# Getting a 1440GT (Which VFD, and other small questions)



## LVLAaron (Jan 30, 2021)

Planning on ordering a 1440GT Lathe.

I will get the 3 phase version. Slow spindle speed will be important to me at some point (chambering barrels) 

I've been through this thread and read the diagrams in the thread titled "The Pm-1440gt Has Landed" by @jbolt  (new account, so I cant share the link)

I've also seen and fully understand Clough42's 7 part series on converting his lathe to run on a 3 phase motor with a VFD. (hnew account, so I cant share the link) 

I'm comfortable with electronics, but everything that @mksj has in his wiring diagrams is a little overwhelming, especially without having the actual lathe to look at in person.

So, a couple questions. 

* It seems like the Hitachi WJ200 is the VFD that is preferred. _*There are several sub-versions of it available... which one do I want? 

* *_To get the lathe running, I don't need all of the extra things that mksj has done, correct? VFD with the basic lathe controls wired through it (direction, speed, stop) is all that would be required, correct?


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## Cadillac (Jan 30, 2021)

For/rev switches stop button and a main power switch. Acouple fuses to be safe


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## davidpbest (Jan 30, 2021)

Now that I've used my 1340 with Mark's controls system for 5 years, I would not be without the jog joystick or the proximity stop.  Very useful additions.  I'm also glad I upgraded to a vector-rated motor for more speed range and better torque.  I use jog all the time to thread using smaller taps and dies, and the proximity stop takes the pucker factor out of boring to a blind hole bottom or threading to a shoulder (most of my work is metric).  YMMV.


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## Kiwi Canuck (Jan 31, 2021)

Welcome to HM Aaron.

You can order the Hitachi VFD from QMT (Precision Matthews) when ordering the lathe and they will supply the correct model, also saves on shipping, bought mine from them.

Probably the WJ200-022 for the PM1440GT
Here's a link to the unit, good for 3 HP and single phase input.








						WJ200-022SF
					






					www.driveswarehouse.com
				




I agree with David Best, the jog feature is very useful and I also love the soft start and two stage braking provided by the VFD combined with a large resistor.

David.


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## mksj (Jan 31, 2021)

The circuit design I provided for JBOT is about 3 versions from my current design, unless one is well versed in VFD control systems, I would not recommend attempting it. There are also other components that are not listed in the control schematic and his system was built as an integrated single enclosure system. There are a number of variations and each persons build varies depending on the individuals requests.

The basic 1440GT install is listed at the end of this thread, it is very easy to follow the installation pictures and will get the lathe working with the VFD and has been done by numerous individuals. The information provided is based on the use of the WJ200-022SF VFD, which is the 3 Hp single phase input model. I have posted in different places recommendations for VFD enclosure parts, the 3 Hp VFD needs 10AWG input wire, 14AWG is fine for the motor and an external braking resistor is required, the specifications are listed in the document.








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

Sure does




					www.hobby-machinist.com
				




The complete replacement control systems with proximity sensor provide a range of VFD control features, the sensor gives very repeatable stopping for threading, shouldering or blind boring. It is an additional aid, but does not replace good machining practice. Some individuals choose to put the VFD in the headstock cabinet, some in a separate VFD cabinet either mounted behind the lathe or on the side. This is a system I recently made for an individual that will be using a separate VFD enclosure and also requested a custom micrometer stop.


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## Rifleman1384 (Jan 31, 2021)

Aaron, 
Hi and welcome. 
You are in the correct place, everyone here is very helpful. Especially Mark and Dave that have already posted here. Look in the thread Mark has a video using his proximity stop while threading. https://www.hobby-machinist.com/threads/erl1340-thread-cutting-with-a-proximity-stop-system.88124/

 Man the photo above looks familiar and that is one sexy carriage stop, I wonder who's it is (wink,wink).

Yes you can get the VFD from PM and they will ship it with the machine, they do try and keep them in stock, from the research I have done 3ph is the only way to go. Flip side if you get the VFD on your own you can have it installed already if you are going with the external enclosure. Mine will come with the machine.

The install instructions for the system (above Picture) are very well put together, I get a few pages in and wondered if I was over my head ( I am not an electrician or electrical engineer) I read every page of the instructions and then went back over it again. It seems pretty straight forward and I am confident it looks a lot harder than it will really be.  

I read everything I could find and spent way to much time thinking about if i really needed (wanted) the full conversion (upgrade) or just run the machine with the VFD only just as the machine comes out of the box. I will be doing some of the same work you are planning. I decided in my case it would be better to just do it all at once instead of a re-do later. Something to think about, please be patient there will be delays in getting your machine, not bashing PM at all with the new times we are in so many things are out of anyone's control. You accessorize will you are waiting on the machine I told the boss lady that I'm just getting the right purses and shoes while I'm waiting on the outfit and she has not questioned the arriving boxes.

