach (24VAC to 12VDC converter), etc. Many people do not want to deal with tearing out and replacing everything. But if you have no  control system, the single relay design used with the WJ200 is a good, simple alternative. Hopefully you have the 4 pole relay, Automation Direct has been out of relays and sockets for months.
Mark


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## Provincial

Yes, I was able to find the proper relay, socket, and diodes on the Bay.  Based on your reply, I think I will just use the 24V power supply to run the tach system and use the VFD for the controls.  That will make the tach stand-alone and less likely to affect the control circuits.  I'll probably run two 8-conductor cables to my switch box, since I'll need 14 wires (3 for the Pot, 9 for the switches, and 2 for the tach) because I'm putting the jog forward/reverse switch there.  I can check around for some 12-conductor cable if it is critical to separate the speed control wiring from the others to minimize RFI.  In that case I would use a 4-conductor for the speed control and the 12-conductor for everything else.

It is a relief that we are now on the same "frequency."  I was afraid that I had overlooked something in the wiring diagram and was running off the rails.

Edit to add:  I apologize for calling you Mike.  I don't know how I mixed that up!  I'll claim old age.


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## Provincial

davidpbest said:


> @mksj speaks wisdom. Follow his guidance.


That is why I posted here.  I value his wisdom.  I'm glad we got past the misunderstanding and are having a productive discussion.


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## mksj

Not aware of 14C shielded cable, typically would be 15C or 16C. and pricing can go up quickly. Not that it is needed but the most cost effective would be a 12C and a 3C shielded in 18AWG. There is an eBay listing for a 15C in 24G, which would work but I find the small gauge wire to be a bit fragile. You also would want to use stranded wire as opposed to solid as it will be less likely to fatigue/break over time if there is movement. You will need to use crimping pins for the VFD end. Also be mindful that the VFD connections are correct and the jumper is moved.


			https://www.automationdirect.com/adc/shopping/catalog/cables/bulk_multi-conductor_cable/600v_control_cable/cc600-18-3s-1
		



			https://www.automationdirect.com/adc/shopping/catalog/cables/bulk_multi-conductor_cable/600v_control_cable/cc600-18-12s-1
		


25' Quabbin 8205 15 Conductor 24 Gauge Shielded Cable 25 Foot Length ~ 15C 24AWG








						25' Quabbin 8205 15 Conductor 24 Gauge Shielded Cable 25 Foot Length ~ 15C 24AWG  | eBay
					

Find many great new & used options and get the best deals for 25' Quabbin 8205 15 Conductor 24 Gauge Shielded Cable 25 Foot Length ~ 15C 24AWG at the best online prices at eBay! Free shipping for many products!



					www.ebay.com


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## Provincial

I did find an Ebay listing for 18/12 cable.  More than I need now, but if I do a VFD conversion on the Atlas, it wouldn't be that much excess.  Good brand name, and I think the PVC jacket should hold up pretty well.  About $2.00/ft.

Carol E2041S Riser Cable 18/12


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## B2

@Provincial 

I wanted 16 wires in a shielded cable for my 1440GT conversion.  But could not find it in a package that would fit through the hole in the side of my lathe.  I settled on two cables with, 20AWG stranded,   8+ground+shields and they slipped in nicely.    I agree with Mark, the 24 gauge is to fragile.  Even if it does not break it does not work all that well at the end connections.  I provided a link to the cables I purchased in the parts list of my conversion post.  See the Part 2 document.  These cables are made for the marine environment so should hold up well.  I spend quite a bit of time analyzing them and their metallic structures before I installed them.  I use elevator style screw connectors and they clamp well.  Since the individual wire have colors I also stripped the outer cover off so I would have colored wires to use.  I found that I could also Ferrule crimp them nicely to go into either the elevator connectors or the VFD inputs.  


B2 said:


> VFD conversion using solid state electronic components.


I think this may have been the product, but I know that I purchase a 50' roll which they no longer seem to offer.  



			https://www.amazon.com/Round-Signal-Tinned-Copper-Marine/dp/B088JW7F3K
		


" 20/8 AWG Round Signal Tinned Copper Marine Wire - Grade 8 Conductor Shielded Signal Cable - White Jacket, Black/Red/Green/Blue/Brown/Orange/Purple/Yellow - Made in USA "


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## Provincial

After I bought the 8-conductor cable, I found the 12-conducter cable I posted in #121.  I have since run a piece of 1/2" Non-metallic Liquid-tight flex conduit to a box mounted to the change gear cover and used one length of 4-conductor for the speed pot and one piece of 12-conductor for the other control wires and 12V + and- for the tachometer.  It all fit well in the conduit (I can remove and replace either cable while leaving the other in place) and I like the 18 gauge wire.  This leaves me with one unused wire in each cable.  I haven't hooked up the wires in the control box yet, as I haven't worked out how to make it fairly easy to service the internals of the control box, or design a mount and install the tachometer sensor.  I am also researching getting labels made for the switches on the control box.

