Motor options - wood fast lathe

[Peter57]

So,

Tony ( N.C. Archer) sold me an old woodfast lathe that requires some restoration and reassembly. One question I have is whether it's better to add a VFD and keep the original 1/2 hp 415V motor or buy a new 240V (1hp) motor and use something like this unit from Jaycar as a speed controller.

https://www.jaycar.com.au/240v-10a-deluxe-motor-speed-controller-kit/p/KC5478

Any advice gratefully accepted.

cheers,
Peter

[BobL]

The Jcar units are a kludge and won't ever provide full power.

Presumably you are referring to a 240V Single Phase to 240V 3 Phase VFD.

Keeping the 1/2HP 415V 3 Phase motor is an option provided it is able to be reconfigured into a 240V 3 phase motor.
Usually these motors are configured as 415V STAR (Y) motors and may or may not be able to be configured into 240V DELTA (∆)

If you do not do this it will run but at most will be a 1/4Hp motor.

Even if you can convert it to a 240V DELTA (∆) it will not give full power across the speed range.
From zero to 50 Hz it will deliver proportionate power.
50Hz will be 1/2HP, 25Hz will be 1/4HP 12.5Hz will be 1/8HP.
From 50 to about 100Hx it will give full power and then it will start to drop off above that.

To help get around this a more powerful motor is used (usually doubt the HP of the original motor)

[bueller]

Those Jaycar kits can't be used with an induction motor so they're out. And the original 3 phase motor will probably be too underpowered once running on a VFD. Probably looking at a bigger 3 phase motor and VFD.

[Bohdan]

The Jaycar kit can only slow a motor down. As it slows it will also loose power and torque so on the larger diameter cleanups when you need low speed you will also have low torque and I don't think that that is desirable.

The VFD on the other hand can be used to speed up the motor, you then put the belt on a small motor pulley to bring the speed down to the required value, this will increase the torque and you can the lower the speed via the VFD.

Remember that when you dial the VFD to below 50Hz you loose power and torque.

[powderpost]

I think the best option is to fit a Woodfast EVS unit. Yes, they are expensive but very reliable. I have been using one for about 15 years and very impressed.

Jim

[hughie]

I rebuilt a Woodfast 400 1987 model and replaced the 1/5hp with a 1hp 3 phase and it worked well. In your case you will have to change the switch gear as it has a 3 phase coil and as stated dont bother with Jaycar I used a a Lenze motor controller that I had on hand. Alternately look on ebay this where I bought my current VSD.
Is it worth it? Yes, most definitely, I kept the stepped pulleys to offset the torque loss at low speeds and also fitted a pot [10 turn 100k ] to vary the speed . The ten turn will cost you a little more but will give very fine speed control.

It was posted on the forum but with subsequent software up grade the images have been stripped away.

[NeilS]

I think the best option is to fit a Woodfast EVS unit. Yes, they are expensive but very reliable. I have been using one for about 15 years and very impressed.

Jim
Ditto.

I'm not saying that others aren't as good, but none of my Woodfast EVSs have ever missed a beat and they have all had lots of use.



Stay sharp!

Neil

[Mobyturns]

I agree with Jim (PowderPost) that the M910 Woodfast EVS retro fit is a great option, but relatively expensive. If the old woodfast lathe is in good condition it will be well worth the expense. I have the first M910 EVS retrofit kit fitted to my 1992 Woodfast M908 lathe after I pestered Bronte Edwards to supply it. Its super smooth and reliable. Definitely the best of both worlds now, Aussie cast iron and EVS.