Bandsaw Drift

[Jerry Thompson]

If I correct BS drift for one width blade will it hold true for other widths? This is for re-sawing various types of lumber. I have tried to use the pivot device on the fence but I am a klutz in that dept. and hope to do better with a drift adjusted fence. The saw is a 14" Delta, no riser and I will be using Timberwolf blades.
Jerry

[Don Wacker]

Every blade will have a different drift.

Don

[Chris Tsutsui]

Unfortunately I have to adjust drift angle every time I put on a different blade.

[Roger Bullock]

I was having poor results with resawing recently. Read a couple articles on bandsaw setup to see if I was missing something. Without changing the blade, I cleaned the drive wheels, added shop vac dust control and squared the blade to the table. Improved resawing a bunch. Might try it for yourself.

[Jerome Hanby]

I was having poor results with resawing recently. Read a couple articles on bandsaw setup to see if I was missing something. Without changing the blade, I cleaned the drive wheels, added shop vac dust control and squared the blade to the table. Improved resawing a bunch. Might try it for yourself.

That makes a lot of sense. maybe it's just my lack of experience, but it sure seems most likely to me that drift would be caused by come degree of misalignment. maybe most saws just can't be adjusted well enough to completely do away with it. May have something to do with the size of the saw too. I see very little drift with my Shopsmith 11" saw using Timber-wolf blades, it'll be interesting to see what happens when I get my 14" Delta/Rockwell with the riser block refurbed and online.

[ian maybury]

Correct saw set up is clearly a fundamental, and blades definitely vary (sometimes dramatically) from my experience. That said it also seems to be the case that if the saw is big and heavy enough to really tension the blade that quite a bit of the pernicketiness goes out of the situation....

ian

[David Kumm]

Ian is right on. Generally if the saw has crowned tires and is set up correctly there will be minimal drift and it will be the same for each blade as each will seek to ride to the crown. Flat tires may act differently but much of the drift is the result of compensating for alignment issues. Dave

[Ben Hatcher]

Completely agree that setup, and proper tension, remove a bunch of drift problems. Blade sharpness does, too. If my blades start to drift on me, I know that I probably have a few dull teeth on one side, or one with more set than the others.

[Rod Sheridan]

I don't use a drift fence, the fence on my saw is set at right angles to the wheel.

The blade is adjusted for drift by shifting it slightly forward or backwards on the wheel, by tipping the upper wheel. Once the blade is tracking properly (parallel to the kerf) I adjust the blade guides to their normal positions, during the tracking adjustment they're set far away from the blade.

I've never understood the adjust the fence idea, do you then have to adjust all your bandsaw jigs too every time you change blades?

Regards, Rod.

[Jerry Thompson]

I don't understand "the fence on my saw is set at right angles to the wheel." I should say how does on do that? "Once the blade is tracking properly (parallel to the kerf) I adjust the blade guides to their normal positions, during the tracking adjustment they're set far away from the blade." Would I saw a kerf with the wood against the fence and adjust the wheel to cut parallel to it?
I am a picture guy and written directions sledom help me. Thanks for the input and in advance for more help.

[Kent Chasson]

Ron, do you keep adjusting the tracking and bearings as your blade dulls?

When resawing for any length of time, I almost always have to re-adjust for drift. And not because the blade is wandering around on the wheel.

And I'm curious what kind of jigs are you using? Never seen much in the way of bandsaw jigs. The only jig I've ever used on a band saw is for pattern cutting, holding the work a bit proud of the template prior to routing the final shape. But that's somewhat of a kind of freehand operation so tracking isn't much of an issue.

[ian maybury]

What Rod is saying Jerry is that because the wheels are crowned or cambered (have a slight hump in the centre) the alignment of the blade changes relative to the rest of the saw as you change the settings to move it from running on say the back of the wheel to running on the front.

Which tends to mean that if you want the blade to keep cutting in a particular line relative to the saw or fence you need to track (by tilting the top wheel) it so that it runs on the same part of the wheel crown as it was running on when it was set up.

This of course changes or no longer holds if e.g. the blade gets blunted a bit more on one side than the other and no longer cuts straight....

ian

[david brum]

If you are on the online FWW site, Michael Fortune has written some fabulous, no BS articles on how to set up band saws. There are videos as well. After I set my saw up as he describes (a couple of years ago), I haven't had to move my fence angle in order to get good resawing. http://www.finewoodworking.com/FWNPDF/011173066.pdf

[lowell holmes]

+1 for the Michael Fortune article.

