Can't adjust blade height - no play in guide holder

[mgusg]

The blade height adjustment on my BT3100 gradually got more difficult until it wouldn't move at all. I disassembled the saw, expecting to find broken shims. Instead, I found that the shims were all there and in good shape. The problem is that the guide holder fits so snugly in the locker bracket that it can't move. I had to force the guide holder off - it's extremely tight. I cleaned the shims and the mating surfaces, but with the shims in place I would have to force the guide holder back on. There's no way this thing is going to move right now.

What could have happened? The height adjustment used to work. Is the guide holder supposed to fit so tightly and I just need to lubricate it? I've read that there are supposed to be some set screws to adjust something in that area but I don't see any or where they could be.

[Black wallnut]

If at one time your saw worked fine then I'd have to say that tolerances are not too tight. On the BT3100 there are not shim set screws which is why you could not find them. With the guide holder removed does the motor assembly move up and down?

[mgusg]

If at one time your saw worked fine then I'd have to say that tolerances are not too tight. On the BT3100 there are not shim set screws which is why you could not find them. With the guide holder removed does the motor assembly move up and down?

Yes, the motor assembly moves up and down until I attach the guide holder. So you think I just need to lubricate the shims? It seems too tight, but I suppose it needs to be pretty tight to be accurate.

[Black wallnut]

yes lubricate the shims and where they ride as well as the elevation screw with either candle wax or a good spray on dry lube (I use lock-ease brand)

[Brian G]

Check also the tightness of the nylon hex nut on the elevation shaft. If it's too tight, it will bind the gears and make elevating and lowering more difficult.

[mgusg]

I lubricated all of the mating surfaces and reassembled the saw. The blade goes up and down pretty freely now. It's not as good as new, but at least I have a usable saw again. Thanks for the guidance.

[LCHIEN]

I lubricated all of the mating surfaces and reassembled the saw. The blade goes up and down pretty freely now. It's not as good as new, but at least I have a usable saw again. Thanks for the guidance.

You'll want to keep the ways lubed and especially the elevation screw. One of the weak points of the saw is the steel elevation screw engages/drives the assembly with a aluminum threaded hole which being softer metal can wear. Most people don't wear it out but if there is exccessive load for a long time and insufficient lube, it can strip the threads.

[master53yoda]

You'll want to keep the ways lubed and especially the elevation screw. One of the weak points of the saw is the steel elevation screw engages/drives the assembly with a aluminum threaded hole which being softer metal can wear. Most people don't wear it out but if there is excessive load for a long time and insufficient lube, it can strip the threads.

My saw did strip the threads, it has never been bound up as long as i have owned it and one day as i was adjusting it up it just dropped. I heili-coiled a new thread and it has worked well. I also ran a die down the adjusting shaft because one of the threads had a bur on it and I think that bur is what cut the threads out of the motor mount. the adjusting screw is a 9/16 x 12 screw which is a standard size.