Motor for Myford Speed 10

I have purchased a Myford Speed 10, it look like it hasn't been used much condition. The motor attached is 0.25 HP. It is operated only a plugging it in. No switches. Not want to use the lathe like that I checked that it worked and have fitted a cheap NVR switch. This works fine.

On operating the lathe at it highest gear - 2000 rpm the motor failed to to get up to speed and started to smoke.

I have an old Hoover motor also of 0.25 HP. I which I have never used but it seems to work. I fitted that and found that it tripped out before getting up to speed. I am thinking that 0.25 HP is too small to pull such a high gear. Does anyone know what size motor should be fitted?

(There doesn't seem any untoward resistance in the counter shaft or head of the lathe. I haven't cut any metal with it yet and the screw banjo is not engaged). Thanks, Roger

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ML7 usually came with 0.5hp. But its top speed was only 800rpm. So I should think .25hp is way too low.

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Hoover made millions of Sewing Machine motors of the Universal Type which aren't ideal for lathes. The motors run at high RPM off-load, and slow down when asked to do work. Universals are OK for vacuum cleaners and tiny lathes but bigger machine tools prefer motors with high starting torque and fixed speed running: for an ML10 a single or three-phase induction motor delivers a better combination of torque, rpm and power. A ¼HP Universal might stall before it can get up to speed, whereas the extra torque available from a ¼HP induction gets it going.

What you have may be suitable because Hoover made induction motors too. The giveaway is Universal Motors have brushes.

In terms of power, between ⅓HP and 1HP is typical on home workshop machines. ¼HP is on the low side for an ML10 I think. If I owned one I'd go for ½HP or ⅔HP. Ought to say I'm constitutionally against of putting big motors on small machines because doing so risks rapid wear and serious damage if anything goes wrong like crashing the tool-post into the chuck. Others think I'm a wimp!

Myfords were originally fitted with single-phase induction motors because homes rarely had the 3-phase supply needed to power better 3-phase motors. These days 3-phase can be generated electronically with a VFD so I'd almost certainly go that route. Advantages: speed control, improved reliability, more torque (at operating speed), and much less vibration. If nervous of rolling your own you can buy complete packages, for example Newton Tesla.

Dave

My ML7 ran for donkeys years with a 1/4hp Hoover single phase motor, but as others have said it only did ~600 rpm

Hoovers made lots of induction motors, many more than their universal motors. Might pay to ascertain which type of Hoover motor you have.

Andrew.

I have a Speed 10 and although the manual recommends a 0.75hp motor mine has 1/2hp and is slightly underpowered as a result. This however only shows when using the motor drive belt in the top speed range position and yes I too have suffered the old clicking and smoking motor situation. Worst on cold mornings. What I do if I need to use top speeds is to disengage the belt tension lever (between the countershaft and spindle), switch the motor on, let it get to full speed then slowly re-engage the belt. In my case that gets it going full speed. I then leave it running a while until ready to use it. I think the standard ML10 is recommended a .5hp motor but the Speed 10 definitely needs the .75hp.

john

Thanks for all your responses, I shall look out for a 0.75 motor.

Can swap for 2 x 0.25 hp motors!