Tony B

I have a Delta Contractors Saw.
When I crank the handle to raise and lower the blade in normal operation, there is no problem. But when I want to make Dados, the height adjustment is critical and the blade changes height all by itself regardless of how hard I tighten up the knob.
If I remove the blade insert and look down there (with power cord unplugged) I could see a nut on the backside of the height adjustment.
This nut is on the threaded part that makes contact with the worm gear. While cranking the height adjustment knob, the nut stays put MOST of the time. But then at a certain point, the nut starts spinning and in effect loosens the height adjustment nut.
If you own the contractors saw, you know exactly what I am talking about.
I'm sure there is a quick fix for this problem, so what am I overlooking?

Thanks in advance

Tony B

John in Tennessee

I have one and for once I may be able to find out for you. I have mine upside down on the bench. I'll check it out. I'll try and let you know tomorrow.

mmwood_1

Tonyb,

I was having a similar problem a couple of years back with mine. I replaced the washers in the front, behind the tightening knob. There was a fiber washer in there that I think got worn. I don't recall exactly what was there, but I know I replaced them, both in front of and behind the crank. And I know I have a serrated lock washer on it now also. It has never moved on me, unbidden, since.

__________________
mark

http://markmeyerwoodworking.com

cabinetman

You might first just remove the nut, and clean the threads and solvent wash the threads of the nut. Also, remove the outside tightening knob. and clean all the parts. If you see any overly worn parts, they should be replaced. There may just be debris, or oil from wood dust collecting in there.