I am moving ahead in fits and starts as I have lots of other things on my plate right now.  I did get all the switches and tachometer readout mounted in the control box, drilled the lathe stand for mounting the VFD enclosure and test mounted it, and mounted all the items on the back plate for the enclosure.  I also got the braking resistor mounted in the enclosure and drilled the hole for running the carriage forward/reverse wiring into the enclosure.  I got the master switch mounted in the enclosure and wired up everything except the SOOW cables in and out.  I'll wait on those until I'm ready do the final mounting of the enclosure onto the lathe stand.  That will be easy, since I am running them through a factory-provided removable plate that mounts on the bottom of the enclosure.  At that time, I'll also permanently mount the control box to the gear cover and support the conduit with a cushioned clamp.

I'm beginning to believe that I can actually complete this project!

As an aside, has anyone used the Analog Output from the Hitachi using the AM and L terminals (C028, code 20, Inverter Output Frequency) or Function C028, code 03, Digital Output Frequency)  to monitor frequency to the motor with a remote display?  I know I can display this on the VFD itself, but it will live behind a closed door and is pointed toward the left end of the machine.  I could remote mount the front panel, but it seems like that would expose it to the elements.


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## Just for fun

I'm setting mine up with 5 different cables, mainly because that's what I already had.  I'm using an 8-conductor 22AWG for the controls, 3-conductor 16AWG shielded for the speed pot, 4-conductor 14AWG shielded for the motor, 8-conductor 16AWG for the 12v and 24vdc power and a 2 conductor to a coolant solenoid.  I plan on just tie wrapping the speed pot and control cable together, and the motor and DC power cables together and keeping them separated as much as possible between the VFD cabinet and the lathe.  The cable for the coolant will run to the other end of the lathe, so it will be a separate run.

I have the VFD cabinet complete and mounted on the wall, now all I need is the lathe.


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## B2

Sorry, about the 8 wire cable post. My conversion was for a 1440GT and you have a 1340.  I think the opening into the front panel on your machine is a lot larger than on the 1440.  Basically, in the  1440 there is a hole through the cast material (~3/8" thick) into the control electronics enclosure.  With out opening it up a larger cable would not really fit.   I got two of my 8-wire and a small cable from the spindle Hall effect sensor through that hole just fine, but the original lathe cable with its thick OD insulation left little to no room for any thing else.   From the images I have seen of the 1340 opening it appears to be more of a slot between to pieces of metal so would be larger?   Anyway, my wires work fine for me.  I needed all 16 wires for my set up.

Now with respect to your question:



Provincial said:


> As an aside, has anyone used the Analog Output from the Hitachi using the AM and L terminals (C028, code 20, Inverter Output Frequency) or Function C028, code 03, Digital Output Frequency) to monitor frequency to the motor with a remote display



I looked into this and even provided one of the 16 wires up to the front panel to measure the VFD output frequency determined via analog output voltage.  Then I ask why do I need to see this frequency when I am already monitoring the RPM via the spindle its self.   The real thing I wanted to know was what frequency, approximately, the VFD was going to be running out BEFORE I turned it on so that I could preset the value  .... not after I turned it on.   Naturally, the voltage or frequency value coming from the VFD only shows up after the VFD is running the motor so this is of little value unless you are varying the speed during operation, like in a paper mill, and want it for feed back control.  So I just installed a volt meter in the front panel and connected it to the pot output.   This voltage then tells me where the pot is set before I turn on the lathe.  The voltage in either case is from 0-10 volts and so is only proportional to the VFD frequency not a number that equals the frequency.   I also measured the voltage from the pot to the VFD to determine the frequency vs pot output.  I found that the frequency was not exactly linear with the pot wiper voltage, but was close enough to give me an idea of what the resulting voltage would be.  This is probably due to the VFD loading down the pot a bit as the input to the VFD is not high impedance.    I then set the max frequency on the VFD to about 108 Hz.   This then resulted in the voltage at the wiper pot, and so my volt meter, to be 6 volts when the frequency out of the VFD was 60 Hz.  The linearity is not so bad that the volt meter reading is very far off at the lower frequencies or higher frequencies... and I seldom run the lathe anywhere near 108 Hz any way.  By using a max frequency near 100 Hz the volt meter measurement in Volts is equal to the Frequency/10.  So I do not have to do much of a mental conversion!  

