Thread: Found a lathe with a bum motor - motor replacement viability?

Originally Posted by Pyrex

Ah, that is a very nice lathe! I hope mine will look that nice one day.

So, an update -

I did end up purchasing the lathe for a great price. As best as I can tell, the lathe is a 1967 Clausing Colchester 13x36" Master MK 1.5. The owner destroyed the original motor and tossed it. With that being the case, it would seem the most economical and easiest solution would be to install a 3HP single phase motor at 1800rpm. My machine was a two-speed variant, with 1800hp being the higher of the two RPM inputs, so that would give me the greatest rpm spectrum.

Pyrex,

I have a 1962 Clausing Colchester 13 x 36 round head. It has the original motor which is three phase, two speed, 3hp, 1800rpm and 1.5 hp 900 rpm.

Mine has a very complicated motor control system. If it is like mine make sure you understand it. If you google my lathe you will find the manual that includes the wiring diagram of the controller.

When I got it VFD's weren't available. I wired up an auto-transformer phase converter to use single phase power. Later i wanted slower speeds and added a 3hp VFD. Now that I have the VFD I almost exclusively use the VFD with the lathe in HI (3hp,1800rpm) and control the speed with the VFD. It is wired to use all the original lathe controls.

IMO a 3hp 1800 rpm 3 phase motor and a VFD should work fine if your lathe is as similar to mine as I think it is.

Good Luck,
Joe

Originally Posted by mksj

So a few suggestions should you decide to go the VFD route. First, you would only go with a single speed motor, there is nothing to be gained with a 2 speed motor in this case. In fact, even if you didn't go with a VFD, I would probably go with a single speed motor. My brief review of this model was the 2 speed motor gave you very low speeds, you could get by with a single speed. I have also had a disproportionate amount of problems with 2 speed motors when using a VFD (with the exception of constant Hp motors).

If you are installing a VFD on a lathe, it is a bit more complex as there are a lot of safety issues that need to be incorporated into the design. Also this particular lathe is a bit different as to the operation with the clutch, that might work in your favor as to disengage the drive but leaves the motor running. I would need to see the schematic/manual to give any specific suggestions. It is all doable, but not easy like on a mill. You pretty much have to do all the electrics. If the forward/reverse contactors were replaced I have stripped out the high voltage connections to the contactors and used one set of poles on each contactor to trigger the FOR/REV inputs on the VFD.

The Fuji drive you mentioned is a 3 phase input 5 Hp, could be used in a derated mode but would need a DC choke. I would stick with a single phase input 3 Hp 230VAC VFD (FRN0012C2S-7U). For Fuji I would check Wolf Automation, seems to be a line that they are using. They do support an external braking resistor and are pretty full featured.
FRN0012C2S-7U | Fuji Electric | AC Drives
FRN0020C2S-2U | Fuji Electric | AC Drives

I often used the Hitachi WJ-200-022SF (3Hp single phase input),
Teco Westinghouse E510-203-H-U, Yaskawa V1000, etc. All good VFDs, if you have experience with Fuji then go with that if you choose to do a VFD.

Whoops, can't believe I selected a 3-phase input model, definitely didn't mean to do that. Thanks for all the great info. I'm not afraid of getting a little dirty to get the machine working the way I need it to. Using the higher of the two speeds makes sense, that was going to be my intention. Honestly, the wiring on my other Fuji's couldn't have been simplier, so I'm indifferent as to which I go with. It does seem like a lot of forum members prefer the Westinghouse and Yaskawa.

You mentioned the Hitachi WJ-200-022SF, which is a 3HP with a current rating of 11 it looks like. My lathe is a 3HP 7.8 amp motor on the high setting, would this be adequate? It's been years since I sized a VFD, but I thought you typically overrated them.

Originally Posted by Joe H

Pyrex,

I have a 1962 Clausing Colchester 13 x 36 round head. It has the original motor which is three phase, two speed, 3hp, 1800rpm and 1.5 hp 900 rpm.

