Bandsaw thin strips and drift...

[FS7]

I like to use thin strips in my cutting boards both for accents and for curved inlays. I have a few designs that use varying thicknesses (for gradient effects) as well.

What I usually do is take 1" or 1 1/8" thick strips of lumber and resaw them to whatever thickness I want - 1/16" or so for curved inlays and whatever I need for others. For the most part, setting the blade guides as low as possible above the work eliminates drift, since the blade can't really move that much in that amount of space.

However, sometimes I end up losing a strip to drift. By that I mean I have a bunch of 3/4" pieces that I intend to mill into three 3/16" pieces each and one of them only lets me get two instead of three because of excessive drift. I know drift is a problem with most every bandsaw, but I am confused as to why it happens on occasion instead of consistently. It's the same board, so it should be a relatively consistent thickness. I think it's a relatively consistent feed speed as well.  

I have never had a problem cutting thin strips on the tablesaw, but that's not exactly efficient when you're cutting strips half the thickness of your blade (67% waste). I am just not sure as to why I always end up with the occasional drift cut. Is this something I just need to deal with?

[mike4244]

I like to use thin strips in my cutting boards both for accents and for curved inlays. I have a few designs that use varying thicknesses (for gradient effects) as well.

What I usually do is take 1" or 1 1/8" thick strips of lumber and resaw them to whatever thickness I want - 1/16" or so for curved inlays and whatever I need for others. For the most part, setting the blade guides as low as possible above the work eliminates drift, since the blade can't really move that much in that amount of space.

However, sometimes I end up losing a strip to drift. By that I mean I have a bunch of 3/4" pieces that I intend to mill into three 3/16" pieces each and one of them only lets me get two instead of three because of excessive drift. I know drift is a problem with most every bandsaw, but I am confused as to why it happens on occasion instead of consistently. It's the same board, so it should be a relatively consistent thickness. I think it's a relatively consistent feed speed as well.  

I have never had a problem cutting thin strips on the tablesaw, but that's not exactly efficient when you're cutting strips half the thickness of your blade (67% waste). I am just not sure as to why I always end up with the occasional drift cut. Is this something I just need to deal with?

First , the blade may not be parallel to the miter slots. I imagine you use a fence. Check the fence parallelism to the miter slots. Most saws the table can be adjusted for parallel by loosening the table tightening knobs that hold the table to the trunnion. Adjusting the table to the blade lead means you can use the miter slot to reference the fence.
I place a thin metal rule against the blade and hold it there with a small magnet. Then loosen the knobs and tap the table a bit so the rule and the slots are parallel. If you adjust the fence first so it is parallel to the slots then move the fence close to the rule. When the fence looks parallel , lock the table knobs.
If you use a feather board to keep the strips against the fence, the strips should come out the same width each time. 
Alternately, adjusting the fence to the blade lead is what most do. I personally do not care for this method as I get best results with the table adjustments.
Using the feather board and the first method should take care of the problem.
I have cut veneers as thin as 3/64 " and 7-1/2" high with a 3 tpi blade with very little problems. 
mike

[jteneyck]

In addition to Mike's excellent advise, I've sometimes noticed a tendency for the blade on my 14" Delta to want to drift on one cut but not others in the same piece of wood, just as you described.  But I don't ever recall this happening with my much larger Grizzly saw.  I think the key difference between the two, besides shear size, is in the blade tension.  The Delta can only much about 12K psi on a 1/2" blade while I run 27K psi on a 1" blade on the Grizzly.  At lower tension the blade is easily deflected when it hits irregular grain and that just won't happen as easily at higher tension.  


If you have a saw capable of running more tension then try getting it up to around 25 K psi.  But if you are using a 14" cast iron saw don't attempt that as it is not capable of that much tension on a 1/2" blade and something might break or bend in the process.  The best you can do in that case is to make sure your blade is sharp and with equal set on both sides, and to use a slow, steady feed rate.  