Some may express concern that the panel meters generate noise and hooking one of them up to the pot output, going directly to the VFD, might create a problem for the VFD.  At least in my design I have not found this to be a problem at all.  If you did then just hang a capacitor on the line to kill and noise the spikes.  

Lastly, I gave a link to my conversion earlier at posting #121.  At that link there are photos and documents about my conversion and the Part 2 appendix provides a list of components use in the conversion.   There in those photos of the front panel, and below,  you will see the three meters that I put into it along with all of the other devices.  I monitor, the Spindle RPM, the VFD input voltage, and I have a spindle Revolution Counter.  The counter also has an additional feature so there is a mini switch to select that mode.    I posted the Excel program I used to generate the G-code to make the holes in the panel.  It is linked at the conversion site.  I found it especially handy when I remade the panel meter and needed to add devices and move the previous ones around.    I found these RPM and counter displays, which are smaller than most, to be quite visible and readable.  They work nice and cost about $14 each.... from China though so take 4 weeks to get.   The design and layout is nice an neat with no EXTERNAL meters!  If interested, you may want to check the operating voltages as not all meters will work on 24Vdc.  I did drop the 24Vdc down to 12 via a simple 3 terminal regulator at one point.  I think it may have been for one of the meters and then used on all three.  A lot of these devices are made to be used in automobiles which do not usually run at 24 volts.  

By the way, I think the front panel for the 1340 is almost exactly the same size as that of the 1440.  It is the same width, but the 1340 may be slightly taller.  I do not know the dimensions of the inside of the 1340 front panel enclosure.  I think the devices that I use would also work with your conversion.  

Dave L.


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## davidpbest

@Just for fun if you're interested, here are the dimensions for the control switch panel on my 1340GT.   Others report the positions of the screw holes that mount that panel vary from machine to machine - I assume they are individually hand drilled/tapped at the factory.  I had FrontPanelExpress make replacement panels and if you want those design files, let me know - happy to share.


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## B2

Hi @davidpbest 

I am curious,  do you have info, pictures and dimensions you could share on the hole (enclosure) that is behind the panel? Depth, width, ...  where the wires come in, etc.

Dave L.


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## Just for fun

Thanks David,  I think the 1236T has different size opening.  I may still take you up on the files for the panel.


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## davidpbest

B2 said:


> Hi @davidpbest
> 
> I am curious,  do you have info, pictures and dimensions you could share on the hole (enclosure) that is behind the panel? Depth, width, ...  where the wires come in, etc.
> 
> Dave L.


I have some photos and another drawing that might help.  As part of my 1340 build, I completely stripped the machine back to bare metal, did a proper Bondo job to the castings, and repainted it.  So I have photos of all that that will give some idea what the head casting looks like stripped down.  I also implemented a one-shot oiler system that dealt with the mickey-mouse oil squirt-ports on the sides of the headstock, and that aspect caused me to make a new bottom plate that distributes the oil to the Norton gearbox and is also the bottom mount for the switch panel.

Shown below at the red arrows is how the cable system comes into the machine for the front panel switches - through a gap.  The green arrows point to an aluminum casting who's primary purpose is to provide an attachment point for the front panel to screw into along the bottom.






This photo will give you some idea what the cavity looks like behind the switch panel - that bottom support casting for the front panel is not shown in this photo - it just rests in place.






This photo shows the oil distribution plate I made to replace the factory unit.  That process if fully _*documented here*_. 






This is how it all worked out with the new plate installed, the new switch panels, and how I provisioned for the wiring and oil connection.   Note that the switches are also at an angle, and I had to dish out the replacement plate to give clearance to the mechanical aspects of the switches behind the panel.






This is the drawing for the oil distribution plate.  From this you can get approximate dimensions front to back for the cavity.  The casting walls on either side of the cavity are about 1/2" thick, but they taper as you can see in the first few photos, and the front is sloped at an angle.  A clearer drawing is attached.





Hope this helps.


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## mksj

The 1236T has a shorter front panel, PM me if you want a file for the front panel, these days they run about $100 for the new switch panel.


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## Just for fun

Thanks Mark, I'll do that.

