Wheel doesn't start on its own

[Heeke]

Hello,

I am new to the forum.  I bought a used Tormek SuperGrind2000 a couple years ago and use it once a month or so to sharpen lathe chisels, planer knives and anything else that needs sharpened.  It has really made turning and wood working much more fun.     

Recently it has started not starting on its own, I have to bump the wheel a little to get it going.  Interestingly it doesn't seem to matter which way I bump the wheel, it runs in either direction.  I thought maybe it was misadjusted or something so I took the rubber driven wheel off and can get the same behavior with the motor only.  At certain points when I turn it on the motor just hums, give it just a touch of spin and it seems to run fine. 

Is this a sign of trouble to come, or just the way it is?

The machine is Serial Number 312125 can anyone give me an idea how old the machine is?


Thanks,
Greg

[Jeff Farris]

That's a problem with the starting capacitor of your motor.

[Heeke]

I looked at the start capacitor and can believe that its the issue.  Apparently the previous owner used a little too long of screws to secure the horizontal tool holder.  Its not hitting hard, but there are witness marks where it hit. 

Is the capacitor available separately? 

Thanks
Greg
 

[Herman Trivilino]

The capacitor is the last item on the list shown here ...

http://sharptoolsusa.com/index.php?target=part&partsProdID=193&catID=6

The price is $29.61 but you might be able to find it cheaper locally. 

I'm curious about something you said.  If you you push it either direction it starts moving!?  Does it keep moving in that same direction?

[Ken S]

Welcome to the forum, Greg.

Considering a new motor would cost $311, I would say a new starting capacitor would be a good investment.  You may be able to install it yourself.  If not, it should be a quick and easy job for a motor repair shop. 

Being able to run in either direction reminds me of a "one lunger" (a boat with a single cylinder motor, which ran in reverse by starting the motor in the opposite direction..

Ken

[Heeke]

Thanks a lot for the replies.  I saw the cost of the motors, that was more than I paid for the whole machine with most of the jigs and fixtures and was considering "trying to make something work". 

Really appreciate the link to the parts site!  I am sure I can replace it myself, it doesn't look that hard and I will put shorter screws in so it doesn't happen again!! 

My Grandpa had a boat motor like that also, brings back some good memories.  If I remember right you didn't even have to stop it to start in reverse, just retard timing to near TDC, and with a little practice you could flip the timing change directions.  I found it pretty fascinating. 

Greg

[grepper]

Hey Greg,

I am curious about the question Herman asked... Does it  keep running in whichever direction you push start it?  Sort of sounds like it from your boat motor comment, and you said "It runs in either direction".

Anyway, if it does keep running in whatever direction you push start it, I'd like to get a failing capacitor for mine too!  That actually could be handy.  Grind with or into the wheel just by stopping/restarting. 

[Heeke]

Well I tried to upload pictures but don't think its working, if it does here is what it looks like when someone installs screws that are too long into the horizontal tool holder.  If not I guess you will see not so interesting text. 




grepper - yes it runs each continuously in whichever direction I start it.  I am mostly just cleaning up the edge of turning tools so I am not putting high loads on it.  I do not notice a performance difference in either direction, but it had a screw pressing on the capacitor which could be adding load to the drive wheel.  I would not recommend that solution

[Jeff Farris]

Hey Greg,

I am curious about the question Herman asked... Does it  keep running in whichever direction you push start it?  Sort of sounds like it from your boat motor comment, and you said "It runs in either direction".

Anyway, if it does keep running in whatever direction you push start it, I'd like to get a failing capacitor for mine too!  That actually could be handy.  Grind with or into the wheel just by stopping/restarting. 

Except, it has zero torque when it is turning the wrong way. The motor doesn't pull into the drive wheel when pressure is applied.

[Farmer Giles]

On the Supergrind 2000, to get to the start capacitor, take of the buffing wheel, its a 19mm spanner and its a standard direction thread. The capacitor is between the motor and the back plate of the grinder and is bolted using a 13mm spanner, the motor will swing away to give you access. The start capacitor is 4uF 400V B or 450V C. The body is 29.4mm diameter and 50.3mm long. There are 4 spade terminals at one end of which only 2 are used. There are only 2 connections to the component but 2 spade terminals per connection, I checked this with a meter. There is a black cap that covers the spade connectors.

Replacements seem to be around 3 GBP plus postage and they are ubiquitous, used in many appliances such as vacuum cleaners etc.

I'm putting my grinder back together while I order one as it takes 2 minutes to do this and I can keep using it with a little kick by hand  You can get capacitors with fly leads, I would get the same form factor with spade connectors, there are loads on fleabay. Physical size wise, I wouldn't get it any fatter but a bit longer seems fine, the replacement I have ordered is 25mm x 55mm. It also comes with a cap for the spade connectors.

Regards
Andy