Many here may suggest to try and upgrade the 3 jaw chuck that comes with the PEP package, I tried that several times with my order and the last response was that the better chuck would not be available for several months (summer likely). I will start with the 3 jaw and we will see how good it is and if I keep or replace it. Someone else has posted that they were told PM could get them a Bison or TMX if they wanted. Please make sure if you get a 4 jaw from PM that you understand the thru hole in the chuck is smaller than the spindle bore if you will be needing all of the spindle bore at some point. 

Again Welcome and Good Luck, remember ask, ask, ask. The folks here are very helpful in sharing their knowledge and experience.

Steve


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## LVLAaron (Jan 31, 2021)

Thanks everyone! - This has been very helpful. Almost everything makes sense. 


The only thing I'm not fully understanding yet is what the factory contactors are being used for as described in *"PM1440GT Basic Wiring Changes for using the Contactors to switch the VFD inputs 23 DEC 2018-1.pdf" *

Looks like they're "between" the control panel switches/controls and the VFD - the controls cannot be directly wired to the VFD?


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## mksj (Jan 31, 2021)

The VFD output is wired directly to the motor, the contactors are not used for this purpose. The VFD has low voltage/current inputs that can be programmed for many VFD functions, so you need a means to activate these inputs and maintain the machine safety interlocks. You remove the high voltage wiring to the motor run contactors and use one set of inputs to control the VFD forward and reverse input commands. If you want other features, you need to rewire the other switches so they operate the VFD inputs for those functions (like low speed jog). You will also need a speed pot. Contactors if new work acceptably to switch low voltage/current connections, but once used they build up contact resistance from arching and are less predictable. So this is a simple approach to using the VFD, but not an ideal dedicated control system. It is all a bit overwhelming when one cracks open the door to trying to understand how to use VFD's, once you have done one it gets more straight forward. VFD;s should be wired with all the safety interlocks, also with a manual foot brake, it requires shutting down the run commands to the VFD and activating the coast function to a stop on the VFD.


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## LVLAaron (Jan 31, 2021)

Thanks again for the help. I've started ordering some of the core parts. (VFD, resistor, breakers, box, fuses, switches, etc) 


Being new to the forum, what's the preference when I have new stupid questions? Keep this thread going, or start a new one?


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## davidpbest (Feb 1, 2021)

You're a braver man than I and have a lot of work ahead of you.  Good luck.  I'm sure Mark will be standing by to assist.


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## LVLAaron (Feb 1, 2021)

One circuit at a time.


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## jbolt (Feb 2, 2021)

Don't sell yourself short. Once you get started putting it together and wiring you will find it isn't really that hard, particularly with the support on this forum. 

You can continue posting on this thread or start new. Continuing this thread isn't a bad idea since you referenced older builds that have been refined and simplified as it will help someone in the future. Either way, those that help answer questions will follow the thread. 

Post lots of pictures. We all like pictures, especially new stuff.


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## LVLAaron (Feb 2, 2021)

I'm confident I can do it. I also have a friend with a 1440GT that put his own kit together. Look forward to the lengthy thread and my crappy hand drawn diagrams!


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## oregontripper (Feb 4, 2021)

Watching with interest, although planning to run mine off a RPC. 

Good luck.


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## LVLAaron (Feb 4, 2021)

I'm on my way.


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## LVLAaron (Feb 16, 2021)

A timely video was just put on youtube by a fellow PM machine user:


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## 7milesup (Feb 16, 2021)

^^^And a fellow H-M member ^^^   He has a thread on here somewhere, not about the build, but a link to his video.


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## 7milesup (Feb 16, 2021)

I too am considering a VFD.  I just ordered an Eisen 1440E so will be following along.


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## Ischgl99 (Feb 16, 2021)

The nice part about VFDs is you can get started with just the basic functions and add to it later as needed.  I‘ve only had my lathe running for a month, but haven’t added jog or variable speed to it yet.  I’m looking forward to seeing what you do with you lathe.


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## Todd727 (Feb 16, 2021)

I have a question about the braking resistor.  I don't understand why it is listed as a must add.  The VFD has a built in braking resistor, which will slow the lathe faster than the single phase cutoff does.  For emergency stops, the foot lever has a friction brake.  I can understand if someone WANTS the lathe to stop faster, but I don't see that it is required.