Tim


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## B2

Thanks David.  Nice.  That helps me understand a lot better.  There is a lot more room for the wires to come thru in the 1340 than in the 1440.  The oiling system is not a great factory design, but you seemed to have a nice fixed for it as well as that nice drip pan you made!  It is not clear what holds the drip plate in place.... just the two front panel mounting screws?   The 1440 has a reservoir and so does not consume oil or drip it out the bottom.  Do I understand correctly that drip plate siting on flat surfaces is all that keeps the oil from getting into the electronics enclosure. No o-rings or gaskets!

I understand you why dimpled down the plate surface you made due to the front panel being at an angle and panel mounted devices possibly bottoming out.  However, it appears that you mounted the devices up high enough to avoid needing it.    In the 1440 the panel is vertical, but there is also a ~1" hollow area in the enclosure extending down from the bottom edge of the front panel the provides extra space.  Although I did not need it, I used just a little of it for the bulky part of the E-Stop switch. Nevertheless, the wires lay on the bottom.

The depth is a little hard to judge, but from the photo of the cavity with the new oil drip pan plus the drawing of your new oil drip pan would indicate that the depth is about 3.4".  The height is not as large as the panel due to the oil drip pan.

Great to see those lovely Norton Gears!

Dave L.


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## B2

Hi @davidpbest

When you were refinishing your PM1340GT did you by chance take the apron gear box apart.  If so did the gear arrangement look any thing like the manual shows?  It appears to be similar to my 1440GT but I cannot figure out how the gears work in it.  The manual is very poor, but at least it give some of the gear dimensions.  The 1340 does not seem to even do that.  

So here is the reason for the question.  On both machines and many others it says that the ratio between the Power Feed and the X-Feed rates are simply 2:1 (or 1/2) however, I have made a quick attempt to measure them and I get a number more like 3.14:1 not the factor of 2.  I think the tables on the lathes are wrong and miss leading.  Most folks could not care, but still....  I am going to measure mine much more accurately and see exactly what the Power Feed and the X-feed rates are.   I think the lathe table for The power feed is somewhat close.  But not the X-feed.  

I wonder how many other lathes are like this?

Maybe I should take this to another string and ask the general question about x-feed rates.


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## Firstram

Easy enough to measure. Engage the x feed and turn the spindle over by hand a few turns to take up any backlash. Zero a dial indicator on the tool post, rotate the spindle 10x and read the travel. Divide by 10 to get .xxx/Rev. Repeat the process to get the travel numbers, compare with the stated travel for the feed you chose.


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## B2

Hi @Firstram 

Thanks.  Yes, I have measured them that way as well as with far more turns on the spindle to get more accurate results.  The end summary is that the table values in the manual for the Power Feed are not too bad, but not exact.  However the x-Feed Table values are way off.  Typically rather than the ratio of 1/2 of the Power Feed values which the tables on the lathe as well as in the manual say.  The measured results are more like 1/3.xxx.  So I want to know what is going on inside the gear box that is different from what the manual says.   The manual's description of the gears is incomplete at best.  In the end of course I will go with what I measure, and if I do not figure out the gears then it will just have to wait until SOME day when I or someone else take the apron apart and describes it better than the manual.  By the way, the manual's description of the main gear box is also poor and incomplete and after a lot of study I concluded it could not work with the geometry that was described in the manual.  It is not nearly as straight forward to analyze as a Norton gear box.  

I have a unique instrument for this measurement.  I have an electronic counter to count the spindle turns to 0.1 of a turn.  I also have a good magnetic DRO which I have checked the calibration in both directions.  So I can run the spindle for a long time and just get the turns on the counter.  I should be able to find both feed rates rather accurately.  Here is the counter I built in...  


B2 said:


> I was adding a counter to my VFD converted PM1440GT



Dave L.


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## Provincial

Dave, on my Metal Max MM-1340LB (China-made Jet/Enco belt drive clone) the manual states that the carriage feed rates are 0.0036-0.1005 and the cross-feed rates are 0.0012-0.0345.  That is pretty close to 1/3.  I believe that all the gears in the apron have the number of teeth listed except the one on the end of the carriage feed handwheel, but that gear is not in the power train of the powered feed.  They also don't call out the tooth count on the cross-slide feed screw.  I can take photos of the manual pages and post them if you desire.

Very nice conversion!  I am envious.  I have all manual equipment, but am converting to DRO's and VFD's.


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## Provincial

Rather than clutter this thread, I posted the photos on B2's thread about the cross-travel speeds linked here:

https://www.hobby-machinist.com/threads/x-feed-rates-on-pm-lathes.98071/


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