[Rod Sheridan]

I don't understand "the fence on my saw is set at right angles to the wheel." I should say how does on do that? "Once the blade is tracking properly (parallel to the kerf) I adjust the blade guides to their normal positions, during the tracking adjustment they're set far away from the blade." Would I saw a kerf with the wood against the fence and adjust the wheel to cut parallel to it?
I am a picture guy and written directions sledom help me. Thanks for the input and in advance for more help.

Yes Jerry, I put the blade on the saw with the guides not touching and use the rip fence to cut a couple of inches into a piece of wood. The blade will be twisted slightly in the cut, I adjust the tracking so the saw blade is now centered in the kerf. Move the fence a bit, recut and check that the blade is centered. Adjust the guide wheels to almost touch the blade and you're good to go.

The table is adjusted so it's square to the wheel once ( when assembling the saw) by using a framing square. Stand the square on the table so it touches the left side wheel, measure the distance from table edge to wheel edge, repeat for the right side of the wheel, both measurements should be the same.

I have some jigs that ride in the mitre slot so adjusting the fence for drift is useless for me.

I was taught in industry to adjust the blade, that's what the adjustment is for.................Regards, Rod.

[John Dougherty]

Misalignment will have a very definite effect on drift, as will blade tension. I use a RIGID BS14002 and find that after changing a blade, I have to carefully alignment the blade on the crown of the tire. Once the blade is positioned and tensioned cut is very close to drift free. Blade tension however will still have some effect if it is too low. During cutting the blade will heat up causing the work tension to loosen. You need to watch that effect as well. If you force too much cut, the blade start to drift regardless of how well tuned the saw when you began cutting.

[David Hawxhurst]

rod,
where do you place the blade on the wheel? teeth hanging off or just place the blade in the middle of the wheel? are your wheels flat or crowned?
your method seems like the one to learn. already squared my table to the wheel.

[Rod Sheridan]

Hi David, my saw has crowned wheels.

I start with the blade tracking in the center of the wheel when I rotate the wheels by hand.

After that initial tracking I close up the doors and apply power and do the test cuts.

Regards, Rod.

[Ken Shoemaker]

Rod,
I think alot of us are following this thread. I for one am going to try this on Saturday. Blade drift sucks!!

[Jerry Thompson]

Thank you Rod. I have looked over my saw and I find the tires and all else appear in good shape. I plan on having a go at it in the next few days. I am just getting back to doing wood work after having a bad shoulder and then surgery. That and I have developed a case of being very lazy. I am up to flaring my nostrils 50 times a day and should be up to speed soon.
Jerry

[Bob Wingard]

rod,
where do you place the blade on the wheel? teeth hanging off or just place the blade in the middle of the wheel? are your wheels flat or crowned?
your method seems like the one to learn. already squared my table to the wheel.

Center the SOLID portion of the blade on the tire. Ignore the teeth. If the blade is dead center on the tire, there should be no drift. The further the blade is off center, the worse the drift will become.

[David Hawxhurst]

thanks rod.
my bandsaw has flat wheels so hopeful this will not change the procedure. i will give this a try, only thing to loose is drift.
i've always heard that even with flat wheels that 1/2" and bigger blades should hang the teeth of the edge of the wheel. sounds as this may not be true.

[Rod Sheridan]

David, if you have non crowned wheels you should have the teeth off the front edge of the wheel...............Regards, Rod.

[David Hawxhurst]

thanks. i'll play with this over the weekend and see what happens. i'll try keeping the teeth off the front edge and play with the tracking to elimante drift.

[Curt Harms]

I subscribe to Rod's technique as well. I've also heard to use blades intended for resawing for straight cuts only. I keep the second one for rough work. Doing any significant curved cutting will cause more wear to the teeth on one side of the blade than on the other. Now the blade will drift because the 'cutting load' is not centered, one side of the kerf is working harder due to teeth being more dull or set is no longer equal on both sides. So I only use 1/2" blades for straight cutting & resawing, 1/4" blades for curves. If I used a band saw more than I do and cut relatively shallow curves I could keep two 1/2" blades, one for straight cutting and one for curved. The advantage would be easier changeover changing one 1/2" blade for another 1/2" blade vs. changing 1/2" blade for a 1/4" blade. Blade condition matters as well. I have 2 1/2" blades. One resaws very well, another that looks identical to my naked eye doesn't resaw well at ALL.

[Phil Thien]

thanks. i'll play with this over the weekend and see what happens. i'll try keeping the teeth off the front edge and play with the tracking to elimante drift.

I previously owned an Inca with flat wheels/tires, and was never able to eliminate drift.

The last two bandsaws I've owned have had crowned wheels/tires, and tracking the blade in the center of the top crown eliminates drift.

