Bevel gear question

[JohnnyLisa]

Hello, everyone,
I need some advice regarding the elevation bevel gears in a BT3100. Elevating the blade causes a kind of "loping" motion when turning the crank handle - ie at regularly spaced intervals the turning motion gets alternately stiff and loose. It's not a major problem, just a little irritating that I haven't been able to smooth the action out. From experience with other table saws in this series, I know that the elevation mechanicals are usually very smooth.

While thoroughly cleaning and lubricating all the internals, I noted that the bevel gears have an irregular wear pattern on the teeth. The gears are apparently not meshing uniformly and this is causing excess friction - the deeper marks appear to coincide with the binding timing. I can't tell if the bevel gears are not aligned properly on their shafts or if the horizontal shaft the runs from the crank handle to the vertical gear is slightly out of round.

Can anyone tell me if the bevel gears can be adjusted? If I recall correctly, the vertical gear is held in place by a roll pin and the horizontal is held by a screw. Both fit snugly on their shafts with no play. I think the problem is with the horizontal shaft, but I'd rather figure out some way to be sure before fixing something that is not the problem.

Any ideas or help would be greatly appreciated,
John

[Black wallnut]

Sounds like it could be caused by a bent elevation shaft or mis-aligned hole in either gear. Without going out to the shop and tearing off my side panel I can't picture what else could possibly be a problem. Any way you can take some pictures and post them?

[Black wallnut]

Johnny, what have you found out?

[JohnnyLisa]

I haven't had a chance to look at it this week - that BT3100 is a replacement for a well worn BT3000 in my dad's old workshop a little ways from my house. I think the elevation crank wheel shaft is the problem, so I'll probably swap out its gear train with the one from the 3000. Might be able to get to it this weekend or Monday. I'll post what I find out when I do.

[JohnnyLisa]

Smoooooth blade elevation

I completely disassembled and reassembled my BT3100 Monday, and am happy to report that the blade elevation is now as smooth as the others I use. I now think the likely culprit was in some fine aluminum shavings in some of the threads of the elevation rod. With a good cleaning, the rod now moves smoothly and the bevel gears are no longer binding to overcome the resistance. There are no more shavings appearing when I run the rod up and down, so I think the motor mount threads are still OK. After reassembly, the elevation was uniformly pretty stiff, but I gave the shims, tracks and threaded rod a good dose of a non-silicone dry spray lube I found at Lowes and everything now seems to work great.

Now I can start on a mobile cabinet for it!

[LCHIEN]

good for you, glad it worked out.

[JSUPreston]

BTW: For those who don't know, John bought the BT31x from me. I've talked with him a time or two since. Great guy to deal with.

John, I'll admit you've got me stumped. I didn't cut any aluminum on the saw myself, so unless my FIL used it (which I doubt), I can't explain it. I am glad you figured it out, and once again I apologize that you ran into this snag.

[JohnnyLisa]

Hey, Preston!
The stray bits of aluminum in the elevation rod threads wouldn't have come from anything that was cut on the saw - I think they were left there by the motor mount lug that the rod rides in. It appeared that there were a couple of very, very fine slivers left over when the threads were cut into the lug and these were subsequently transferred to the rod threads. I think this is so because I found a tiny bit of said sliver hanging at the bottom of the motor mount lug threads. I can't say for certain that this was causing the binding because I lubed and adjusted several things at the same time, but it seems reasonable to me.

As I mentioned before, most people might not have thought anything was wrong with the elevation motion - I just knew from using other BT's that this one, while good, could be better. And now it is!

It was also good for me to break the saw down and reassemble it. I now understand how all the components fit and work together. If any problems crop up down the road, I won't be hesitant to dig into it and will have a much better idea of where to look for the source of the problem.

Thanks again for a great saw!

John