Electric Motor Experts, Get in Here - CNC Issue

[andy_con]

Wondering if someone may be able to shed some light on the subject??

so i have a new fancy cnc machine but ive been having a few issues with it. The spindle stopped spinning intermittently. then the machine was switched on but not running and it tripped the RCD.

Now everytime i turn the machine on the RCD trips straight away.

With the help of Dan we traced back the fault to the motor or cabling to the motor.

probably a bad idea but yesterday i removed the RCD and turned the machine on, the spindle started spinning slowly and there was a lot of smoke from the motor. the spindle shouldnt of moved and nothing was telling it to move. machine was on for about 3-5 second and i turned it off straight away, interestling no fuses went.

so started taking things to bit and found the source of the smoke -



my old man pop round who knows way more than me and he recons that there was a lot of carbon in there, probably causing but years of use. i started cleaning the area up and noticed one of the wires going to the brushing where the black burn area is was stuck to the floor. so scraped and cleaned away to remove the wire.

i then turned the machine on and bingo the RCD didnt trip, so i activated the spindle on a slow speed and bingo it spun. i stopped the spindle and after about 5 second the RCD tripped again and there was a little bit of smoke.

so the question, could years of carbon building up be causing this issue? could i take a bold step and remove the RCD and let the carbon burn away or is that just a stupid idea?

does anyone have any diea how you go about getting into a motor like this to clean it up?

[dave]

Take the motor to a motor re winder - someone who knows what they are doing

[andy_con]

getting the motor out = big ball ache

do such places exist?

[dave]

http://www.yell.com/s/electric+motors-essex.html

[andy_con]

lol thanks dave

[tonyaztec]

Whoops,
http://www.3eservicesinc.com/Manufacturer/SEM/MT30U436

[tonyaztec]

I would question if the output card may have failed, as you say it should not have moved as you just turned it on, it may be the output card has sent out AC instead of DC, I would check this before putting a new motor in.

[Things]

Sounds like the motor has shorted to ground and other windings, not really user serviceable at all.

[chad]

EDIT* oh yeah, DO NOT TRY TO RUN IT ANY MORE!

First thing, look and see if you can find a new-old stock motor some ware cheap and just replace the thing. Have the old one rebuilt down the road then you have a spare ready to go .

Second, like others have said take it to a motor repair place. They have seen motors like this and will know what to do to get you back up and running.

Third. Pray you haven't baked the motor driver. They don't like to be shorted. That could be a real pain if something is broken.

So start with the motor. That is not a normal condition and you are not going to be able to half ass fix it. It needs to be replaced or rebuilt.

chad

[dave]

It appears the motor is made in London, so SEM would be a good place to start I reckon