Drill Press repair question.

[alchemysa]

Hello all. I picked up old Ryobi drill press for free. It works fine except that the motor needs a quick spin by hand to get it going. Once its up to speed its got plenty of power. I know the problem is not belt tension because the problem occurs without the belt even attached. I took the brushless motor apart and it looks pretty good inside. So I'm guessing the problem is the 'starter' (I think thats what its called) attached to motor. Do you think I'm on the right track, and are these starters easily found at, say, electric motor repairers? The pic attached is not my drill press (its just a pic I grabbed off the net) but its basically the same with the 'starter' arrowed. Thanks for any help.

 

[irvingj]

Sounds like a CSIR motor-- "Capacitor Start, Induction Run."

Does it have a metal oval-shaped "can" attached to the side of the motor -- the thing you thought was a starter? (Looks like it in your pic.) If so, that's probably what it is. The capacitor's function is to phase shift the AC power on the start winding(s) to give the motor a bit of a directional "push" to get it going.

And yes, they can easily be replaced, and may well be the problem. And yes, an electrical shop --or refrigeration supply house-- should be able to match it up.

If that doesn't do it, the start windings may be damaged, in which case it would probably be best (cheapest) to just replace the whole motor.

 

[dex3361]

I agree it sounds like the start capacitor or the start switch/centrifugal switch. The start capacitor is typically only in the circuit at the moment of starting until it comes up to speed then it is dropped out of the circuit either with a centrifugal switch or a voltage sensing relay or even a timing relay. Let us know you make out here. Free is a good price.

 

[alchemysa]

Thanks. It sounds like I was on the right track. It runs strongly once it gets a shove in the right direction so I'll try and get a replacement capacitor. When I said i 'picked it up' for free I really meant it. Someone was throwing it out on 'hard rubbish day'. I saw it when i was walking the dog. They also threw out a 1 ton chain hoist - something else that I'd been wanting - A bit of RP7 and it works like a charm again. Its amazing what some people throw out.

 

[dex3361]

When you get it started does it click as it approaches full running speed? The click would be a centrifugal switch.

 

[alchemysa]

When you get it started does it click as it approaches full running speed? The click would be a centrifugal switch.

No, no clicks. And nothing I can see that resembles a centrifugal switch or sensor. It just appears to comprise of a capacitor and brushless motor. And I didn't notice anything inside the motor when I pulled the rotor earlier but perhaps I missed something. The capacitor says C8860 6uF +/-5%, 400v AC. Won't be hard to get I think. Interestingly it appears to run fine in both directions depending which way I spin it. Also interesting is that this old Ryobi press is identical, except for color, to a new (but cheap) press I bought about year ago. This old press will be great to have in the shed at the beachhouse.

 

[irvingj]

alchemysa- yep, that's what the capacitor's for-- to "push" it in the correct direction. I'm sure your starting set-up is the "back EMF" type, with no centrifugal switch.... but it's been so long I'm not sure if I'm remembering correctly. The important numbers on the cap are "six microfarads" and "400V."

I've been out of the refrigeration business for 20 years, but do remember we always carried an assortment of start caps (and start relays) in a neat box, so we could cover just about anything we came across. We'd test with a known good cap, and if that worked, we'd leave it there and return later with a proper replacement.

Sounds like you got a good deal-- a decent drill press is a handy thing to have around!

 

[alchemysa]

Just to give some 'closure' to this. Yes it was the capacitor. Put a new one in (about $12 Aust) and it works perfectly. Thanks for your help gentlemen.

 

[irvingj]

Thanks! Closure is good; a $12 drill press is even better!!