The Cellar - View Single Post - Building a bandsaw on the cheap from mostly scrap wood

glatt · 10-22-2016, 04:12 PM

Tinkered with the band saw for several hours today, but nothing to show for it.

The table is made of particle board, and I had cut through the plastic laminate top and bottom to make it the right size. This left an exposed particle board edge. That stuff can suck up moisture and start crumbling like nobody's business. So I found an old partial can of oil based varnish and sealed the cut edges of the particle board.

I made new tabs to go on the top cover, but didn't install them yet. It was a rare moment of clarity. The saw has a bit of a vibration to it, so I wanted to figure out what was vibrating and fix it before locking in on a cover size. You can see the motor shaking a bit too as the frame shakes.

I read in that Bandsaw book Foot recommended that you should align the wheels so they are co-planer and not rely on the crowned wheels so much to align the saw blade. So I got out my straight edge to fine tune that. I figured I might need to shim the wheels with some washers to get them perfectly lined up. When I lined the straight edge up with the bottom wheel, the top wheel was a full 9mm out of alignment further back. WTF? I have no idea how that happened. Did I measure the shaft wrong? Is it a metric thing with the layers of the frame? I don't know, but I do know that I need to fix it before I finish the cover. It's going to mess with the cover a lot to move that top wheel 9 mm forward.

I took the blade off the saw and ran just the powered bottom wheel. The vibrations were still there. I took the bottom wheel off and ran just the motor. No vibrations. So I got out my dial indicator and measured the pulley on the powered wheel. As I slowly rotate it, the needle goes 5 thousandths in one direction and then 15 thousandths in the other. The pulley is 20 thousands out of round. I wonder if that's enough to cause those vibrations? I bet it is. So I'm attempting to turn the pulley again to get it nice and round. I think when I turned it before, my chisel was just riding up the hump and then down into the hollow. I hold it fast to the tool rest more this time as I turn the bottom of the pulley.

So the saw is basically completely disassembled right now as I try to tweak this stuff.

10-22-2016, 04:12 PM	#312
glatt ™ Join Date: Jul 2003 Location: Arlington, VA Posts: 27,717	Tinkered with the band saw for several hours today, but nothing to show for it. The table is made of particle board, and I had cut through the plastic laminate top and bottom to make it the right size. This left an exposed particle board edge. That stuff can suck up moisture and start crumbling like nobody's business. So I found an old partial can of oil based varnish and sealed the cut edges of the particle board. I made new tabs to go on the top cover, but didn't install them yet. It was a rare moment of clarity. The saw has a bit of a vibration to it, so I wanted to figure out what was vibrating and fix it before locking in on a cover size. You can see the motor shaking a bit too as the frame shakes. I read in that Bandsaw book Foot recommended that you should align the wheels so they are co-planer and not rely on the crowned wheels so much to align the saw blade. So I got out my straight edge to fine tune that. I figured I might need to shim the wheels with some washers to get them perfectly lined up. When I lined the straight edge up with the bottom wheel, the top wheel was a full 9mm out of alignment further back. WTF? I have no idea how that happened. Did I measure the shaft wrong? Is it a metric thing with the layers of the frame? I don't know, but I do know that I need to fix it before I finish the cover. It's going to mess with the cover a lot to move that top wheel 9 mm forward. I took the blade off the saw and ran just the powered bottom wheel. The vibrations were still there. I took the bottom wheel off and ran just the motor. No vibrations. So I got out my dial indicator and measured the pulley on the powered wheel. As I slowly rotate it, the needle goes 5 thousandths in one direction and then 15 thousandths in the other. The pulley is 20 thousands out of round. I wonder if that's enough to cause those vibrations? I bet it is. So I'm attempting to turn the pulley again to get it nice and round. I think when I turned it before, my chisel was just riding up the hump and then down into the hollow. I hold it fast to the tool rest more this time as I turn the bottom of the pulley. So the saw is basically completely disassembled right now as I try to tweak this stuff.