John

[FS7]

I have a Grizzly G0555, so basically a starter bandsaw. I know I can replace the tension spring, but that's not a common upgrade. The blade is fairly new and still pretty sharp, though I can try replacing the blade. The guide bearings are adjusted properly, the fence is parallel to the miter slot, and I *think* the blade is parallel. I will check this, and I may also replace the guide bearings with graphite blocks (I've read this is a good upgrade).

From what I can tell, the entire guide post assembly can deflect a bit, and I don't see any way to avoid this. It's a smaller saw with a riser block, and you can't make everything super rigid within the limitations of this tool. On a dedicated resaw tool, I can see a much heavier, stiffer setup with a wider blade working a lot better. Then again, if you can easily resaw wide boards into thin strips, then it's a matter of technique and alignment. I would tend to think that a misaligned bandsaw would frequently or always drift, but for me it's only occasionally.

In mahogany (African, at least), which is not that hard or heavy, I do not really have a problem. Bubinga, very much so. Maple, hit or miss. It does seem like there is some correlation with the hardness of the wood, and it might just be that a smaller saw cannot reliably produce perfect cuts like this. Then again, I know people seem to do this, so it's just me (and a lot of other bandsaw owners).

[Alan S]

If the thin strips are only 1 1/8" wide, cut speed should not be a problem, but could be with wider cuts. Blade sharpness is extremely important to resaw quality. It has seemed to me as important as all the other things (alignment, tracking, tension, ...) put together. A blade no longer sharp enough for resawing can still make other cuts well, and can be demoted to ordinary ripping.

But for strips that narrow, you can just get a cheap 7 1/4" circular saw blade with a 1/16" kerf, and cut them on the tablesaw. Unless you have a Sawstop.

[FS7]

If the thin strips are only 1 1/8" wide, cut speed should not be a problem, but could be with wider cuts.  Blade sharpness is extremely important to resaw quality.  It has seemed to me as important as all the other things (alignment, tracking, tension, ...) put together.  A blade no longer sharp enough for resawing can still make other cuts well, and can be demoted to ordinary ripping.  

But for strips that narrow, you can just get a cheap 7 1/4" circular saw blade with a 1/16" kerf, and cut them on the tablesaw.  Unless you have a Sawstop.

I will try this. I have at least one extra circular saw blade that has a 1/16" kerf so I may try that. The bandsaw blades are about 1/40", so 1/16" is two and a half times thicker, but accounting for loss it may work out close enough. I don't like turning more wood to dust than necessary but for resawing like this it may be worthwhile.

[FS7]

If the thin strips are only 1 1/8" wide, cut speed should not be a problem, but could be with wider cuts.  Blade sharpness is extremely important to resaw quality.  It has seemed to me as important as all the other things (alignment, tracking, tension, ...) put together.  A blade no longer sharp enough for resawing can still make other cuts well, and can be demoted to ordinary ripping.  

But for strips that narrow, you can just get a cheap 7 1/4" circular saw blade with a 1/16" kerf, and cut them on the tablesaw.  Unless you have a Sawstop.

I had a spare Diablo blade (might be $15) waiting for the circular saw, so I put that on. I made a spare zero-clearance insert for it since I had a blank laying around. The total kerf width is about 1/16" but I'm sure I can find thinner.

I am very impressed. I cut a few 1/8" strips of purpleheart, which isn't the easiest to cut, and there were effectively zero saw marks or burns on it. That's more than I can say for my regular blades, even the ripping blades. Compared to the struggles I faced on the bandsaw, this is totally worth it. I think I may actually keep this as the dedicated blade. It looks like it can manage about a 2" depth of cut, which is more than I need for almost any job.

[kurt18947]

Home Depot has a fair selection of Diablo 7 1/4" blades. I use them on a cabinet saw for cutting small pieces. They seem less "grabby" than 10" 40 tpi saw blades in addition to the thinner kerf.

[daddo]

Try slowing your feed rate.
Sometimes combined with a blade that's sharper on one side than the other will cause this.

[Stwood_]

About the only time I resaw with the bandsaw is when the tablesaw won't do it.

I'd say a lot of resaw problems (if the machine is correct) have to do with the sharpness of the blade's teeth from one side to the other, or the set is different.