Bandsaw blade drift

[Carl Beckett]

Working through this now, and have read a number of posts and videos on the subject.

The question I have is about how 'sharpening' may affect blade drift?

I did sharpen the blade using a dremel with a diamond disk. I only touched the front edge/undercut of the tooth.

This is a blade that came with the machine, but I believe is a pretty decent resaw (3/4") blade. Was just 'dull'

It cuts well after sharpening, but now has a severe drift.

I am going through all the usual motions again, but does anyone have experience with drift after hand sharpening and what details may play into it? (was wondering if I held the dremel at a slight 'angle', it may have put a sharper edge on one side of the offset than the other, thus cutting preferentially.... or something like that)

Have seen a video where a stone was held against one side while running to dull that side a bit and even out the cutting - which then caused drift in the opposite direction.

[Edward Weber]

Yes, a dull or unevenly sharpened blade will cause the blade to follow the path of least resistance and wander in the cut, drift.

[Richard Coers]

When you touch the face of the tooth, it also changes the set slightly. If your position had a slightly different angle when doing left and right set teeth, you probably have a different geometry on each side. I sharpen by hand to cut up turning blanks, but would never use that blade for accurate cutting. Original blades are notorious for low quality steel and hardness.

[James Jayko]

Stupid question...but why not try a new, sharp blade? You're talking ~$40 vs hours of troubleshooting.

Just saying...

[Doug Garson]

+1 on the new blade, save the sharpened blade for rough cuts, get a good resaw blade and use it for straight cuts, rips and resawing only.

[Carl Beckett]

It is on a Laguna LT18

158" x 1" blade.

They are not 'that' cheap (and yes am preserving my resaw king, also not cheap)

Recently got into some exotics which dulled every cutting tool I had in no time. Never did figure out what the wood was (a separate post on that a while ago), but others here have successfully sharpened and so I am giving it a try. It cuts great now, but drifting too much. Again I only touched the leading edge/undercut. But I am not confident it was exactly 90 degree/square to the blade thickness. (not sure the terminology, but would mean a side shearing action at the cutting edge)

Just wondered if anyone here who resharpens have had similar experience and could share the secret. Ultimately I will be resharpening the resaw king also, since it is an older one with ultra thin curf (sending it in last time was about $70 plus shipping)

Derek et al have a fixture they use on the saw itself, I may try that to square things up and see if it was grind angle related. Or as suggested perhaps tooth set needs tuned as well although I havent read of anyone doing that.

[Carl Beckett]

Did find a 3d printed piece to convert a chainsaw sharpener to work with bandsaw blades. The sawmill guys use these (and I have an un-used chainsaw sharpener it turns out). Do not believe it will work well for the carbide RK though.

[John TenEyck]

I use a modified chainsaw sharpener to sharpen by sawmill blades, but the wheel is pretty coarse and not suitable for blades on my shop bandsaws. The sharpener like Derek and I use for our shop bandsaws is far superior for that task. It uses a small diamond wheel on a Dremel. The version Derek uses touches the top of the tooth, the one I now use touches the front of the tooth.

If you are sure the blade is centered on the upper wheel, I wouldn't spend a lot of time trying to figure out why the blade now drifts. It does, so I'd resharpen it after making a fixture to guarantee the Dremel tool is square to the face of the teeth.

John

[Tom Trees]

A suggestion I've read before which might be worth checking is.. hand turning the wheels and seeing if the teeth might scuff more on one side,
through a piece of timber which was partially cut beforehand.

Be interested to see some recommendations on a setting tool for bandsaws.

Tom

[Ken Fitzgerald]

Carl,

No offense but you have answered your own question with your initial statement. If the blade was dull but didn't have drift before you sharpened it, and now after sharpening it, it does drift, that pretty much states and proves that there is a "set" difference between teeth that happened during the resharpening process. Absolutely, improper sharpening can cause drift.

[Jimmy Harris]

A couple of things might have happened. You might, as you suggested, held the Dremel at an angle, and unbalanced your blade. So now it cuts more on one side than the other, thus the drift. In which case, the fix it to sharpen it again. Or, since the Dremel rotates in only one direction, you might have put a burr on that side and now it cuts more off that side. If so, it might come back to straight over time, after you've cut a few boards or so. Enough to wear off the burr. Or you can try to "stone" the side it's pulling towards to smooth that burr off.

[Tom Trees]

Odd that there's never mention of setting teeth from the folks who sharpen their own (for the bandsaw, that is)
I guess there are hand setting tools which might do the job, for say 3TPI blades?
Something like this perhaps?
Screenshot-2022-12-5 Der Sägemeister vom Gampenpass Der Letzte seines Standes - YouTube.jpg

[John TenEyck]

Odd that there's never mention of setting teeth from the folks who sharpen their own (for the bandsaw, that is)
I guess there are hand setting tools which might do the job, for say 3TPI blades?
Something like this perhaps?
Screenshot-2022-12-5 Der Sägemeister vom Gampenpass Der Letzte seines Standes - YouTube.jpg

I watched several of those videos. Good stuff.

John

[Steve Demuth]

It annoys the hell out of me that I can't resharpen bandsaw blades, because I insist on having mine super sharp. You simply can't resaw reliably on a small saw with their limited tension, without very, and very uniformly, sharp blades.

But every solution I've seen in the youtube woodworker space has the same two limitations: no way to deal with blade set (as you point out), and not feasible on blades with variable tooth spacing.

[Richard Verwoest]

So why not mark a tooth, then stone one side of the teeth one full rotation. Then make a test cut. If there is still drift, repeat.

Richard