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Bandsaw Blade Runoff
Posted: Sun Feb 08, 2009 10:13 am
by meredj
I have adjusted and replaced the bearings installed a new half inch blade but the blade does not sit in the middle of the rubber on the wheels. It tends to move to the front and slip off. What do I need to do to correct this problem. I also have a problem with the aluminum table insert keeps bouncing after a piece of wood in cut and before I can turn the machine off it will bounce out and catch the blade and pops the blade off. Any help appreciated. I have the original rubber tires and the steel table.
Posted: Sun Feb 08, 2009 10:51 am
by Bruce
Did you back the bearings/bushings away from the blade before adjusting the tracking? You must do this or you won't be able to get the tracking right. And don't forget to do both the upper and lower bearings.
Bandsaw Blade Runoff
Posted: Sun Feb 08, 2009 11:00 am
by dusty
I'll attempt to answer the second question first because I think I can. The insert is held in place by either two or three spring clips. If these clips are old (lost their spring action) or missing, the insert will pop out. I have bent mine a couple time so that they hold better. You may need to replace yours. It is part number 5416173, Table Insert Assembly and sells for about $6.00.
Now for the hard part. The Shopsmith bandsaw is a bit different than most others in that the blade does not track in the center of the wheel and that the two wheels are not coplanar.
The blade should track somewhat toward the rear side of center on the wheel. If the blades have been left on the wheels tensioned, this may have caused the problem.
You want the top of the top wheel to be in a slight bit more than the bottom. Stand in front of you band saw (power off and unplugged). Grasp the top of the wheel with one hand and the bottom of the wheel with the other. Give a firm jerking motion to the wheel - pushing the top away from you while pulling the bottom to you.
Load the bandsaw with a blade, check that it is properly positioned on the wheels. Spin them by hand several revolutions. You should be able to see whether the band is tracking correctly or not. CAUTION: You already know that the blade can come off the wheels. This can be very hazardous.
You might want to do this first as a test to see what it is doing now. This would give you a point of reference.
Hope this helps!
Posted: Sun Feb 08, 2009 11:05 am
by meredj
If you mean when I lower the assembly to within 1 inch of the talble and adjust the bearing clearance to at least a 64th" from the blade, then yes I have done that. I also checked the upper limit with the assemby raised and I was at least a 64th there also. I do not see a front to back adjustment on the bearing near the tensioner though.
Posted: Sun Feb 08, 2009 11:13 am
by dusty
meredj wrote:If you mean when I lower the assembly to within 1 inch of the talble and adjust the bearing clearance to at least a 64th" from the blade, then yes I have done that. I also checked the upper limit with the assemby raised and I was at least a 64th there also. I do not see a front to back adjustment on the bearing near the tensioner though.
You said that the blade creeps off the wheels to the front (away from the tracking bearings). The tracking bearings will not prevent that. The bearings tend to prevent the blade from moving to the rear - the direction they would go if the upper wheel was properly positioned.
Extremely worn or hard tires can also contribute to your symptoms.
Posted: Sun Feb 08, 2009 11:18 am
by meredj
Dusty, thanks, I will go give that a try...
Posted: Sun Feb 08, 2009 11:43 am
by meredj
Flexing the top wheel, took care of the problem! And the insert that I have has no clips to keep it in place, I will order that and I will be good to go. Thanks so much for the assistance...
Posted: Sun Feb 08, 2009 12:01 pm
by shydragon
Wow, Dusty, great tip. I'll have to remember that. I'm not having any trouble with my bandsaw, but this needs to be bookmarked for possible future problems.
Posted: Sun Feb 08, 2009 1:58 pm
by dusty
meredj wrote:Flexing the top wheel, took care of the problem! And the insert that I have has no clips to keep it in place, I will order that and I will be good to go. Thanks so much for the assistance...
meredj,
I am so glad this worked out for you. This is one of the reasons that we all congregate here - to help one another. However, I suggest that you not count on this working for you forever. I would strongly suggest that you get in the habit of reducing tension on the blade when you quit for the day - especially if you know you might not be using the band saw again for awhile.
Now I know that some disagree with me but that is what I believe. Also, I don't practice what I preach here but then I use my band saw very regularly and I alternate blades probably a couple times a week - changing from a wide to a narrow blade back again.
Posted: Sun Feb 08, 2009 2:47 pm
by johnmccrossen
meredj,
You indicated that you have the older steel table on your bandsaw. Be sure you check with customer service before ordering an insert. The parts list indicates item # 502736 as the "old style insert for 2 1/2" hole". The aluminum insert on my older Magna BS is thin plate with no clips. It has a small nubb that aligns it with the blade and keeps it from rotating and it seems to stay in place pretty good. When you rotate the blade by hand (power off), make sure the blade does not rub on the insert especially at the blade splice. I also was wondering if your steel table has the small steel splice bar that screws on under the front of the table across the blade slot. This helps to stabilize the table and reduce vibration. Good luck and keep us informed about your progress with any equipment problems. Thanks, John McCrossen