Warco WM250

... My machine is the 2012 version bought at Harrogate exhibition.

Geo.

Neil, I do not do complex these days. I have ordered the new motor and VFD today I have managed to get a 1hp in 71 frame size, the 80 was just to big. I have put the old motor back in so that I could take photo's. Jason you are right that is exactly the set up I have. I have a suspicion that the tooth belt may be a bastard size. I don't think Warco have any as they had memory failure over the fact that the WM250 of that time were even fitted with a tooth belt.

No more workshop today as it is rather cold and I need to move the lathe in order to get access to the back. Will need help with that as I have a slipped disc at the moment.

Dusty I don't think you're on my list of existing contributors

Drop and email to [email protected] and I'll send you the guidance for authors tohelp you get off to a good start.

Thanks

Neil

Dusty, the belt might have a designation on it..... Something like 7M 820....

These are pretty handy folk.... http://industrialbeltdrives.com/quote/v-belts/polyflex-jb/

Beeline engineering in Milton Keynes.

They supplied me with belts for my Chester 9 x 20 and for my SPG 2129 lathe....I collect from them when I visit my daughter in Northampton.

I have a transmision specialist near me but nowhere near as good as Beeline and they are cheaper too...

Edited By John Rudd on 10/02/2017 16:59:00

Whilst waiting for my new motor to arrive I have been stripping some of the parts from my lathe ready for modification. I spoke earlier about the tacho, you were right John it all seems to run from the filter, if my understanding is right I only need to connect that to power and its all systems go. If I use the existing NVR in the power lead can I connect the filter power to the out side as well as the VFD or is there a problem with that?

Dusty,

In terms of wiring the vfd, remove the Live and Neutral wires that went to the L1 & L2 terminals on the old speed control board. These two wires need to go to the Live and Neutral In on the vfd. You may need to extend the wires.

I cannot be specific about the terminals as I dont know which inverter you bought.

The speed control pot mounted in the front of the lathe will need wiring into the vfd too, the motor wiring from the motor terminals needs to go to the inverter motor terminals..

If not already programmed for an external analog input, the inverter will need programming for this and for any switch inputs you use for start/stop fwd/rev etc....

If not already fitted, you should add a fuse for the vfd too....( thats my opinion, other folk may have differing ideas....speak up! )

Edited By John Rudd on 14/02/2017 09:45:37

I agree with John. We will need to see the manual on the VFD and will need to tell us what controls you want as well as the speed control. (Forward / reverse switch, safety interlocks etc. ) I also fitted a three position biased centre off toggle switch for jogging the lathe in forward and reverse. I initially just used the preset jog speed on the VFD but later added a seperate jog speed control. This speed control had a maximum setting of about 33% of the normal maximum speed. I find this usefull for screwcutting.

Les.

I can relay my experience with a warco 280 if that would help. I was unable to juice the tacho board on the back of the display unit so that it would run of its own accord. I was unhappy about running mains voltage wires into the front of the headstock just for the sake of the tacho, so I butchered a phone charger and wired it into the fused supply in the control box, then ran the 5V cable through and patched it in to the power supply board after some testing to work out how far back up the circuit I needed to put it to get it all working.

You can of course use the VFD display to show speed, but I preferred the VFD to be properly enclosed in the control box, and the tacho to come from measuring the actual spindle speed, in case I alter the pulleys.

As for the motor fitment, the 280 has threaded holes in the bed, revealed when the rear control box is removed, the 250 may well be the same?

So I cut off the lower half of the control box, and mounted the VFD in the upper half.

The threaded holes were at the spacing for an 80 frame motor, I chose the higher power option at 1.1Kw, and just mounted it on threaded bar and nuts, which allows for tensioning the belt (if a little rudimentary).

I then used nutlink belt and a pair of taperlock pulleys to finish the job, obviously they go straight on the motor, but happily the 280 spindle is a simple M40 thread so the old pulley was spun off and easily replaced with a taperlock one.

The whole thing was so easy that I was able to get the lathe going without needing a working lathe to make parts, obviously I could refine the setup a little now, but it works well enough as it is.

Cabinet Enforcer, can I ask what spindle speeds you are able to get with that setup and are they pullys two sizes giving you a high and low range? Also is it a 2 pole or 4 pole motor.

I will have to have a look in the back of my 280 to see if teh bed is tapped.

