Think I have burnt out my lathe motor

I think I have burnt out my motor things were getting hot then smoke started coming out of the casing before I could hit the stop button something went bang and the lathe stopped. Are they prone to killing motors. Were do I get a replacement.

You may need to post some specifics, like the lathe make and model, some photos etc. Or we could just guess?

I'll guess it was the footman in the pantry with a knife.....

Pete

Hi Dave,

I assume you have contacted the supplier? When running a variable speed motor slowly, cooling may be inadequate so the motor gets hot. Some add an extra fan that always run at full speed.

Thor

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There is a fighting chance that Dave's lathe is this one: **LINK**

http://www.model-engineer.co.uk/albums/member_photo.asp?a=30894&p=500175

MichaelG.

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Edit: Which suggests that it's from SPG

http://www.spgtools.com/viewtool.php?pid=37

Edited By Michael Gilligan on 14/08/2016 07:03:34

Thought I would bump this, before it falls off the bottom of the page.

It seems highly likely that Dave has a 'UCL' [Ubiquitous Chinese Lathe]

... There must be plenty of guidance available from fellow owners

MichaelG.

Not from those of us that have had many years trouble free running from our UCLs I also have a feeling that SPG are the only ones that do that specific lathe.

Are you sure the smoke came from the motor and not the board?

What were you doing at the time eg. Speed, depth of cut, material, how long running at that set up, etc

Edited By JasonB on 14/08/2016 13:14:41

Are they prone to killing motors.

'They' being lathes? No.

Mostly, electric motors are very reliable. Usually damaged by incorrect usage. But if it is Chinese, that generalisation may be being a bit stretched.

All motors will burn out if run under load too slow for too long. Fuses won't protect you under those circumstances (I learnt that the hard way).

If you have a VFD it will try and stop you doing this by reducing the motor drive current, but DC motors don't usually have this sort of protection.

If 'things were getting hot' enough for you to notice, then you probably overdid it.

If an AC motor you should find a replacement easily enough, but if DC best start by contacting your supplier - be warned powerful DC motors tend to be more costly.

Neil

If it's a single phase motor with a start winding, another possibility is the centrifugal switch contact may have welded closed leaving the start winding continuously energised. That winding is only designed to be energised briefly.. . . . . . . .How do I know?. . . . . .

Neil's correct. They can all burn out at reduced speed, Inverters help with either a thermistor in the motor or modelling heating effects. The same could be done with dc motors

However windings can short, brushes on dc motors wreck coms and all sorts of odds and ends might happen. Some especially capacitor run seem to run rather hot.

I overloaded my boxford normal ac motor once. I noticed the smell before anything else so switched off. It takes a while for the smoke to get out after it's turned off though. Replaced but it didn't do any lasting harm to the motor. I decided a bit more power was a good idea especially as I fitted and inverter so doubled it. Going from say 1/2 to 3/4 hp or 3/4 to 1 is more usual.

John

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Looks identical to my Amadeal AM210, you need to establish if it is the motor or the electronic board, if things go bang it is usually the electronics/fuses rather than the motor. When using slow speed a lot, you should wind it up to max for a few minutes every so often to get some cooling air through the motor.

My lathe is the one the link takes you to in a previous post. I purchased it from SPG.http://www.model-engineer.co.uk/albums/member_photo.asp?a=30894&p=500175

I was turning a piece of bar stock down to 6.5mm. The lathe was not running particularly fast. I was using a carbide.

The ba rstock was of unknown origin and it seemed to be taking a bit of cutting. Things were getting a bit warm I noticed smoke coming from the area were the motor is. before I could stop it there was a bang and everything stopped. I suppose it could of been the board or the motor. I'm taking the motor into work to morrow hope fully they can test it and tell me if its goosed. I am new to this so I may be a bit vague in my description. If it is the motor what are my options could I beef it up or is there a better way to power it. If its a board I guess its going to be pricey.

Ill know better to morrow I hope.

Edited By Dave Harding 1 on 14/08/2016 19:11:17

Hmm. Motors don't usually go bang, so you may be looking at a broken controller PCB. Low speed and high torque suggests high currents in the power components which is a relatively stressful condition.

It's fairly likely that any damage on the PCB would be visible (blackened and / or cracked components). If the motor appears to be OK, that would be the next thing to look for.

Murray

With carbide you need speed, most carbide lathes tools aren't very sharp so using tehm at low speed will put a big load on the motor.

Questions to answer are what speed, how deep a cut and how long had you been going at the bar for?

Neil

I was running at a fairly low speed I don't know exactly my read out stopped working. The material is not stainless not sure what it is really it seemed to be taking a age to machine. I was taking relatively small cuts. I was at it for quite awhile I had machined one end then turned it round to reduce the OD from probably 20mm down to 6.5 mm over a 4" length so it was running a while. In hindsight reading some of your replies I should have been running at a higher speed. It might well be the board that is fried. There are no burn marks on either of the boards so nothing obvious.

You may be able to test the board by replacing the connections to the motor with a 60 watt old type bulb.

Try googling for more info

When a motor overheats I find it best to not switch off, but remove the load and let the motor run at full speed, this will cool it down quicker than switching off.

It's not the motor I have had it checked out and it's OK. So it must be some thing else may be the board.

If you can find the identification details on the board, you should be able to geta replacement from the importer.

You could try running the board identification past Ketan at ErcEuroTrade. He is very helpful, and ARC carry spares for the Seig C2 and C3, (they use DC brushed motors, but with different, non interchangeable, speed control boards) so you may get lucky.

Howard