# Picked up a Mill.  Now to power it



## Gman45acp (Apr 30, 2021)

Got this Maxport 1992 Taiwan mill
Was in basement and has seen little use. For course it’s 3 phase.  It is a step pulley head.  So go rotary phase converter or VFD.  Think VFD as will be able to vary RPM without changing belt.  They look king of complicated to set up and don’t know if this 70 year old will be able to figure it out.  What has been your experience if you have gone this route
Got the mill, Taiwan Kurt copy vice 5.5 inch, set of collets, two chucks One small one larger, 14 inch rotary table , need to sell that to big for my needs, and a couple of fly cutters.   Need to add z glass scale I have an extra electronic box to add 
thanks


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## ttabbal (Apr 30, 2021)

Looks nice! 

There are 3 common options. Static and rotary converters, and VFDs. Converters are nice as you don't have to mess with switches or other electrical controls. VFD lets you vary speed easily, but there is more wiring. The mill probably uses a simple control setup with a reversing switch and not much else. Probably the easiest setup for VFD. You can even just use the controls on the VFD itself so you just have power in and out. 

Static converters cause some power loss, rotary can drive many machines. So that can be a win for them.


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## BladesIIB (Apr 30, 2021)

Looks like a great find.  Congrats!  The VFD learning curve is steep but worth it in the end in my opinion.  I went that route on a lathe last year and glad I did.  Lots of support on this forum if you choose the VFD route.


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## jwmelvin (Apr 30, 2021)

I like your mill. I recently got a 1980 Millport, made in Taiwan. It also has a 3-phase motor (2hp, 1700 & 3400 rpm) on a step-pulley head. The prior owner had used a static phase converter. I decided that a VFD is right approach for me, and went with a GS20 series from Automation Direct. It seems like a moderately priced, richly featured, well-supported sweet spot. I got a 3hp drive; I suspect that wasn’t too important but it wasn’t a lot more expensive than the 2hp drive. 

When I got the mill, it was fairly filthy, so I disassembled it completely, including the head. It’s now back together and the VFD is running the motor, but without any external controls yet. I do have the motor speed selector connected to the VFD, to select the appropriate parameters for high and low speed operation. It needs a braking resistor, to run in high speed especially, where it’s getting some over-current faults, but I have a resistor arriving tomorrow.


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## rabler (Apr 30, 2021)

I have both VFDs on two machines, and rotary phase converter for two others.  My general rule of thumb is that a VFD is a win for 3HP or less.  Above that and the RPCs are more attractive from a cost perspective.


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## westerner (Apr 30, 2021)

BladesIIB said:


> Lots of support on this forum if you choose the VFD route.





jwmelvin said:


> I decided that a VFD is right approach for me, and went with a GS20 series from Automation Direct. It seems like a moderately priced, richly featured, well-supported sweet spot.


Yup. I did exactly this on my 1 hp Millright. My 58 year old mechanic brain made sense of the programming with a little help from my friends.
Dead quiet, fits in the box where the previous hardware was, and is trouble free. Less than $200.


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## Aukai (Apr 30, 2021)

My 8" RT is difficult to lug around, 14" would be a gut buster....


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## mksj (Apr 30, 2021)

On a belt drive single machine, a VFD is probably the easiest and the variable speed will come in very handy. Installing a VFD on a mill is very straight forward. WIre the VFD to single phase power, wire the VFD motor outputs directly to the motor, replace the current direction switch with a simple FOR-OFF-REV switch with two contact blocks (used to switch the VFD low voltage direction inputs), add a speed pot or use the one on the VFD. QED. It will also be quite a bit less expensive then a RPC unless you put together something yourself. Mount the VFD away from any chips, some people will mount them in the base.

The Teco L510 is a basic VFD, manual is very readable, has a warranty and also tech support. Otherwise you can ask questions in this forum and get your questions addressed.








						VFD, 3hp, 230V, Single Phase Input, IP20, Medium D
					

VFD, 3hp, 230V, Single Phase Input, IP20, Medium Duty, Speed Potentiometer, Easy to Program, Compact, 150% Overload, V/F Control, Auto-Torque Boost or Sensorless Vector, 3 Phase Output




					www.wolfautomation.com
				












						Selector Switch, Ø22mm, 3-Position, 2NO, Maintaine
					

Selector Switch, Ø22mm, 3-Position, 2NO, Maintained, Non-Illuminated Knob, NEMA 4X, IP65




					www.wolfautomation.com
				



or





						Potentiometer: 5k ohm, 22mm, black (PN# ECX2300-5K) | AutomationDirect
					

ECX2300-5K - Potentiometer, 5k ohm, 22mm, black. Legend plate ECX2640 purchased separately.



					www.automationdirect.com
				








						Legend Plate: "0 to 100 scale" (PN# ECX2640) | AutomationDirect
					

ECX2640 - Legend plate, plastic, black field, black background, white engraved text, legend plate marking



					www.automationdirect.com
				





			https://www.automationdirect.com/adc/shopping/catalog/pushbuttons_-z-_switches_-z-_indicators/22mm_metal/selector_switches_illuminated_-a-_non-illuminated/non-illuminated/gcx1320-22
		



			https://www.automationdirect.com/adc/shopping/catalog/pushbuttons_-z-_switches_-z-_indicators/22mm_plastic/22mm_pushbutton_accessories/legend_plates/ecx1670-b19


