Warco WM250

[Martin WParticipant @martinw]

Hi

Would it not have been better to remove the brushes first noting their orientation so that they can be refitted in their original position. In any case the curvature on the brush face/end must match the curvature of the commutator to maintain correct contact and prevent commutator damage.

Martin W

Edited By Martin W on 01/02/2017 16:27:35

[DustyParticipant @dusty]

Martin, they were removed first and I do know where they go and orientation for replacement, but thank you for the information.

[Les Jones 1Participant @lesjones1]

Dusty,

First make sure that there is no swarf in your work area that can be pulled into the motor. Mark both end covers with a scratch across the joint with the motor body so thay go back in their original position. Assuming there is some space between the pulley and the end plate give the end of the pulley end of the shaft a tap with a soft hammer. This should separate the brush end cover from the motor body. Do not remove the armature from the motor body unless you have a good reason to to so. The end cover should pull off easily once the joint with the motor body has been broken.

Les.

[DustyParticipant @dusty]

Les, the tap did do the trick, but, there is always a but, the bearing in the end cover is holding the end of the armature shaft. Fortunately there is enough room to get a puller on. I will dig it out in the morning and use that. I will set up a workmate in the garden well away from swarf while I clean and put it back together. The body and both ends were marked for relative positions, so one job I will not have to do.

[DustyParticipant @dusty]

Well motor has been taken apart and cleaned, I was a bit surprised in that it was quite clean inside a little bit of dust but nothing of any consequence. Is there any other tests that I can do on it before putting it back. This will not be until tomorrow now as I am off visiting and will not be home till late.

[John RuddParticipant @johnrudd16576]

Dusty, without further test equipment there's nothing more you can do unless you have a friendly motor rewinders near you who could test the motor for you….But it has to be on a dc supply…..

and they could megger it too, to ensure there's minimal leakage to earth….

Other than that, trust to fate…fingers crossed it all works….

[DustyParticipant @dusty]

I have found a local repairer who will test the motor, Lunch then in the car, hopefully I will have at least this question answered.

[Richard MarksParticipant @richardmarks80868]

While your at the repair shop ask the chap whether he has any better quality brushes that fit as the original ones are a bit suspect.

[DustyParticipant @dusty]

Oh woe is me. My motor is deceased it is dead it is no more. It appears that it is burnt out, this was either caused by overload or by a fault in the control board allowing to high a current to the motor. I am trying to contact Warco to find out the cost of a new motor, A rewind is approx.£300-00. Then I may need a new speed control board as well. I could be better off with a 3ph and VFD set up.

[Mark P.Participant @markp]

Dusty I got a new motor for my wm16 mill last year cost 90 quid, so the wm250 one shouldn’t be a lot more.
Mark P.

[Neil WyattModerator @neilwyatt]

If a rewind costs about the same as a VFD setup, it's a no-brainer!

[Mark P.Participant @markp]

Hello Dusty did you get a price of a new motor from Warco?
Mark P.

[DustyParticipant @dusty]

ah serious problems. Warco are unable to supply a replacement motor. The motors that they do have are somewhat longer than mine and consequently do not fit without a fair amount of work on the machine. I suspect that any new motor will require the same amount of work. The motor they do have would be £135-00 plus carriage of £15-00 plus VAT £180-00 in total. So if you have a WM250 lathe of about 7/8yrs of age beware, you cannot get a spare motor.

[Mark P.Participant @markp]

Hello Dusty, I have the same problem as you, gone for broke and ordered the new type of motor so will have to cut a big hole to fit it and make an end cover for it (sigh) It also involves a new motor pully as the shaft on the new motor is 14mm instead of 12mm.
Regards Mark P.

[JourneymanParticipant @journeyman]

That's a bit worrying, I have the same lathe (2007 vintage) still ticking over at the moment but in anticipation I found this motor inverter drive for much the same price as just a replacement motor. I have no idea if they are any good or not perhaps someone here has knowledge of this make.

