I have just purchased a Boxford Lathe

[Pete.]

In that case you have a fault somewhere. Avoid running it again until you've found out where the fault is. I'd be suspecting the centrifugal switch in the motor.

 

[123hotchef]

could it not be the capacitor?

 

[Pete.]

It might be but it's unlikely. Disconnect it and see if the motor hums. Pulling the belt should set the motor spinning and if it runs up but doesn't throw the trip then it's the cap that's at fault. Try not to lose a hand when doing this.

 

[123hotchef]

that is on the to do list for tomorrow then thanks again for the pointers

so just drop the motor down and remove the belt to test that theory too

 

[Pete.]

No, you need the belt to spin the motor. The capacitor's job is to bias the start winding to force the motor to run in the direction you want. Once it's up to speed an internal switch cuts the start winding (and the capacitor) out of the circuit or it gets hot and draws a lot of current. If you remove the capacitor the start winding is removed from the circuit so the motor doesn't know which way it's supposed to start turning, it usually just hums loudly (as well as getting hot and drawing a lot of current). Yanking the belt sets it off running.

Just had a thought - slip the belt and make sure the spindle turns freely and isn't tight. You've been messing with the back gear I wonder if your problem isn't simply very high starting loads because of something you've done up top.

 

[123hotchef]

No, you need the belt to spin the motor. The capacitor's job is to bias the start winding to force the motor to run in the direction you want. Once it's up to speed an internal switch cuts the start winding (and the capacitor) out of the circuit or it gets hot and draws a lot of current. If you remove the capacitor the start winding is removed from the circuit so the motor doesn't know which way it's supposed to start turning, it usually just hums loudly (as well as getting hot and drawing a lot of current). Yanking the belt sets it off running.

Just had a thought - slip the belt and make sure the spindle turns freely and isn't tight. You've been messing with the back gear I wonder if your problem isn't simply very high starting loads because of something you've done up top.

ill have a look at that tomorrow too, it may be but to be fair i have not had it running since it left the sellers house 3 months ago,

 

[123hotchef]

Ok motor ran for 30 seconds today. Then i removed the belts and it made a horrible noise with the belts and capacitor disconnected. Reconnected the cap and it ran for about 45 seconds

 

[123hotchef]

It's a old one.

 

[123hotchef]

next job is to remove the motor then I guess, or is it worth replacing the cap?

 

[Hopefuldave]

next job is to remove the motor then I guess, or is it worth replacing the cap?

The cap will only be a few Local Currency Units, but if you're replacing the motor it's probably A Good Idea to go with a 3-phase motor a bit bigger with a VFD, 3-phase motors are inherently smoother so you get less vibration, better surface finish and less chatter - the VFD let's you tune spindle speed finely and gives the option of rapid braking, rapid reverse, all sorts of goodies!

Dave H. (the other one)

 

[Pete.]

next job is to remove the motor then I guess, or is it worth replacing the cap?

Pull the motor and the cap and bring them round to mine and I'll check them over for you. I suspect the centrifugal switch is stuck.

Whilst you're here I'll show you a couple of vfd-powered machines running then you'll be hooked on the idea.

 

[123hotchef]

Thanks guys ill get that motor out over the weekend. Weird how it just didnt want to work properly after putting it in the workshop.

 

[God mode restorations]

What you need is this set up. Just got mine today.

 

[123hotchef]

What you need is this set up. Just got mine today. View attachment 179266

crikey! motor porn! ok what would that little lot set me back for my little Boxford Spencer?

Oh and what is it all!

 

[slimjim]

I broke the centrifugal start capacitor internal switch on my Chester 626 mill, when I replaced the bearings, I just removed it and replaced it with a push switch, I just have to push the switch to get the motor to run,

I intend to replace the motor with a 3 phase VFD controlled motor, the bodge was just a temporary measure, to get the mill working.

 

[slimjim]

What you need is this set up. Just got mine today. View attachment 179266

Looks expensive, what hp is the motor?

I would be looking at a similar setup for my Chester 626 mill.

 

[Brad93]

Looks expensive, what hp is the motor?

I would be looking at a similar setup for my Chester 626 mill.

2.2kw is about 3hp isn’t it?

 

[slimjim]

2.2kw is about 3hp isn’t it?

A bit to big for my Chester, which has a 1.5hp single phase motor.

 

[God mode restorations]

2.2kw is about 3hp isn’t it?

Yes.

 

[eLuSiVeMiTe]

crikey! motor porn! ok what would that little lot set me back for my little Boxford Spencer?

Oh and what is it all!

Can pick up a 2hp 3 phase motor for just over a ton. VFD from 60 upwards. Controls you can build yourself.