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## Phil_C (Feb 16, 2021)

I don’t remember seeing this brought up before, with the foot brake on there I’d want to turn the VFD off when it is pushed if you leave it like a stop then the VDF will fight the brake. I know people used these on the 1236t and 1340gt that do not have the mechanical brake, but I’d be scared to. E-stopping with the drive stops the mass through the gear train, I’ve seen what can happen to equipment when doing it just one time. Slow stops are one thing an E-stop is another.

Read the manual carefully there will be different ways to stop it know the difference between them, there may be a normal stop that may ramp down, a stop that might be called an Estop that electrically stops the motor and then an off that disconnects the output from the drive.

On a lathe with a foot brake you want Off (disconnected) and the carriage switches to a slow ramp.

I have seen E-Stops on a drive that disconnect the drive and something else that will do a hard stop of the motor.

Hopefully you get the idea.

Phil


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## Ischgl99 (Feb 16, 2021)

Todd727 said:


> I have a question about the braking resistor.  I don't understand why it is listed as a must add.  The VFD has a built in braking resistor, which will slow the lathe faster than the single phase cutoff does.  For emergency stops, the foot lever has a friction brake.  I can understand if someone WANTS the lathe to stop faster, but I don't see that it is required.


A braking resistor is only required if you need to stop a high inertia load from a high speed fast.  The VFD has the ability to absorb some of the rotational energy.  My normal mode of operation is coast to stop, and when threading I have the deceleration set to 1 second.  I have tested my 1236T up to 900 rpm with my 8” 4 jaw chuck and don’t need a braking resistor on my Teco CV7300 VFD at 0.5 deceleration time.  

The advantage of coast to stop is if something is preventing rotation of the spindle, coast to stop will stop immediately, possibly preventing damage.  Using deceleration, the VFD will want to continue to drive the spindle for the duration of the deceleration cycle, or until it trips out.


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## Ischgl99 (Feb 16, 2021)

Phil_C said:


> I don’t remember seeing this brought up before, with the foot brake on there I’d want to turn the VFD off when it is pushed if you leave it like a stop then the VDF will fight the brake. I know people used these on the 1236t and 1340gt that do not have the mechanical brake, but I’d be scared to. E-stopping with the drive stops the mass through the gear train, I’ve seen what can happen to equipment when doing it just one time. Slow stops are one thing an E-stop is another.
> 
> Read the manual carefully there will be different ways to stop it know the difference between them, there may be a normal stop that may ramp down, a stop that might be called an Estop that electrically stops the motor and then an off that disconnects the output from the drive.
> 
> ...


You are 100% correct on that.   If you have it set up for a timed deceleration, you would want it to switch to coast to stop so the brake could stop it without fighting the drive. 

There are three emergency stop strategies.  If you do a controlled stop, you are then supposed to de-energize the drive once it reaches zero speed since you don’t know if the reason for the e-stop is mechanical or electrical.  Most of the industrial equipment I worked on had so much rotational energy that decelerating the equipment was not practical, so the e-stop strategy was to de-energize everything since you didn’t know why the e-stop was pressed.  If it was for an electrical reason, you would not want the drives trying to slow the machine down, and if it was mechanical, you couldn’t slow it down fast enough to make a difference.


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## mksj (Feb 16, 2021)

The use of a free run command also known as a base block command is indicated in the 1440GT basic VFD install document, this command needs to be issued when the foot brake is engaged and requires replacement of the stock brake switch with a 2 pole model. One side is left as the default wiring which disengages the run command and the other pole is used to send the VFD free run command. 

On E-Stop there are different approaches, but typically you want to kill the run commands to the VFD and also stop the machine as quickly as possible. Disengaging input power to the VFD defeats the rapid braking. I do recommend an external braking resistor in this application, it helps to decrease the braking time when needed and also will decrease the risk of getting an over voltage buss error with too rapid a stopping and butting the VFD into a free run shut down.


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## Todd727 (Feb 16, 2021)

Ischgl99 said:


> A braking resistor is only required if you need to stop a high inertia load from a high speed fast.  The VFD has the ability to absorb some of the rotational energy.  My normal mode of operation is coast to stop, and when threading I have the deceleration set to 1 second.  I have tested my 1236T up to 900 rpm with my 8” 4 jaw chuck and don’t need a braking resistor on my Teco CV7300 VFD at 0.5 deceleration time.
> 
> The advantage of coast to stop is if something is preventing rotation of the spindle, coast to stop will stop immediately, possibly preventing damage.  Using deceleration, the VFD will want to continue to drive the spindle for the duration of the deceleration cycle, or until it trips out.


Agree and understand that the foot lever has to put the VFD into "coast" or "free-run".  That makes sense.  In fact the factory foot brake can be pressed lightly to do just that, so the switching is already there.  Pressing further will apply the friction brake.