Thanks, Jason

Jason,

When I swapped out the motor on my SPG 2129 ( 290 equivalent ) the new motor was mounted on a swivelling bracket attached to the bed to permit belt tensioning. The bracket carried the original brushed motor and had the right hole spacing for an 80 frame motor...making changeout easy....

I swapped for a 2 pole motor and ran the vfd at 75 hz to give me the same spindle speeds as before...I just bored out the motor pulley to fit the motor shaft.....QED....

Thanks John, so in the low range to get 50rpm spindle speed the motor would be running at about 220rpm which would need 4hz?

Ahhh, I fibbed...fMax is set to 70hz not 75.....

At 5hz the spindle is doing 75 rpm.....the motor is turning at whatever speed......I'd need to check other parameters on the vfd which is a bit awkward tucked away in the box....

Don't go to any trouble on my account John, I just was not sure how low the motors would run.

Funny enough over the last couple of years my DC motor seems to have speeded up, where as I used to get 45-950 in low range I now seem to get 70-1050 on a warm day, touch less on a cold one..

Jason - If you want to slow it down a bit there is amongst the mini pots on the speed control board, one which if backed of - anti clock - will do the job. If memory serves it's the bottom left when viewed with the heatsink at the top - but double check I'm right before you do it!

Rik (John will probably correct me if I'm wrong)

Hi Jason,
I wonder if the magnets in the motor are becoming weaker which would cause the motor to run faster on the same voltage ?

Les.

Edited By Les Jones 1 on 14/02/2017 15:45:10

Quite possible Les, especially if the motor has been worked hard and got warm ( hot? ) I've no idea what the Curie point is of the magnetic material that is used in these Chinese motors.....One of the reasons to use an extra fan to aid cooling, not just to keep the comm cool, but also the magnets....So imagine if the casing of the motor is quite warm, how hot are the magnets?

I did notice the body of my mini mill motor was rather warm ( hot ) running flat out with a 2mm carbide cutter in cutting aluminium and I wasn' t pushing it either, but could smell 'that electrical warm smell' so I added a small fan to the nde of the motor to help cool things down.....( didnt help coz the motor is toast now!.....think it needs new brushes I hope....lots of sparks around the comm at high speeds....      )

Edited By John Rudd on 14/02/2017 16:17:43

Edited By John Rudd on 14/02/2017 16:26:32

The pulleys are doubles as the belt calcs for the full 1.1Kw say there should be two belts, nothing so fancy as two sizes Of course the pulleys don't line up perfectly so two belts can't be used, if I had a working lathe I could machine a new spacer for the spindle, maybe I will get a round tuit now I remeber it needs doing.

Pulleys are 71mm and 106mm, this gives speeds from 60 to 2000. There isn't huge amounts of torque left at 60 though, and I suspect it could do with both belts on at lower speeds too as slip can start to be an issue if you push it hard. Motor is 4-pole.

In retrospect I would not have chosen these sizes and now would probably go with a 60mm or 56mm and a 125mm to get the low end more usable, and have an alternate set in the cupboard with maybe a 2500 top end.

Getting the pulley ratio yet lower would require an intermediate pulley, or perhaps looking at alternate belt/pulley types, this wasn't possible when I did mine as it was the first lathe I bought and it was broken when I bought it.

Hopefully my new motor and other gubbins will arrive tomorrow. I will however spend most of the day at Hospital arranging for my cataract operation. I hope that when done I will be able to see clearly again. I spent today taking the rest of the headstock end apart. Those naughty orientals do hide screws in funny places that are very difficult to get at. I did discover that the WM250 does not have tapped holes in the bed. A fact that I am rather glad of, having ordered a face mount motor. It looks like it may be the weekend before I am able to make any progress, due to other (family) commitments. Once I have the VFD and a wiring diagram for it I will hopefully come back for more advice.

Well the motor and VFD have arrived. I have been machining the motor mount in order that I can fit the motor to it. I am afraid that the boss stopped me as it was making too much noise, which I had to agree. I think I will screw it to a piece of MDF in an effort to stop the vibrations. For those interested the motor is a TEC, 71 frame 1hp with face mount. If the bed had been tapped then a foot mount would have worked. The VFD is an Invertek optidrive. Over the next few days I will hopefully cut and carve the sheet metal of the lathe to accept the motor. Then the fun will start connecting everything up.