My problem (technical) with the SuperSaw
I hope that I can help others with SuperSaws and I hope that (maybe) someone from Jet reads this forum. The blade raising belt on my supersaw, as with many others, recently stripped. I had to get a new belt and a new pulley from Jet (good customer service). I had to drill out the set screws on the old pulley.
With the belt replaced (by the procedure in the saw instructions!!!!), the blade raised auccessfully, but with difficulty, for only a few days, then the timing gear that drove the blade raising cog belt spun on the shaft.
After a few blue words and a little disassembly, I found the real original problem that made the belt strip. The bushing for the worm gear shaft that drives the blade raising had galled against the shaft. It would not turn. Galling means that the rubbing of the shaft inside the bushing has “welded” metal from the shaft to the bushing and the rotation has messed up the shaft and the bushing. After stoning and honing down the shaft and cleaning up the ID of the bushing with a butterfly, the blade now raises and lowers OK. I’ve opened up the clearance so I’m going to request (!!!) that Jet send another worm gear shaft and another bushing. Then, I’ll get a friend to ream the bushing before installing the new shaft and bushing.
To see if this is what stripped the blade raising belt on your supersaw, use a lever (short 2×4) to raise the motor and use wood blocks to hold it up and relieve the tension on the main drive belt.
With the blade raising cog belt removed, can you turn the worm gear shaft freely and easily by hand? If not, the bushing is misshapen and has galled the surface of the shaft. Call Jet and get a new one and demand a bushing that is not deformed!
The bushing is deformed because two flats are milled (or ground) on the OD of the bushing to allow adustment. My experience as a manufacturing engineer tells me that machining the flats on the bushing after reaming the ID deforms the ID of the bushing so that it contacts the shaft when assembled and galls the metal ultimately making the shaft almost impossible to turn and then stripping the belt as you try to turn it.
Not an unacceptable problem for a new product that is otherwise good, but I hope that Jet will fix the deformation problem and make good for owners of older saws. Are you listening Jet??
Replies
The belt on mine broke after 2 weeks. Took Jet 3 months, yes 3 months to get me a new one. Turn the handle gently near the upper and lower limit of travel. I've been doing this and haven't had a problen in the year and a half since I got the new belt.
The new belt that Jet sent me is a different numbered belt 0 off by one digit in the catalog number. It lists as being a better quality belt.
My belt stripped the cogs (it didn't break). I've decided that it stripped because of the problem with the mashed down end of the bushing where they milled the adjustment flats (on the worm gear shaft). The shaft and that end of the bushing were obviously galled and had been rubbing until they ultimately froze and had to be pounded out with a dowel and a hammer. If your belt fails again, lift the motor off the drive belt and try turning the worm gear. It should turn with little resistance or you have the same problem I did.
Honestly, I suspect that this gradual freezing of the worm gear shaft due to interference and galling is the cause of all the timing belt issues. I hope that Jet will fix this as it should be pretty simple to fix.
I've had the timing belt strip as well. My problem came from cranking the blade too high. The blade raising mechanism reached the upper stop. Jet sent me a new timing belt and at my request a second spare if this happens again (for free). This all happened Feb 2003, purchased the saw Dec 2002. I may see about getting one of the new timing belts to see if they are heavier duty. I can not disagree with your experience concerning the galling, it seems plausible. Did you take any pictures? It has been a while since I've been in the guts of my saw to remember the layout and all the parts.
Another solution that I am considering is to replace the timing belt with a small gauge roller chain. Finding sprockets to fit may be a problem. I am concerned about dust accumulation though.
Do you have the SS with the sliding table? Mine does and I can not get the sliding table in proper alignment. The table rises above the main table and drifts to the left (away from the blade) as it is pushed forward. This makes for some pretty ugly cuts and dadoes are impossible. I called Jet and they said the slide rollers were probably bent and sent me a new set. (This had to be a very expensive replacement. Heavy duty slide bearings.) After spending 3 hours replacing the bearings and realigning the table, the same problem was occurring. I have not had a chance to spend anymore time to figure this one out. Does anyone else have this problem?
Otherwise this is a pretty good machine.
I should have taken pictures. My reaction was also that I would rather see a chain and sprokets here. I'm still a little unconvinced about the timing belt.
I have the sliding table and could never live without a sliding table again. No problem with cuts: I've cut some plywood panels specificly to test the accuracy of the table and it works great.
You're right - It's a pretty good saw. If they fix some of the issues raised in the various forums, it will be a very good saw. Yesterday I ripped some 8/4 white oak that is like cast iron. No slowing at all. I use a Forrest WW II thin kerf to mitigate the lower HP rating. The Forrest: WOW!! WOW!! End cuts on white oak like glass; rips glue line clean. It seems worth all $100+!!
One lesson is to not buy a new product for a few years. Speaking of that, my very old Royobi AP10, the first portable planer, is approaching retirement. I really like the new DeWalt 2 speed planer, but forums all over have threads about shattering sprockets. I hope the Royobi can hold out until DeWalt fixes their planer!!
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