My SB is setup that way with the normal off switch and the emergency stop.


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## Todd727 (Feb 16, 2021)

mksj said:


> The use of a free run command also known as a base block command is indicated in the 1440GT basic VFD install document, this command needs to be issued when the foot brake is engaged and requires replacement of the stock brake switch with a 2 pole model. One side is left as the default wiring which disengages the run command and the other pole is used to send the VFD free run command.
> 
> On E-Stop there are different approaches, but typically you want to kill the run commands to the VFD and also stop the machine as quickly as possible. Disengaging input power to the VFD defeats the rapid braking. I do recommend an external braking resistor in this application, it helps to decrease the braking time when needed and also will decrease the risk of getting an over voltage buss error with too rapid a stopping and butting the VFD into a free run shut down.


Thanks, I did see a video where someone was dialing in the stop time on a Grizzly and using too short of a time spiked the DC voltage to the point that it went into free run.

I'm still not sure I'm going to convert my 1440E to 3PH, but I will have to set up a VFD for my mill that is coming in as a 3PH machine.  One problem I'm going to have is the 240V outlets don't have a neutral, which is going to be a problem for the DRO.  I do have 120V outlets right next to the 240V, so I may just plug the 120V equipment into the separate outlets vs. running new wires.


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## .LMS. (Feb 16, 2021)

Todd727 said:


> I can understand if someone WANTS the lathe to stop faster, but I don't see that it is required.



It's required because it's cool.


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## davidpbest (Feb 16, 2021)

Todd727 said:


> I can understand if someone WANTS the lathe to stop faster, but I don't see that it is required.


This guy might disagree with you.


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## 7milesup (Feb 16, 2021)

Good Lord...


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## Todd727 (Feb 16, 2021)

.LMS. said:


> It's required because it's cool.



I get that.


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## Todd727 (Feb 16, 2021)

davidpbest said:


> This guy might disagree with you.


Great, but that isn't what I'm talking about.  In fact, the red e-stop means I'd have to move past the chuck to get to it, increasing the odds I'm in the danger zone.  Again, the 1440 has a foot brake, which is much quicker than any braking resistor.


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## Phil_C (Feb 16, 2021)

I wish I could un-see that. I still nightmares about one I had to watch in probably 1985 of people cleaning out an industrial bread dough mixer that...


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## Todd727 (Feb 16, 2021)

Phil_C said:


> I wish I could un-see that. I still nightmares about one I had to watch in probably 1985 of people cleaning out an industrial bread dough mixer that...


You and me both.  I guess I could post pictures of a mechanic that went through a jet engine, but I bet that isn't necessary either.


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## mksj (Feb 16, 2021)

The braking resistor is not necessarily for the E-Stop, it is for quick braking when threading or needing quick stopping times when turning to a shoulder or internal end point and prevent damage. The last thing you want is for the lathe to trip out or braking to be delayed. On the same aspect, one needs to understand that one cannot keep shortening the braking time an expect it to work every time.  Proper setup and testing is required and is different for every machine and VFD. Foot brake is quick, but the electronic braking can also be quite quick, in particular when you need to think about hitting the foot brake. Can't say I have yet to use my lathe foot brake when the lathe was running, only when stopped and tapping. I actually like the idea of a dead man switch that you need depress for the machine to run and if released the machine goes into fast stop. Some VFD's do have an emergency stop input which will ramp down the speed as quickly as possible without tripping and error message, there is also inputs to disable the run output section of the VFD's as an additional safety input when the E-Stop is engaged. Lots of options depending on the model.

As far as 240VAC with a neutral, it is not uncommon and there are plugs designated as such. I use 4 pole twist lock plugs on both my lathe and mill so I have both 120 and 240 at my machines with separate sockets. I use supplemental breakers for the sub circuits. Also many DRO's these days either are switchable for 120/240 VAC input or have a universal input power supply. The DRO is hard wired into both my machines so comes on with the main power switch.


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## Steve R (Feb 16, 2021)

I got my 1440TL in Oct of 2020 and have been using it with a VFD just to supply 3ph power and using the foot brake to do most of the braking. This weekend I done the full VFD conversion and must say, that using the electronic braking is REALLY nice. Flip the direction level to stop and within a second the spindle has stopped. Don't have to step on the foot brake. One less thing needed to operate. Can you live/operate without the electronic braking, yes. But it is a very nice option. It actually saves some time, instead of stepping on the brake, even though it is a small amount of time, you are taking that time and moving on to doing something else (grabbing a mic, making adjustments, inspecting the work, etc.


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