Bandsaw Blade Tracking Adjustments Etc.

[dusty]

Check the upper wheel cant. Lay a straight edge against the upper wheel and observe the amount of 'clearance' between the straight edge and the lower wheel. It should be about 1/4". The back edge of all blades should 'ride' on the upper wheel about 1/4" from the back rim(1/8" from the back edge of the tire?)

'Something' is causing the lower guide bearing to exert sufficient force to cause it to skew on the single lower guide bearing surface.(IIUC)

A 25 degree twist seems unusually extreme to me. Are you tensioning the blade correctly?

I'm reading this thread (again) this time looking for what we have missed. The backup bearings (guide bearings) can be backed off completely to eliminate them as the cause of the twist. I'd consider getting them completely out of the pictures to see if that eliminates the twist.

[dusty]

Define 'wiggle'. In/out as in warped? Sloppy on shaft? Arm moves?

Tension set 'properly'.

I am having a difficult time visualizing a 25 degree twist unless the blade is somehow bent.

Has it been stated where tension is set. This being a 5/8" blade, the tension is set quite high. Low tension would allow a "twisty" blade.

[dusty]

I just checked a picture I have of the upper wheel and I don't see any holes.

ok so this was me being stupid over lunch trying to figure out how to put a straight edge on the upper wheel please only laugh a little at this newbie.

oh hell laugh all you want I can hear you. love the internet.

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You might want to tilt the table so that you can get a clear line from top to bottom of the wheel. I put the straight edge against the ends of the two wheel shafts and just eyeball the gap at the wheel perimeters. The gap at the top should be the greatest. The gap at the top and bottom of the lower wheel should be close to equal. The gap t the top and bottom of the upper wheel indicates the cant. The gap at the top being the greatest.

You can spin the wheels to view wobble (the gap size changes) if there is any.

[dusty]

Ok so here is another video to try to show the wobble. I didn't even think to check for wobble like what Dusty suggested until now.

http://youtu.be/3WNp65TaHPA

thanks

Caleb

I know you hesitate to do this and there is good reason to hesitate but I would setup to view the wobble that you highlight in your video and then check it under power. Does it wobble when properly tensioned and powered?

I would also do this test with the guide bearings backed off or removed.

I'll be tuned in to see how this whole thing works out. I hope you solve your problem soon and with no expense (other than a new blade).

This following video shows just how stable the upper wheel is. Do not judge the degree of cant from these images without noting the distance that the straight edge is away from the axles. The lower wheel is not shown well but the gauge is equal distant from both the upper and lower axle.

[JPG]

I noticed in the video that the tension was set 'low' and that the blade was likely a 5/8" or at least a 1/2".

There was no evidence of blade twisting even with low tension.

The lower guide bearing and the upper guide bearings MUST be in place. The blade guides may be retracted and it allowed to 'run'. The upper guide bearing should normally not contact the blade.

[dusty]

I noticed in the video that the tension was set 'low' and that the blade was likely a 5/8" or at least a 1/2".

There was no evidence of blade twisting even with low tension.

The lower guide bearing and the upper guide bearings MUST be in place. The blade guides may be retracted and it allowed to 'run'. The upper guide bearing should normally not contact the blade.

If you are commenting on the video I posted, the tension is less than it should be for the blade I was running but that was on purpose. I did not check the backup bearings but I do not set those according to the book. Yes, there was no twisting going on.

[JPG]

I add this as a clarification(hopefully) of a way to verify the upper wheel 'cant'.

The band saw is laid on its back so the straight edge is positioned by gravity. A vice grip pliers is clamped to the 'lower' end of the straight edge and holds the straight edge by way of it acting as a pendulum.

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The straight edge rests against the 'top' and 'bottom' rim of the lower wheel as well as the lower wheel hub(avoiding the end of the shaft)

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The upper wheel cant is apparent by observing the approximate 1/8" space from the upper wheel rim bottom and the approximate 1/4" space between the upper wheel top to the straight edge. The straight edge does not contact the upper wheel hub.

The proper cant is indicated when a 1/4" properly tensioned blade has it's back riding 1/8" from the back edge of the tire.

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The last two pix show the straight edge position relative to the hubs.

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The blade is not tensioned in these pix. The band saw is the same as that reassembled above. <<<< Whoops! It is the bandsaw from the reassembling thread, not this thread!

[trainguytom]

Over time, I think I have done all of the above steps & never documented what I did. Thanks a TON for this post. It puts it all together for a great reference.

[caleb]

should I just removed the bearings top and bottom? and leave the auto backup bearings by the tension adjustment.

Caleb

[caleb]

I will run a straight edge on the sides of the bandsaw wheels and see what there is to see.

as for the posts above where people mention to back of the backup bearings I don't see how this can be done as the bearings are in set location front to back. the only one that is adjustable is the upper one.
which doesn't touch the blade.

Let me restate I reall appriciate all the help you guys are giving me.

Caleb