Trying to fix curved cuts w/o new bar or chain

[muddy42]

If you do bar maintenance little and often with a flat file and a square you can keep bars going for ages. But I think that chain and bar are beyond rescue.

 

[Sidecarflip]

Make sure the sander table is dead on 90*. I use a quality machinist sq and re-check it often.
I’ve used a delta 1x30” belt sander for decades…60g Zircon belts.
I’ve redone dozens of bars the owners thought they’d squared up.

The problem with using a disc sander for bars is it will want to pull/push…up cut and down cut at the same time. A vertical belt sander is a lot better.

That depends entirely on the size of the abrasive disc, as well as the grit, the table (which has to be at 90 degrees to the disc and how you gold the bar when grinding it. I use a commercial 16" psa disc grinder and keep the bar securely held against the table at all times. How I re-rock a flat bar.

 

[Sidecarflip]

Problem with had filing versus machine grinding is... No matter how good you think you are at hand filing, you will never get all the cutters the same, an impossibility whereas with machine grinding. the grind depth is set mechanically and is totally repeatable across ALL cutters. Not only will the teeth vary but so will the rakers as well as the tooth angle.

 

[Kdavis2685]

Are you using a file guide? It may be worth mentioning that just because the top of the teeth are filed back the same distance, all the angles can still not match, causing crooked cuts. It can be a tendency to get the gullet deeper when sharpening from one side, vs the other. It is common to have one set of side cutters have a more aggressive chisel angle, not top plate angle, but actual chisel angle, ie like a razor blade vs axe. Check that. Or put a new chain on your tuned up old bar, and see what happens. That will tell you if it's your sharpening vs your bar.