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## jwmelvin (May 1, 2021)

Here’s the GS20 if you’re interested: https://www.automationdirect.com/ad...quency_drives_(vfd)/general_purpose/gs21-22p0


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## Gman45acp (May 1, 2021)

mksj said:


> On a belt drive single machine, a VFD is probably the easiest and the variable speed will come in very handy. Installing a VFD on a mill is very straight forward. WIre the VFD to single phase power, wire the VFD motor outputs directly to the motor, replace the current direction switch with a simple FOR-OFF-REV switch with two contact blocks (used to switch the VFD low voltage direction inputs), add a speed pot or use the one on the VFD. QED. It will also be quite a bit less expensive then a RPC unless you put together something yourself. Mount the VFD away from any chips, some people will mount them in the base.
> 
> The Teco L510 is a basic VFD, manual is very readable, has a warranty and also tech support. Otherwise you can ask questions in this forum and get your questions addressed.
> 
> ...


The mill has a forward reserve switch that the previous owner remarked to Hi   Low.    The person I bought it from did a estate buy out and said he sold a vfd with a lathe.    He said there was no rotary phase conversion in all the stuff he got.  So this mill probably was ran on a vfd.


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## Gman45acp (May 1, 2021)

So could this switch be used for forward and reverse ( I believe it can) and the just get the vfd and use this switch with it?


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## pacifica (May 1, 2021)

Gman45acp said:


> So could this switch be used for forward and reverse ( I believe it can) and the just get the vfd and use this switch with it?


That's not a great idea, use the forward reverse built in  the VFD.


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## ttabbal (May 1, 2021)

Gman45acp said:


> So could this switch be used for forward and reverse ( I believe it can) and the just get the vfd and use this switch with it?



Yes, but not the way it is wired now. VFDs can't have switches and such in between the VFD and the motor. Having one can result in blowing the transistors when switching. 

What you can do is connect the switch to the low voltage control inputs on the VFD. I found it simpler to just use a switch more designed for that.


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## mksj (May 1, 2021)

If it is a 2 speed motor, you do not use both the low and high rpm settings, look at the motor name plate and wire it to use the setting with the most Hp. You then use the VFD to control the speed, not the motor windings. High voltage switches, in particular those that have been used getting arching and will give poor intermittent connections with the low voltage signaling used in VFD's. A replacement 3 way switch as I outlined are inexpensive and will work much better. The GS20 VFD is also a good alternative, they all work pretty much the same at this level.


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## Winegrower (May 1, 2021)

I have added a VFD to a wood lathe and use a phase converter to power my Bridgeport clone, the Takisawa lathe, and the Kalamazoo horizontal saw.   A friend has a rotary phase converter for about the same set of machines.

The VFD is ok, but took a bunch of fiddling around (I am an EE so not hard or confusing, but another buddy really could not have done his by himself) and really did not make much improvement over how the lathe would have operated on a direct 3 phase circuit.  It has a Reeves drive for variable speed as factory standard.

The rotary converter can be heard all over his house.   I recommend using the years you have left to spend an hour or two wiring up a Phase-a-Matic and start making chips.

The mill has a two speed with reverse motor, with backgear, and 4 positions on the step pulley.   I almost never change the belt position, since I get 4 speeds from 80 to 1320 or so, seems to cover my needs.

I have never come close to noticing any power loss.  I can make all the smoke I need.


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## jwmelvin (May 1, 2021)

I just added a braking resistor to my GS20 (3hp). I used a 68 Ohm, 500W resistor. There are a few more available at a low price if anyone is using a similar drive and needs a braking resistor: https://www.newark.com/cgs-te-connectivity/tjt50068rj/res-wirewound-68r-500w-wire-lead/dp/69AC5221

It’s an amazing improvement. I really like it so far. 

I have the original high/low switch in place, and used some extra contacts on it to feed back to the GS20 to change motor parameters in the drive. It seems to work well in my limited testing. The mill finally has new felt wipers and the lube system seems to be pumping so I’m basically ready to try the machine out. 





I’ll try to shoot a quick video. I have deceleration time set at 1.0 sec.

Here’s a video:


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## Gman45acp (May 1, 2021)

mksj said:


> On a belt drive single machine, a VFD is probably the easiest and the variable speed will come in very handy. Installing a VFD on a mill is very straight forward. WIre the VFD to single phase power, wire the VFD motor outputs directly to the motor, replace the current direction switch with a simple FOR-OFF-REV switch with two contact blocks (used to switch the VFD low voltage direction inputs), add a speed pot or use the one on the VFD. QED. It will also be quite a bit less expensive then a RPC unless you put together something yourself. Mount the VFD away from any chips, some people will mount them in the base.
> 
> The Teco L510 is a basic VFD, manual is very readable, has a warranty and also tech support. Otherwise you can ask questions in this forum and get your questions addressed.
> 
> ...


Just to be clear, I order the for parts above and then should have everything needed to get it wired up, be able to control rpm and forward and reverse.


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