Shopfox jointer - turning off after a few seconds

[Bill_L]

Hi,
We were using the jointer yesterday (milling ~12" x 4" pieces of walnut) when it turned off. That has happened before and you take the back off and push the reset switch and all is good. Now, the jointer runs for a few seconds and then turns off. I think it could be the belt. In one of the videos I took (will try to upload) the belt appears to be loose. With a little help - we got it tighter but it still turns off after a few seconds. Should I be setting the motor in place and then trying to attach the belt? I thought the weight of the motor would be sufficient to keep the belt tight but perhaps not. I have ZERO electrical intellect, maybe less - so any electrical questions will be lost on me. It is on a separate 240V plug and that is not getting tripped. Any thoughts? Thanks.

 

[mark2]

Not being an Electrician, I am sure there is better advice available, but I would first check that all wires in the plug are securely connected. If that didn't show any trouble or cure the problem, I would look for mechanical resistance in the cutter head or motor by spinning each with power disconnected and belt removed.

 

[Mike Davis]

If it is tripping the motor reset then something electrical is not right. The belt would have absolutely no effect on that.
Could be loose connection, sawdust in motor, bad capacitor, etc...

 

[Craptastic]

Centrifugal switch or a capacitor is my guess.

 

[Bill_L]

Okay. I'll review the wiring and see if anything looks loose. Thanks.

 

[bob vaughan]

It could also be corroded contacts in the switch. Anyway you can wire the motor direct to the outlet bypassing the switch?

Below, the bottom blackened set of Asian made contacts are chewed up from arcing corrosion. This switch had a label that read 12-14 amps, 3 HP at 240 volts.
At the very bottom is a contact from a NEMA grade switch with the same specifications.

 

[Bill_L]

I looked at all the connections and one seemed bad (1/L1 - top left corner if you look at the wiring.png file). It was the red wire and the u prong was burnt and I couldn't see any wire. All the other connections looked okay. I replaced the burnt u prong but the jointer still stops running after a couple of seconds. When it shuts off - there is a flash of light that's visible in the 1L1 / 2T1 and 5L3 / 6T3 areas. The troubleshooting guide notes the start capacitor could be at fault and to test/replace. Another option could be the centrifugal switch at fault and to adjust / replace switch if available.

The wiring guide and actual wiring aren't lining up. On the guide - it has a yellow wires going from 95NC to 14NO. I have no yellow wires. Instead, there's a red wire that I don't know where it originates from going to 14NO. And I don't have a yellow wire from that goes from 96NC to A2. No wire was going into A2. There is a red wire that goes from 95NC to 5L3 in my picture. So if I'm to follow the wiring guide - I have no idea what to do I've had the jointer for ~8 months so I would assume it was wired correctly but maybe not?

I've ordered a capacitor and centrifugal switch from Grizzly. I wasn't able to find the same sized capacitor on Amazon and the parts were relatively inexpensive at Grizzly. We'll see...Serves me right - I said I wanted to make more shavings and less saw dust. My hand is being forced!

 

[Mike Davis]

That box holds the contacts like Bob was showing. If there are sparks there the contacts could be burnt just like Bob was saying.

I would take that box apart to inspect the contacts. Or if you are not experienced enough then get someone to check it.

 

[Bill_L]

I saw the contacts on the side of the box and those looked good. I’ll try to take apart the box to see if the contacts are burnt.

 

[Rwe2156]

I would have bought a new switch. We’ll see….

 

[Bill_L]

With a little (okay - A LOT) of help from Mike Matthews we have this figured out. There are likely a couple of issues. The centrifugal switch was pitted and had a bit of burning. We cleaned that up eventually got the motor running. But it wasn't running well. We swapped out the switch capacitor from the bandsaw and tried it in the jointer and it worked. Interestingly enough - there is a switch capacitor AND a running capacitor on this jointer. I ordered the wrong one yesterday so I ordered the right one today. I'll replace both as well as the centrifugal switch. Pretty sure that will do the trick...

 

[Craptastic]

Sounds to me like the centrifugal switch started misbehaving and it went on just long enough to pull the running cap off balance trying to fire the windings with the start cap still firing (and continue to after start was complete) and make it bad too.

Glad you got it sorted.

 

[Michael Mathews]

With a little (okay - A LOT) of help from Mike Matthews we have this figured out. There are likely a couple of issues. The centrifugal switch was pitted and had a bit of burning. We cleaned that up eventually got the motor running. But it wasn't running well. We swapped out the switch capacitor from the bandsaw and tried it in the jointer and it worked. Interestingly enough - there is a switch capacitor AND a running capacitor on this jointer. I ordered the wrong one yesterday so I ordered the right one today. I'll replace both as well as the centrifugal switch. Pretty sure that will do the trick...

Minor correction here with nomenclature. What Bill means is the Starting Capacitor. The Running Cap is fine but the Starting Cap clearly has some bulging on the terminal end. This was a clear giveaway that it may be failing or has failed. After installing the Bandsaw Starting Cap, there was a good bit of arcing around the centrifugal switch. Turned out that we hadn't reinstalled it quite far enough onto the shaft to make good contact with the OFF position contact. After moving it in about another 1/32" or so, then the motor fired right up nice and smooth. He already had a new centrifugal switch on the way and just needed to order a new Starting Cap.

 

[Bill_L]

Thanks for the clarification Mike!

 

[chris_goris]

Is the magnetic switch staying engaged (powering the motor)?

 

[Bill_L]

The centrifugal switch was fine - it was the centrifugal plate that was bad (pitted). I didn't pay close enough attention to know what needed to be replaced. I learned a lot through this process - helped that Mike was there to explain quite a bit of it. So I have a new starting capacitor and centrifugal plate. Grizzly charges a restocking / return fee so not worth shipping the running capacitor or the centrifugal switch back. I'm happy to have my jointer back in working order.

 

[tvrgeek]

Glad it is fixed. Just one more tid-bit. The on-motor switches are bi-metallic usually and will fatigue if tripped several times.. Sometimes they are replaceable, sometimes not.