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Rob Frink
06-21-2005, 12:28 PM
I have an older horizontal bandsaw which has just recently started throwing the blade off under heavy load. The tracking adjustment is maxed out and I think it is time to tutn the OD on the wheels. The back edge of the wheels has a lip to retain the blade. Do I machine a crown on the OD....or a Taper?....or just turn it flat?

Sincere thanks,
Rob

Otto
06-21-2005, 12:53 PM
Before you do anything, check the length of your blade. I had some new blades that were half an inch too long. Had the same problems as you. If that's not it, check the shafts of the wheels, one may be soft and will break off soon (had that happen too).

Otto

Alistair Hosie
06-21-2005, 01:09 PM
If you've max'ed up all the adjustments sounds then like the blade as said might be too big Alistair

3 Phase Lightbulb
06-21-2005, 01:53 PM
Turn the tension wheel handle as tight as it will possibly go. Once you can't tigthen the tension wheel anymore, gurnt really loud and turn it even more until you get blood blisters on your hands from turning the tension wheel. Then turn it one more full revolution. Then turn it one more 1/4 turn after you bandage up your hand.

The blade should stay on now..

That's what I needed to do to my Horz/Very saw http://bbs.homeshopmachinist.net//smile.gif

-Adrian

precisionworks
06-21-2005, 02:29 PM
One wheel, usually the driven wheel, will have some sort of tilt adjustment so the blade rides just under the flange. Dake suggests 1/16" as the correct clearance.

What type of tracking adjustment does your saw use?

------------------
Barry Milton

[This message has been edited by precisionworks (edited 06-21-2005).]

jstinem
06-21-2005, 02:31 PM
After you double check the length of the blades then check the shaft and bearing on the top wheel. My 4 X 6 bandsaw has a very short shaft and bushing with no provision for oiling it. When the shaft and/or bushing are worn out no amount of tighting will keep the blade on.
Hope this helps
Joe

Paul Alciatore
06-22-2005, 07:50 PM
If the blade is or has been kinked in the past, it may not track properly. I used a bi-metal blade for almost two years till it crashed one day. It didn't break and I straightened if out fairly well. I couldn't see the kink any longer. But it would not stay on the tires. I tried several times and finially had to replace it. New one worked fine.

Paul A.

J. R. Williams
06-22-2005, 08:13 PM
Rob
I agree with an earlier post, the problem is in the bearings/bushings. It probably has an oilite bushing on both wheels that need replacing. I had a similar problem with an older saw and bored out the return wheel and installed two ball bearings along with a new shaft. The drive wheel received a new bushing and a new shaft. The drive wheel's hub was turned to fit a large diameter, narrow, ball bearing unit with an overhanging support. That solved the tracking problem. Check the Home Metal Shop Archives for my article on the repair.

J.R. Williams

SJorgensen
06-22-2005, 08:24 PM
Try this answer out because I solved this problem on another horizontal bandsaw only yesterday. You should have two sets of roller guides. Each set has one back roller and two guide rollers that pinch the blade. Most saws have no provision for adjustment of these two pinch rollers and theoretically they are set to roll exactly parallel with the bandsaw blade. The problem is when a slight bend sets these rollers with a slightly different plane. If it is slightly in one direction the rollers will tend to push the blade out as they roll. Believe me that if you set it slightly in the other direction the rollers will tend to pull the blade back against the back roller as nature intended. Just a slight angle is required and you'll see that blade suck back right where it should be. If the problem is with the main tires I would recommend removing the roller guides and adjusting the alignment of the wheels until the blade rides perfectly. Perhaps one of the wheels has moved out due to a loose set screw or a worn bushing.

Good luck.