[John Lanciani]

Its important to remember that almost all of the bandsaw tuning articles are written for saws with crowned tires. A saw with flat tires will not respond to tracking and drift adjustments like a crowned tire saw. With flat tires you want to run the teeth off of the front of the tire (if the blade is wide enough) and adjust to how the blade cuts. If you run a blade with the teeth on the tire you'll tend to flatten out the set of the teeth on the inside and make the drift worse. I'm fortunate enough that I only use my big saw- MM20 w/ 1" trimaster 2-3 TPI carbide blade- for ripping and re-sawing and I've never had to deal with drift. I just set the fence to the lead angle of the blade when I installed it and never gave it a second thought.

My personal opinion is that a big cause of "drift" is due the the proliferation of "low tension swedish silicon steel" blades. On my small saw - 14" delta- I use 1/4" 6tpi Lenox diemaster II bimetal blades tracked on the center of the wheels and there is zero drift from day one of a new blade until it goes in the trash can. Whatever lead angle they start with is the same that they finish with.

(I'm always amused by the people who will insist that they need $100 tablesaw blades to build bird houses will refuse to spend $35 on a decent bandsaw blade. There really is a difference, you owe it to yourself to try.)

[Cody Colston]

I find it odd that every article or book I've read about bandsaws, written by supposedly bandsaw experts, describes how to adjust the fence to account for blade drift.

Perhaps if they only read SMC, they would discover that blade drift is avoidable. Maybe some of the experts here could write a book on bandsaw set-up and use.

Surely woodworkers everywhere would snap it up once they realized they had been misled all these years about blade drift and how to compensate for it.

[David Hawxhurst]

no way i'm spending $100 for a table saw blade. if my router table wasn't attached to my table saw i would get rid of it. the more i use the bandsaw the more i like it. i'm by no means very knowledgeable on bandsaws. the european big bandsaws usually have flat wheels and non adjustable fences and miter slots on the tables, so there must be a reasonable way to minimize or eliminate drift. the tracking seems to be the way. however it seems that here there are several people have not had success with eliminating drift with flat wheels. i will still try.

[David Kumm]

Don't forget that tension plays a part as well. I run my Starrett bi metal blades at 30000 which pretty much eliminates most problems and also makes the guides kind of irrelevant. Dave

[Jim Finn]

I had similar drifting issues so I tossed out the Timberwolf blade and got a woodslicer blade. All the difference in the world. I now re-saw 8" - 12" wood using a tall re-saw fence and I do not adjust it for drift. Works like a charm.

[glenn bradley]

Correct saw set up is clearly a fundamental


Ian is right on


Completely agree that setup, and proper tension, remove a bunch of drift problems.

I'm in the Ian/Dave/Ben camp but, this may be due to my experience. I've only had four different bandsaws but, given proper setup, all have performed well within their design limits. My current pair are a Grizzly 17" and a Rockwell/Delta 10". I change blades on each often (1/4" through 3/4" on the larger saw and 1/8" through 1/4" on the smaller) and require no adjustment other than guides. I run Timberwolf blades but, have run others as well. If this has been dumb luck all this time I willingly accept my horrible luck in Vegas as an exchange :D.

I don't resaw veneer thicknesses under a fat 1/16" but do cut tall stuff pretty regular on the larger machine. Perhaps having that much blade in the stock helps but I don't notice issues when doing fussy lower-height, fence-guided things like tenons either. Both machines have crowned tires. I imagine that the machines design and use come into play. Drift is obviously a reality in some designs; they make expensive fences just to compensate for it. Wider blades under higher tension benefit from flat tires (greater surface support). It may create a slanted view of things when comparing a machine with a design focus on curves that also does general resawing to one with a focus on resawing that can be used for other things(?). I imagine a resaw machine gets setup for the blade and then run till it is time to change out the blade. My home-shop machines do multiple duty and are changed out frequently. I also imagine that neither of them comes close to the performance of a more task focused design.

As for visual aids for a crowned tire saw:

[Don Wacker]

I think every saw is a little different and the issue is folks want to group them as just "bandsaw". I dont even use the guides on my saw. I keep them adjusted as far away from the blade as the adjuster will allow. On my old saw I had to spend money on expensive guides, add shims and mess around with every possible adjustment until I could finally get it to cut a straight line. Expecting a little 14" band saw to resaw like a 24" saw is asking a bit much. The little saw can be made to cut pretty good but in the long run they just are not made to do what people are asking of them.

Don

[Mark Engel]

I find it odd that every article or book I've read about bandsaws, written by supposedly bandsaw experts, describes how to adjust the fence to account for blade drift.

Perhaps if they only read SMC, they would discover that blade drift is avoidable. Maybe some of the experts here could write a book on bandsaw set-up and use.

Surely woodworkers everywhere would snap it up once they realized they had been misled all these years about blade drift and how to compensate for it.

Must be a HUGE conspiracy.