Brook Crompton Parkinson motor

[Simpo Two]

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.

[Simpo Two]

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?

[Simpo Two]

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]

Regbuser said:

What is printed after ins class ?

Good question - 'something' MAX...

[Simpo Two]

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 fk-off Robert Sorby bowl gouge for the inside, sharpened the nuts off it and it still barely coped... but it was worth it:

[Simpo Two]

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!

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?

[Simpo Two]

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'...

[Simpo Two]

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.

[Simpo Two]

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

I couldn't find one that looked the same online, nor a model number on the casing, but it runs happily on 13A.