Mine has a very complicated motor control system. If it is like mine make sure you understand it. If you google my lathe you will find the manual that includes the wiring diagram of the controller.

When I got it VFD's weren't available. I wired up an auto-transformer phase converter to use single phase power. Later i wanted slower speeds and added a 3hp VFD. Now that I have the VFD I almost exclusively use the VFD with the lathe in HI (3hp,1800rpm) and control the speed with the VFD. It is wired to use all the original lathe controls.

IMO a 3hp 1800 rpm 3 phase motor and a VFD should work fine if your lathe is as similar to mine as I think it is.

Good Luck,
Joe

That's great to hear Joe. Your reality is my goal, then. I would like to keep all of the original controls if at all possible. You wouldn't happen to have any wiring diagrams you made when you did your conversion that might help me, would you? So, you leave the lathe in high speed on the mechanical side, and control all of the RPM with your VFD? I had been wondering about that doing that, as it seemed like the most logical solution. I'm assuming the highest speed gearing is a 1:1 throughput? Are you using your lathe brake or a braking resistor to stop your spindle? I'm curious. also, do you have any photos of how you have your VFD and controls mounted? Also, which VFD did you go with?

I use the Hitachi WJ200 VFDs quite a bit at this size level, they are very durable and have a good range of programming abilities. I would recommend that or the Teco E510 (the L510 which is less is a poor choice for a lathe). Have not used the Fuji, but the single phase 3Hp VFD should also work OK. You size the VFD to the motor kW/amps, you do not need to oversize the VFD unless you plan to move to a larger motor or derating a 3 phase VFD for use on single phase. I have lathe programming parameter files for the WJ200 if you need something as a starting point.

What I gather from the the brochure on the Clausing Colchester 13 x 36 is that the 2 speed version was a 3Hp/1.5Hp 3 phase motor 1800/900 RPM motor. The machine speed range was 39-1500 RPM. So using a single speed 1800 RPM motor would be optimum (with or W/O a VFD), and on a VFD you have the same Hp at 30 Hz as the 2 speed. They did make single speed motor versions, and evidently the single phase versions the motors did not hold up well. I would go with a inverter rated motor, TEFC or TENV. I often using the Marathon Balck Max or Blue Max motors, Baldor or Lincoln. I happen to have a new Lincoln inverter/vector TENV motor that I was going to use on a lathe build that is sitting in my shop. These motor require a VFD, they are killer for use in lathes.

There are various mechanical (and electronic motor brake) braking systems depending on the lathe version, but you also can use the VFD electronic braking. I set up my lathe systems so the braking rate can be selected for 1 stage (1-1.5) seconds or 2 stage (3 seconds) and if there is a manual brake the VFD is sent a freewheel (no VFD electronic braking) when engaged. With a mechanical brake you also need a means to kill the VFD run command during and after the mechanical brake is pressed otherwise the motor would restart. This usually involves a latching relay design.

As I previously indicated, the simplest design/install is to run a VFD off of the stock controls is to replace the stock forward/reverse contactor (I use the mini contactors), strip the high voltage wiring and use one set of the contacts for the VFD FOR/RUN run commands. This retains all the stock switch gear and functions. The contactors need to be replaced because the burnt contact points on old contactors often will not conduct the low level VFD signaling which is 24VDC at a few mA. I typically build complete new systems, but for inexperienced individuals who want to run a VFD this method is doable. There are a lot of variations, and it is machine specific.

Once you get the lathe set it up and check it carefully. As suggested make certain you understand the electrics. I've bought a lot of machine tools, including lathes, with supposedly "blown" motors only to find out there was a bad contactor, or a bad interlock, or whatever. Makes a lot more sense. Seriously how would you "blow up" a motor on a manual lathe? Pretty hard to stall a lathe the tooling always fails first. Not that it's impossible someone could run the carriage into the chuck and jam it hard but even then to smoke the motor they'd have to stand there and watch it burn up. The motor is usually in the bottom of the cabinet so if the lathe stood in two feet of water then I could see it otherwise look first for other problems.

