Speaking of "belt tracking"....

[J Tiers]

There has been discussion of tracking on belt sanders. I found a completely different version of mistracking today.

Went to use the Atlas bandsaw, and it was making an odd noise.

Picked up the part I was sawing from the "table", and found that the saw blade had decided for no discernible reason to jump forward about 10mm and start to saw the front of the table slot. It was forward partly off the wheels, out of the guides, and generally way out of position, starting to nibble on its own driveshaft. I have no idea why it did that.

I fiddled about with the guide rollers for a bit, and it went back and caused no further issues. I did nothing particularly interesting with the guides, loosened them, moved them out, then moved them back where they had been, and tightened them up again. The blade then went back where it should be, and caused no further trouble while sawing.

Very odd. I really do not like things that I cannot find a definite cause for, because I haven't a clue if I actually fixed the problem or just fixed a symptom.

No, there did not seem to be any excessive accumulations of swarf on wheels or guides rollers, or anywhere else. I had thought of that as a possible cause, but saw no such.

[Gary Paine]

I see that if withdrawing from a cut or dislodging from a bite in at times, but have never seen it if putting cutting pressure on a workpiece.

[J Tiers]

I think it had done ut between the time I hit the switch and when I applied pressure on the workpiece. Possibly some of the shift occurred as I was starting the cut. I would have noticed a 10mm shift if it had happened during the cut.

When I noticed something wrong, I had only about half a mm of cut completed.

[brian Rupnow]

My bandsaw has two adjustments on the top wheel. One is simply a tension device that increases the distance between the top and bottom wheels to tension the blade. The other adjustment actually tilts the top axle, which I assume is to adjust the tracking of the band on the wheels. I can see it doing what you are talking about if that "tilt" mechanism came loose and moved.

[J Tiers]

I do not think this has a tilt adjustment, I'd have to check the manual.. In any case I did not adjust it, either before the problem, or before it went back to normal.

[J Tiers]

Well, it did it again this evening.

The precipitating event was a bit of cut off material that bounced into the slot where the blade passes thru the table, and was kicked back out onto the table (it did NOT drop down or get caught in rollers etc). But right when it was kicked back out, the blade slipped out in front again. I am going to have to take it out and check everything. The little piece that the blade does not seem like sufficient reason for it to do that.

Really odd, because I used it not that long ago, and all was fine. Never has done this before in the nearly 20 years I have had it. Now twice in one day.