Plenty of standard induction motors down to about 1/4 HP (180w) about (new), below that you possibly looking at shaded pole motors and I'm not at all sure what the torque curve for those looks like, and whether they'd be suitable for a lathe. You probably need to talk to a motor supplier to see what they can offer. A 1/4 HP would be fine on a small lathe, if you're worried about getting a jam up just let the belt run loose enough to slip or include a coupling somewhere with a weak shear pin.

For a motor, contact members of your local Model engineering group/society, usually some one has motor for sale or knows of some one who has. Modern washing machine motor run far to fast and are very noisy and have no protection against bit entering the windings. Shaded pole are no good either. Get your self from some where or other a split phase or capacitor start 1425 rpm motor. Lathe motors start off load so starting torque doesn't really matter. Motor do get warm and modern ones get HOT to touch,its when you get that burnt varnish smell you start to worry, even all's not lost. When capacitor start and run motors are up to speed and the centrifugal switch opens they then behaves or run in a similar manner to a the straight capacitor start motor.Ted

The whole idea of the switched capacitor start motors John is to provide sufficient torque to get all of the parts on a lathe spinning and up to speed. Then that capacitor is switched out. It's not unusual in a number of areas to find that the torque needed to do that in a reasonable time or even at all is more than the actual running torque.

One of my favourite places to look is ebay new other. All sorts crop up. There appears to be some pure capacitor run motors on there at the moment but going on the one I used they don't arf get hot what ever load is on it.

John

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Pure capacitor run motors, those with a permanently connected capacitor and winding not the common capacitor start ones with centrifugal switch, are compact relative to power output and can frequently be found quite inexpensively. These should be avoided as they are not suitable for varying loads and get very hot if left to free run or used when lightly loaded. Which generally occurs a lot on machine tool duties.

This sort of motor is intended for fan and similar applications low torque demand at start up is coupled to high demand at rated power with a rapid rise as speed increases towards and above rated speed. They are a pseudo two phase design where the interaction between the main winding, capacitor winding and capacitor comes into balance to produce a very efficient machine a rated speed and load. Unfortunately the sweet spot is quite narrow and outside it the motor becomes very inefficient with large, unproductive, currents circulating making it very hot indeed. Running off load they typically become far too hot to touch after a minute or so and meltdown in five to ten. However when correctly matched to the right type of load and running for long periods of time they last for ages. Not only are they very efficient but also a the cheapest and most durable, typically close to 3 phase in lifetime, type of single phase motor outside the mouse power region so they are often found in scrap machinery.

Pity we can rarely use them. I wrecked tow nice ones before finding a book expelling the design!

Clive

I have one 150W 1450 rpm shaded pole capacitor run motor driving the line shaft in a model of a workshop, I had the workshop at a show a couple of years ago, and left the motor running, after 1/2 an hour or so a lot of the magic white smoke found it's way out of the capacitor, and things came to a stop. A new capacitor, and it's up and going again, but not a continuous run motor, maybe 10/15 min.

Ian S C

Nick, those motors run well less than their maximum power rating, and have a great cooling system, the load is the system, the main thing to go wrong with them is muck in the bearings, then the bearings running dry, they are usually Oilite bushes.

Ian S C

On the small lathe i have , similar size to your myford M l 1 ish as im guessing this is the machine you going to hang it on… I used the motor off one of those small hobby drilling machines. See machine mart ,item-Clarke cdp 5rb [ they were much cheaper a few years back , B&Q at one time were selling them £ 29.99 , which was tenner cheaper than the one i"d bought a few months before, so i bought a second , i figured that was an acceptable price for a motor ,couple pulleys ,pair of bearing ,and a drive belt an a few other odd bits ] These are capacitor run motors ,and yes as other folk have already said they Do run a bit HOT ! And i did wonder if that was going to be an issue ! So i thought i would really give it some , as in if its going fail ,best fail now. So i ran it dusk till dawn = a good 10 hours ,didnt even turn it off when i stopped for tea break [ it was a fair sized job , 6 inch dia by 9 inch long—the job was wood former for a small furnace barrel — also it was driving through the back gear ,and running power feed….it didnt fail!! it seems that when this type of motor fails its usually the the capacitor that fails …[ possibly cos one side of the cap is in contact with or very close to the hot motor casing, easily fixed ! Anyway point is machine mart have a spares department maybe the motor is available as a spare, might be worth giving them a try ,or maybe similar is available on ebay ? These motors seem to come 2 sizes 250 & 350 watt not much in it size wise the 250s a bit smaller, it was 250 i used, also the motor starts with the load off ,the way i rigged the drive, thought id at least give it a bit of a chance . bodge.

ps I know thats a long time to turn a wood former , But i really was trying to get motor to fail !