Originally Posted by adh2000

Once you get the lathe set it up and check it carefully. As suggested make certain you understand the electrics. I've bought a lot of machine tools, including lathes, with supposedly "blown" motors only to find out there was a bad contactor, or a bad interlock, or whatever. Makes a lot more sense. Seriously how would you "blow up" a motor on a manual lathe? Pretty hard to stall a lathe the tooling always fails first. Not that it's impossible someone could run the carriage into the chuck and jam it hard but even then to smoke the motor they'd have to stand there and watch it burn up. The motor is usually in the bottom of the cabinet so if the lathe stood in two feet of water then I could see it otherwise look first for other problems.

Well, in this case to blow up a motor you wire it into single phase and flip a switch. There's no doubt it can't be fixed seeing as it was tossed in a dumpster over a year ago

Originally Posted by mksj

I use the Hitachi WJ200 VFDs quite a bit at this size level, they are very durable and have a good range of programming abilities. I would recommend that or the Teco E510 (the L510 which is less is a poor choice for a lathe). Have not used the Fuji, but the single phase 3Hp VFD should also work OK. You size the VFD to the motor kW/amps, you do not need to oversize the VFD unless you plan to move to a larger motor or derating a 3 phase VFD for use on single phase. I have lathe programming parameter files for the WJ200 if you need something as a starting point.

What I gather from the the brochure on the Clausing Colchester 13 x 36 is that the 2 speed version was a 3Hp/1.5Hp 3 phase motor 1800/900 RPM motor. The machine speed range was 39-1500 RPM. So using a single speed 1800 RPM motor would be optimum (with or W/O a VFD), and on a VFD you have the same Hp at 30 Hz as the 2 speed. They did make single speed motor versions, and evidently the single phase versions the motors did not hold up well. I would go with a inverter rated motor, TEFC or TENV. I often using the Marathon Balck Max or Blue Max motors, Baldor or Lincoln. I happen to have a new Lincoln inverter/vector TENV motor that I was going to use on a lathe build that is sitting in my shop. These motor require a VFD, they are killer for use in lathes.

There are various mechanical (and electronic motor brake) braking systems depending on the lathe version, but you also can use the VFD electronic braking. I set up my lathe systems so the braking rate can be selected for 1 stage (1-1.5) seconds or 2 stage (3 seconds) and if there is a manual brake the VFD is sent a freewheel (no VFD electronic braking) when engaged. With a mechanical brake you also need a means to kill the VFD run command during and after the mechanical brake is pressed otherwise the motor would restart. This usually involves a latching relay design.

As I previously indicated, the simplest design/install is to run a VFD off of the stock controls is to replace the stock forward/reverse contactor (I use the mini contactors), strip the high voltage wiring and use one set of the contacts for the VFD FOR/RUN run commands. This retains all the stock switch gear and functions. The contactors need to be replaced because the burnt contact points on old contactors often will not conduct the low level VFD signaling which is 24VDC at a few mA. I typically build complete new systems, but for inexperienced individuals who want to run a VFD this method is doable. There are a lot of variations, and it is machine specific.

Thanks for taking the time to explain all of this. You've been very helpful to me. As I mentioned before, I've installed VFD's, but only in fairly rudimentary applications. This will definitely be the most complex conversion I've done, but I feel confident I can handle the wiring.

Prepare yourself for a lot of questions.

I will be using an original two speed motor for this build, so no aftermarket motor. Based on what you've said, I get the feeling what I'm going to be doing is wiring the VFD into the high speed side of this motor, so it has full control over the entire spectrum, bypassing the low speed as (I assume) it isn't necessary since the VFD can essentially vary the frequency to achieve the same thing. On that note, is it also possible to wire the low speed lever into a VFD input to force a particular frequency, for instance 50% power to simulate the low speed in the factory configuration? Or, can the VFD switch to a separate set of outputs on the low side of the motor wiring to effectively use the low speed as it was intended?

As for the controls on the lathe, I'll need to track down their circuits and contacts which should be a quick date with my multimeter and wire those into the VFD's inputs. I don't yet understand how the inputs on a VFD work; but I assume there is an array of terminal blocks which initialize various features when a circuit is completed. Much like inputs on a CNC controller, or am I oversimplifying this?

