Blade won't raise or lower!

[DonHo]

The blade hight adjustment on my BT3100 just quit working(right in the middle of a project, of course ). I thought maybe the problem was with the adjustment wheel but I've checked that and I don't think that's the problem as the shafts all turn but the motor/blade just sits and doesn't raise or lower. The shaft that runs thru the motor bracket turns easily and I haven't had any problems with the blade hight adjustment working. I guess the threads(inside the motor bracket may have striped but it seems like I would have gotten a clue by the adjustment getting hard or sticking if that was the case. I had the blade lowered below table hight and when I started raising the blade it came up about an inch (moved very easy) then it just stoped moving. Any ideas as to what may be wrong AND/OR how to fix the problem would be most welcome.

DonHo

UPDATE:

Well, it was the the threads in the motor housing. I don't know if it came this way from the factory or this was what had been refurbished ( I bought the saw from Cummins almost 3 years ago ) but I think the bracket must have had the "helicoil" threads already and they came loose because close inspection revealed "threads" inside the threads on the shaft. They were broken and came out in pieces when I brushed the shaft with a brass brush. I've downloaded a couple of "fix" .pdfs from the old articles page and am in the process of tearing down the saw. The saw was very accurate right out of the box and I've had to make very few adjustments. I just hope I can get it back together and everything aligned properly again.
Thanks,
DonHo

[eezlock]

blade won't raise or lower?

Don, I don't know if this is the problem or not....have you taken a good close look at the motor/blade elevating shaft mechanism? I would check it VERY closely....may be clogged up with sawdust, dirt or any other foreign matter.
If you check and clean the shaft really well with a small stiff wire brush,
lubricate it really well and see if that helps. If that doesn't solve the problem
you may be loking at a stripped shaft mechanism...that will have to be removed/ repaired or replaced. It could be that the threaded portions
of the shaft mechanism are stripped internally and you can't see them very well until you disassemble it from the saw. Hope this helps....I have not had to replace me as yet...I keep it really clean and lubricated, trying to head -off
this type repair. I just looked in the BT saw manual at the blade raise/lower maecanism on page 33, it shows (2)
bevel gears, might want to check the set screws that hold them in place and see if they have loosened
up over a period of time.Also check the threaded hole that the elevating shaft passes thru it could be
stripped and is letting the shaft just turn around and doing nothing to elevate the blade. eezlock

[big tim]

If the treaded shaft that goes through the motor bracket is turning when you operate the elevating wheel and the thread on the shaft looks OK, it must be that the thread in the motor bracket is stripped. IMHO

Tim

[JimD]

The lever on the front of the saw could also be in the wrong position or in-between the two positions. I would check that first. If the threaded shaft is turning, however, then it is not that. Cleaning the gears is always a good first step. I have had the height stop working just because of sawdust packed into the gears (and I have a DC sucking the vast majority of the sawdust out of the housing).

You should have had difficulty raising and lowering before you stripped the female threads on the motor housing. Maybe you were unlucky. If the female threads are stripped, you can get a helicoil kit and replace the threads (check at an autoparts store). It will come with instructions but basically you have to drill out the old threads, tap in new oversized threads for the helicoil, and then thread in the helicoil. You break off the coil with a punch, I think, to lock it in place. Because the housing is aluminum it will not be hard to tap the threads. I think your biggest hassle will be removing the housing to get good access to work on it.

I hope it is just sawdust packed into the gears. It is a lot easier to deal with.

Jim

[Stytooner]

Also insure that the riving knife isn't installed too far back. This would cause a bind too.
It may also help to grab the blade and lift while turning the handle. You must make sure the saw is UNPLUGGED first!