Adding VFD to Webb/Whacheon/Mori Seiki?

Anybody have a procedure/write up on adding a VFD to a Webb/Whacheon/Mori Seiki?
I have a Webb (Whacheon) 17”Gx40” with a 5HP 3ph spindle motor.
I’d like to integrate a VFD to drive the spindle motor and a separate VFD for the coolant pump.

Suggestions on integrating the forward/reverse lever and the brake pedal?

Contactor wiring diagrams?

I have a clone to your machine although mine was factory with a 7.5 hp motor. To reduce the cost of the VFD I swapped the motor to a 5 hp and did the VFD install using all the factory buttons and apron lever.

I junked all the electrical components except the mag for "control power" and the main mags that were used for FWD and REV of the lathe. In my case the mag coils were 120 volt which I powered separately from a standard wall mount DCO (outlet).

The frequency drive is wired directly to the motor while all lathe factory buttons and lever function now control the mags that previously controlled the motor, but now they switch logic functions on the buss of the drive to allow FWD,REV,JOG. The mags contacts now act as simple switch closures for the logic buss.

You don't need to rewire the lathe panel or snake new wires from the apron lever, you merely ID those existing wires inside the enclosure and wire them to the appropriate mag coils which switch drive function.

For the coolant pump, I dumped the 3 phase unit and installed a smaller single phase (120v) pump and again, used the coolant switch on the control panel.

Is this what you are trying to achieve?

Stuart

atomarc said:

I have a clone to your machine although mine was factory with a 7.5 hp motor. To reduce the cost of the VFD I swapped the motor to a 5 hp and did the VFD install using all the factory buttons and apron lever.

I junked all the electrical components except the mag for "control power" and the main mags that were used for FWD and REV of the lathe. In my case the mag coils were 120 volt which I powered separately from a standard wall mount DCO (outlet).

The frequency drive is wired directly to the motor while all lathe factory buttons and lever function now control the mags that previously controlled the motor, but now they switch logic functions on the buss of the drive to allow FWD,REV,JOG. The mags contacts now act as simple switch closures for the logic buss.

You don't need to rewire the lathe panel or snake new wires from the apron lever, you merely ID those existing wires inside the enclosure and wire them to the appropriate mag coils which switch drive function.

For the coolant pump, I dumped the 3 phase unit and installed a smaller single phase (120v) pump and again, used the coolant switch on the control panel.

Is this what you are trying to achieve?

Stuart

Click to expand...

Yessir!
Exactly so!
Thanks for your response!

atomarc said:

I have a clone to your machine although mine was factory with a 7.5 hp motor. To reduce the cost of the VFD I swapped the motor to a 5 hp and did the VFD install using all the factory buttons and apron lever.

Stuart

Click to expand...

What VFD did you use?
Did you go 220V-240V or 440-480V?

rpseguin said:

What VFD did you use?
Did you go 220V-240V or 440-480V?

Click to expand...

I did this retrofit quite a few years ago and because my available power was only 240v-single phase, I re-powered the lathe from 7.5 hp to 5 hp and used a new Hitachi 10 hp inverter. (X200-075 LFU) The drive size had to be doubled as it was being powered by single phase and a 10 hp unit was quite a bit cheaper than a 15 hp drive.

At the time I purchased the drive it was $680 dollars, and that was probably 10 years ago.

Stuart

If you go with a 3 phase VFD, the derating varies a bit and you should run a DC choke. So something like the WJ200-075LF (7.5 kW) these days, the WJ200-055LF (5.5 kW)would be marginal but I have seen people use it for 5 Hp motors. Depends on the motor and current draw. Another option is the Yaskawa V1000, CIMR-VUBA0018FAA, 5HP, 1-Phase, 200-240V (Input) which I have used in a few lathes. They run about the same as the WJ200-075LF, I use their 3 phase 5.5kW in my 3 Hp lathe derated for single phase. In either case, a DC choke is recommended.
Yaskawa CIMR-VUBA0018FAA, 5 HP, 200-240V, VFD

So a few things on the lathe controls and the foot brake, you should not directly connect the spindle direction switches directly to the VFD inputs to prevent accidental restart say if you release the E-Stop switch. I typically use a latching power relay and separate forward/reverse run relays, the system is wired so there are different interlocks. Jog Forward is a specific designated input on the V1000, the WJ200 it takes two separate inputs where one sets the frequency to jog and the other needs to activate the spindle direction (requires two separate switch blocks). I setup the JOG circuit so it can only work when the forward or reverse relay is not activated. The relays are run off of a separate 24V power supply.

I use a separate 2 pole relay for the foot brake which cuts power to the latching power relay and also sends a free wheel command (coast to stop) to the VFD. This can also be done with a dual pole foot brake switch, but a relay is much cheaper. The power relay is reset when the spindle switches passes through the stop position.

A single phase coolant pump is cheaper than a VFD for the most part and easier to install, although KB Electronics has some inexpensive small VFDs (KBVF-23) that I have used for similar purposes.