Also, looking at the wiring diagram it appears the Hitachi WJ-200-022SF has braking resistor capability (it looks like I need an additional module of some kind). It looks like the FRS input essentially kills the output from the VFD and lets it free spin. I'm guessing this would be a little trickier since I can't imagine the brake engagement lever would have any electrical circuit or relay in it's original configuration. I would need to find some way to complete a circuit (mechanically - microswitch?) on that lever to engage the FRS input when the mechanical brake is engaged like you mentioned. I'm not sure what the condition of the mechanical brake on my lathe is, but worst case scenario I may need to revisit that.

You also mentioned removing all the high voltage wiring and the original contacts due to signal loss/degradation. I'm assuming you're talking about the main power wires to the motor itself? As for the other control wiring, are you only using the controls in the most simple sense - to complete a circuit for a VFD input? If that's the case it makes sense to just rewire everything for simplicity and sanity sake.

I'm not sure if I mentioned this earlier, but given the VFD can essentially run the motor at any frequency and speed, is there any reason to use the headstock gearing? I'm guessing because of the motor power and efficiency when it's geared down? Do you use your headstock gearing to get to the general RPM range and then the VFD for fine adjustments?

Pyrex,

I wired my lathe up 30 years ago. I don't have a wiring diagram. My lathe has a 2 speed reversing drum switch which controls the motor speed and direction, I do have the wiring diagram for the switch. The starter , the long red handle, feeds power to the controller then to the 6 wire motor.

I wired the vfd between the starter and the controller. Not exactly kosher but I checked with a engineer and found out there wouldn't be a problem as long as I wasn't switching under load. It's been working for 30 years in a hobby shop setting. The start lever turns on the lathe.

I wired a remote to control the lathe. The VFD i used is probably no longer available. It is 3hp, single phase input.

Joe

Thanks Joe. I ran across one of your older posts and got some more info from that which is useful. I have a question for you. Are you using the three phase coolant pump for your machine? If so, how did you configure that?

If using a 2 speed motor, wire it for maximum Hp, should be 1750 RPM/ 4 pole. Do not waste your time with trying to use both speeds. If the motor was a 2P/4P (3500/1750) such as on a mill, I wire it for 4P and overspeed to 120 Hz. You must direct wire the motor to the VFD inputs, do not run it through switch gear in this application. You do NOT need a thermal overload, fusing, etc. between the VFD and the motor as this is handled by the VFD. Input fusing/breaker is recommended on the input power side to the VFD. This varies based on the manufacturer and if a DC choke is used, on the 3 Hp WJ200 I use 30A CC fusing with fast blow Bussman fuses.

You do not need to mimic the original 2 speed controls, if you want a slower speed just turn down the speed pot. I mount the speed pot and a basic tachometer ($20) in a pod usually under a DRO or somewhere convenient. If you really must have another fixed speed, you can program an input to whatever speed you want. The VFD receives commands via low voltage (10, 12, 24VDC) low current (a few mA) inputs and the speed inputs (typically 0-10V). No rocket science here, but these inputs are susceptible to electrical noise interference, so keep them away from motor cable and do not mix this wiring with any other powered wiring in the lathe.

The WJ200 has inputs for a braking resistor, you do not need a module or anything fancy. I typically get mine from Mouser Electronics or Digi-Key instead of Fleabay. Resistor 47-75 ohm 300-500W.
https://www.digikey.com/products/en?...0TJT50047RJ%20

You need a microswitch or roler limit switch to send a freerun command if using a manual brake, it also needs to kill the run command. So you need a DPDT so one input sends the freerun command and the other kills a latching run/power relay. The power/run relay is usually 4P powered by a separate 24V source, it breaks the connection to the for/rev inputs when open, it latches close when the spindle switch is in the stop position. Just one variant, I also use two 2P relays in a basic configuration. It is possible with the WJ200 to have it self power the relays since it's input power supply is 24VDC 100mA. You need to know what you are doing so you do not damage the VFD inputs.

