I just bought a Powermatic 63 second hand this weekend. It worked fine and was able to cut without issue until I changed the saw blade. Now it hums for a sec and blows the fuse when I turn it on. I've taken the blade off with the same result. If I remove the belt the motor runs fine. If I try to turn the axle the blade is connected to manually it barely turns.
I'm afraid I over tightened the nut and broke something. Please help!
You should be able to turn the arbor freehand... with no blade and no belt with little effort. IF NOT, the issue lies within. It's either frozen bearings or dried grease inside them OR a washer is where it shouldn't be OR is not where it should be. The pulley may have shifted on the belt end and is rubbing in something. Lower the arbor a bit and see what happens then? The drive pulley may be oversize and is rubbing on the underside somewhere?
My guess it's the bearings and replacing them is probably a good idea regardless.
If the saw was in storage for a long time and not used the grease in the bearings can dry up hard as a rock. Bearings are cheap but you may have to find a place with a press to change them out. My local Napa store does some machine shop work, they could do it. Just don't take a hammer to the saw arbor and try to drive the bearings off.
I placed a block of wood on the edge of the blade to keep it from spinning and then tightened the nut with a crescent wrench. Cant remember if I only made 1 1/4 turn or 2 after hand tightening but it didn't seem like I was overtightening at the time. However, I've seen other posts which say you don't have to tighten much because the saw will tend to tight itself.
I'm guessing the bearings seized when I tightened because after this the arbor turns VERY slowly even after removing the saw blade.
Going to try removing the arbor tonight to see if the bearings are seized.
it is used, how many years old? and sat for how many years? in what conditions?
a frequent "event" with old hardened / caked grease . . . bearings turn, when run they get hot, but the old grease does not go soft/liquid and spread to lubricate, bearings burn out/seize.
over tightening the spindle nut is unlikely - the design does not rely on the nut tightening the shaft in the housing/etc.
It was manufactured in 1995. May have sat unused indoors for a year or two. The saw looks to be in very good condition. No rust. Really surprising that the bearings would seize on a relatively young saw.
I removed the shell and legs from the top to better access the arbor last night. Need to get a bigger wrench to remove the arbor nut. It is recessed into the cast iron frame. Hoping the box end wrench will have enough angle to get it.
Well I got the arbor out and it has 2 TP1 62032 ball bearings. Unfortunately in the process I also broke the BRACKET,TAPER REGULATOR (part #6285231). Unfortunately it looks like this part is no longer manufactured and I can't find it anywhere. I think I'm screwed.
Aluminum can be TIG welded by any competent machine shop. Check around. I've had stainless steel TIG'd and it's reasonable. That's your only solution if you can't find a part on Ebay....
Regarding the bearings (6203Z), I've heard Nachi is a good brand. Will these 6203-2NSE bearings work? They look to be the same size but wasn't sure if the "2NSE" are interchangeable with the "Z".
The difference in the numbers relates to the seals. The first portion(6203) is the size, "z" is a bearing with a metal seal on one side, and the other side open. It appears "2NSE" is a manufacturer specific code, appears to be a double sealed bearing. Without seeing the arbor arrangement to see why they used a single seal on the bearings I can say the 2NSE bearings will work, however the metal seal is there for a reason, to protect the bearing from the harsh working conditions. The other side is open to either allow the arbor to be lubricated, or to allow heat to escape(or both). So the 2NSE bearing may not deliver the same life that the Z bearing would, but it's likely to deliver all of the life you would need.
One trick I use on sealed bearings is to take a small pick and remove the seals, wash the crappy grease out of the bearing, and replace it with a high quality moly grease. When I had 5 ATV's to keep running for riding and racing with the kids every weekend, this was the only way to keep bearings in service for a longer period. To be fair though the regular power washing contributed a lot to bearing failure as much as anything else.
as mentioned, the Z suffix is a metal shield - the metal shield has a very slight gap/space between the inner race and the shield
a 'rubber' contact seal is typically RS - Nachi uses the 2N suffix. this type actually rides/contacts the inner race and is more effective at keeping liquids and fine dirt out of the bearing.
a single grouping of RS or Z indicates 'on one side'
2RS or 2Z indicates 'both sides' (also ZZ - each maker has its quirks)
C3 is the "clearance" - in this case slightly more clearance than "standard"
6203 is a very popular size - used by the billions in electric motors and alternators.
a seal or shield on one side only saves fractional pennies where the unprotected side is completely enclosed i.e. no dirt can get in. like two bearings pressed back-to-back or apart but at ends of a sealed tube.
the down side to 'one side' that is where there is a gap/space between the bearings (as when mounted in a tube) the grease can puddle in the middle space and starve the bearings....
I would recommend going with rubber contact seals both sides and the the explicit C3 fit if mentioned.
Nachi, NTN, SKF, Koyo - these are all good companies.
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