John

Edited By Journeyman on 06/02/2017 17:16:29

[John RuddParticipant @johnrudd16576]

LS Systems used to be LG Industrial, LG used to be called Goldstar and produced brown goods ( televisions and vcrs amongst other stuff…) in Korea.

The motor is a Marelli brand is Italian, origins in Milan…

Cant vouch for any of these…..I've only used Teco or Invertek inverters and TEC motors….

For those trying to find a new dc motor, try SPG tools at Hinckley or Toolco in Stroud. Both companies market a similar size machine to the WM250.

[DustyParticipant @dusty]

Have any of you got the WM250 which for the primary drive has a toothed belt? Further does anyone know what speed the motor spins at on top speed. Either my maths are hopeless or the motor is very strange. The primary drive via the toothed belt is from 13 tooth to a 39 tooth simples 3 to 1 then from a 2.8dia to 3.75dia V belt gives a ratio of around 1.3 to 1 therefore if the lathe is running at 2000rpm the motor is running at 4500 give or take. or have I got it all wrong? Whoops need to reverse the size of the pulleys..

Edited By Dusty on 07/02/2017 15:31:50

[Neil WyattModerator @neilwyatt]

Posted by John Rudd on 06/02/2017 17:34:28:

LS Systems used to be LG Industrial, LG used to be called Goldstar and produced brown goods ( televisions and vcrs amongst other stuff…) in Korea.

LG stands for 'Lucky Goldstar' – sounds like a low-budget version of the Lone Ranger

Neil

[JourneymanParticipant @journeyman]

Dusty, I checked mine measured the pulleys and hitting the calculator worked out that when going flat out the motor is doing about 4500rpm. I don't think this is unusual for this sort of small brushed DC motor. If it was replaced with a more normal speed AC motor the pulley sizes might need changing to get a sensible speed range..

John

[DustyParticipant @dusty]

Thanks John I am relieved that my ability to make fairly simple calculations has not been lost. I have been looking at 3ph VFD set ups and as you say it would require fairly extensive re-modelling of the drive train to get a comparable speed range,

.

[JourneymanParticipant @journeyman]

Dusty, could probably be done by just playing with the motor pulley and a new belt. If the primary ratio was 1:1 then the low speed range would be 46 – 924rpm and the high range would be 182 to 3640rpm. Top speed might be a little high but the low range should be quite usefull. Those speeds are based an the data from the link I gave earlier where they say the vfd controls the motor from 140 – 2800 rpm.

John

[Mark P.Participant @markp]

Hi Dusty, I will be fitting the new type motor tomorrow, I ordered it yesterday afternoon so I will let you know how easily it is to fit. It looks like I will have to cut a hole in the back of the control box assy and a bit out of the splash back then make a box affair to cover the back of the new motor. BTW I found a chaffed wire in the back as well it is the mains live feed to the power board!
Mark P.

[John RuddParticipant @johnrudd16576]

When I changed the motor out on my SPG lathe ( WM 290 equivalent ) I went for a 2 pole motor, giving 2800 rpm at 50 hz….To achieve the desired speeds using the existing pulleys, I upped the speed on the inverter…..

With the frequency set, I can reach the top end speed of 2000 rpm at the spindle….on the tacho.

[Neil WyattModerator @neilwyatt]

What John R says. You can overspeed the motor with a VFD at the expense of some torque, which is not a big issue at high speeds.

Most TEC motors can run at 70 Hz continuously, so a 2800 rpm (nominal) motor will do 3920rpm all day, and happily go up to 4500 for short periods.

It is important to set the base frequency to either 50Hz or 60Hz even if you intend to run it faster as this sets the point where the inverter switches from constant torque to constant power.

Neil

[John RuddParticipant @johnrudd16576]

Ooops!…. My last post should have read….' I upped the frequency' on the inverter ' to get the motor to run faster

I'm sure you know what I meant….

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