I am not sure if your lathe uses contactors, so first figure out what you have and how it is wired, and then you design a control system that works around your machine. DO not be fixated on using the original controls.

If equipped with a mechanical brake, I would inspect it, as the brake liner can wear down and cause issues. If it has a mechanical brake then determine how it works and how you are going to use it. I also use mechanical brakes for locking the spindle say for manual tapping via the tailstock.

A VFD cannot run a motor at any frequency and have usable power. Below the base speed (60 Hz) the Hp decreases in a linear fashion and the torque may be flat to a specified Hz, you loose the mechanical advantage of the gearbox, so you have no power at say 10Hz. Above the base speed the torque declines so you have more difficulty taking deep cuts. Most factory VFDs lathes in this size are 2 speed manual gearbox, so something like 50-400 RPM and 400-2000 RPM. A VFD is NOT a substitute for a gearbox, just gives you a range of usable speeds that can be adjusted on the fly. A reasonable speed range is something like 20-90Hz, but is dependent on the motor and drive ratios. I use VFD/inverter motors on lathes and run them from 20-120Hz and use a smaller motor pulley so the maximum spindle speed is at 120Hz in high gear.

I would read the VFD manual and familiarize yourself with what what others have done/recommended.

You typically do not run flood coolant on a manual lathe of this size unless you are doing exotic metals, I would skip the coolant pump, otherwise a single phase replacement is around $100. Most people using coolant on a manual lathe go with a mist or droplet type of system.

Thanks for taking the time to write all of that out. Okay, sounds like we're both on the same page, then. I've attached a modified diagram as to where (I'm assuming) Joe wired in his VFD, based on his prior posts. I just want to make sure I'm understanding the most basic step.




Looking at the above diagram, Can I wire the VFD as indicated, or do I need to wire it before the magnetic starter? Based on what you said above I assume I can bypass the magnetic starter and wire as indicated. Downstream, if I removed the T1/T2/T3 wires to the motor, it should disable the low speed lever all together, and only energize the high speed lever. My only concern is do these motors need the low speed circuit energized to fuction in high as well? I don't know enough about two-speed 3-phase motors to answer that. Obviously, additional inputs will be required for the braking resistor and additional controls.

My last question is what would happen if I wired the VFD into the coolant pump as well? I assume the coolant pump motor frequency would be tied to the main driver motor?

Originally Posted by Pyrex

Thanks Joe. I ran across one of your older posts and got some more info from that which is useful. I have a question for you. Are you using the three phase coolant pump for your machine? If so, how did you configure that?

Pyrex,

my lathe does not have a coolant pump.

If you are using a single speed motor with a vfd you don't need the speed/reversing controller at all. Just wire the vfd directly to the motor. The vfd will provide speed control and reversing.

Joe

Originally Posted by Joe H

Pyrex,

my lathe does not have a coolant pump.

If you are using a single speed motor with a vfd you don't need the speed/reversing controller at all. Just wire the vfd directly to the motor. The vfd will provide speed control and reversing.

Joe

Thanks Joe, I'd like to retain the use of the controls if at all possible. Seems like a pretty easy thing to do, assuming my wiring is correct.

That will not work as drawn, you cannot use the current drum switch to turn on/off the motor nor reverse it as it will probably smoke your VFD. You do not use the magnetic starter/Heaters with a VFD as outlined.

The VFD is directly wired to the motor. If you want to play around with the current drum switch it can be used to activated the VFD low voltage inputs, although I see no reason to have a 1 and 2 speed with a speed pot. If you bump the drum switch or forget and leave it on when you power up the lathe it will start, also if you had an E-Stop and released it the machine will start, etc...

Do as you may, but it is a serious safety issue.

Thanks for the feedback. That's what I wanted to know. That was the other way I had it configured. Answered my question. I only plan on using the drum for controlling forward and reverse, not speeds.

You want all original controls, and the use of the 2 speed motor, stick to an rpc. Do you see now why an rpc is easier