Brook Crompton Parkinson motor
Discussion
I have one of these beasts under my lathe, and whilst it works fine, I've noticed that after a while it gets warm, then hot, which strikes me as possibly not quite right. I presume it needs some oil - if I'm right can anyone explain how to do it please?
Note - the colour is a respray, it may have been different originally.
Note - the colour is a respray, it may have been different originally.
Look at the foil rating plate; the motor is probably continuously rated for up to 90°c.
But if you're still concerned:
Is the plastic fan (under the black cowl) spinning, as these rely on fan cooling (tefv)?
Are the end bearings both at the same (hot) temperature?
And no, oil in the space between rotor and stator won't help matters, should be air only.
But if you're still concerned:
Is the plastic fan (under the black cowl) spinning, as these rely on fan cooling (tefv)?
Are the end bearings both at the same (hot) temperature?
And no, oil in the space between rotor and stator won't help matters, should be air only.
Thanks. The foil plate seems to say 'RTG 30' but I'm not sure if that means it can only go up to 30C.
I didn't know it had a fan - the noise of the lathe obviously drowns it.
The warmth is on the metal case - the whole thing seems to get warm.
I was hoping there'd be a PDF etc online somewhere but I can't see a model number. Does anybody recognise it?
I didn't know it had a fan - the noise of the lathe obviously drowns it.
The warmth is on the metal case - the whole thing seems to get warm.
I was hoping there'd be a PDF etc online somewhere but I can't see a model number. Does anybody recognise it?
Need a better pic of the plate, particularly the line below the "RTG 30", which appears to be a time rating, i.e. you should only expect it to deliver the rated 370W for 30 minutes in every hour. If it were mine the test is can you put your hand on it when it's been running and worked hard, that is to say it's not hot enough to burn you; if it isn't hot enough it's fine and carry on.
hidetheelephants said:
Need a better pic of the plate, particularly the line below the "RTG 30", which appears to be a time rating, i.e. you should only expect it to deliver the rated 370W for 30 minutes in every hour. If it were mine the test is can you put your hand on it when it's been running and worked hard, that is to say it's not hot enough to burn you; if it isn't hot enough it's fine and carry on.
It was higher res when I uploaded it. Try this and see if it biggifies:
It hasn't burned me but I didn't think it should be hot to the touch. Never dawned on me you had to switch it off every half an hour!
Simpo Two said:
It hasn't burned me but I didn't think it should be hot to the touch. Never dawned on me you had to switch it off every half an hour!
Still can't read it; you don't have to switch it off, the rating means you can only use its maximum power output 50% of the time, in your case a maximum depth roughing cut in a tough material at or near the maximum swing; a piece of unhardened EN24 for example. In reality it's not possible to approach that rating as you will destroy tool edges, cover yourself in hot chips and swarf or just make the belt slip.hidetheelephants said:
Still can't read it; you don't have to switch it off, the rating means you can only use its maximum power output 50% of the time, in your case a maximum depth roughing cut in a tough material at or near the maximum swing; a piece of unhardened EN24 for example. In reality it's not possible to approach that rating as you will destroy tool edges, cover yourself in hot chips and swarf or just make the belt slip.
Well, this is a wood lathe so I have no idea what EN24 is, but the hardest wood I've ever turned is red mallee burl - which seemed pretty close to iron! I bought a f
k-off Robert Sorby bowl gouge for the inside, sharpened the nuts off it and it still barely coped... but it was worth it:
Regbuser said:
Ok, it's insulation class F, at ambient maximum.
Class F is good for 105°c, at up to 40°c ambient.
No idea how you read that, well done!Class F is good for 105°c, at up to 40°c ambient.
So it can actually boil water and be OK... remarkable. No need to oil it then
NB Presumably the lower the insulation the longer/hotter it can run as the heat can get out better?
Probably wouldn't hurt to check it isn't full of sawdust, could be all sorts built up inside which wouldn't help the cooling either. At least I usually assume that anything that ends up collecting on the outside of the case is probably even worse inside.
Are there black smudges on the case too near the end cover? Probably nothing important but could be worth checking where those came from (bearing grease/brushes/cooked sawdust)
Are there black smudges on the case too near the end cover? Probably nothing important but could be worth checking where those came from (bearing grease/brushes/cooked sawdust)
It's a totally enclosed fan ventilated (tefv) motor, so IP rated to at least IP54. Very little probability of dust ingress.
Put a thermometer on each end, and also listen to the bearing cups with a screwdriver.
Finally, is the supply cable getting hot? Is there a capacitor on the side that's getting hot?
Put a thermometer on each end, and also listen to the bearing cups with a screwdriver.
Finally, is the supply cable getting hot? Is there a capacitor on the side that's getting hot?
pquinn said:
Are there black smudges on the case too near the end cover? Probably nothing important but could be worth checking where those came from (bearing grease/brushes/cooked sawdust)
Could be a mixture of grease and cooked sawdust. Regrettably I don't have the equipment or knowledge to investigate much further as per Regbuser's suggestions. Bearing cups? No sign of a capacitor, just what you see. Just thought it might need some oil in a little hole marked 'oil'...Capacitor would be in the box the wire goes to.
Bearing cups are the outside bits of the bearing that sit into the case and dont move, if you managed to rest a screwdriver against them and had the motor turn you'd hear if the bearings were rumbling.
For a quick look all you should need is a screwdriver to take the lid off the connection box, and to take the fan cowl off so you can see if anything is going on underneath.
Bearing cups are the outside bits of the bearing that sit into the case and dont move, if you managed to rest a screwdriver against them and had the motor turn you'd hear if the bearings were rumbling.
For a quick look all you should need is a screwdriver to take the lid off the connection box, and to take the fan cowl off so you can see if anything is going on underneath.
Thanks for the clarification. I'd have to get the motor out to do most of that, so, if it's designed to run warm, I'll leave it. Used it for 15-20 mins this morning and it was 'warm' - but I have no way to measure it exactly. Also, as turning is only a hobby, it's no problem to take a break after a little while and let it (and me!) cool down.
It's fixable... said:
If its a "special" imperial motor then when it finally packs up pop it down to Colchester Rewinds & Repairs (which I think are local to you) for a rebuild.
If its a standard metric motor you'll be able to buy a brand new one cheaper than rebuilding.
Very useful, thanks If its a standard metric motor you'll be able to buy a brand new one cheaper than rebuilding.
I couldn't find one that looked the same online, nor a model number on the casing, but it runs happily on 13A.
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