Bandsaw Blade Drift Not A Fence Problem

[Chris Parks]

This subject has been around before and showed that tracking is the culprit. There is a video somewhere at a wood show done by someone from Carter who demonstrates why ot happens and how to fix it. It stands to reason that if a wheel is crowned changing the position of the band on the wheel will change to angle of the band and if the tracking is wrong drift is the result.

[ian maybury]

This is a bit of a hijack Erik, but a question relating to Italian saws with flatter/less cambered wheels.

There comes point where narrower blades start to become inclined to wander on wheels like this. Any smart moves for gaining some extra stability/permitting the use of narrower blades?

I've seen the slot in a block of phenolic guide method (looks very useful), but there are presumably limits to what it can achieve....

ian

[Grant Wilkinson]

This is the video that Chris mentionned

http://www.youtube.com/watch?v=wGbZqWac0jU

[Jerry Thompson]

Here is the best bandsaw video I have seen. It works and I can now re-saw among other things with no pucker factor.

www.youtube.com/watch%3Fv%3DwGbZqWac0jU

[John Coloccia]

Great video. I'm sure we all do things a little differently, but Alex pretty much nails it, for crowned tires at any rate. It's really that simple.

[Erik Loza]

This is a bit of a hijack Erik, but a question relating to Italian saws with flatter/less cambered wheels.

There comes point where narrower blades start to become inclined to wander on wheels like this. Any smart moves for gaining some extra stability/permitting the use of narrower blades?

I've seen the slot in a block of phenolic guide method (looks very useful), but there are presumably limits to what it can achieve....

ian

Ian, what I have found is that on the "tall resaw" machines, you reach a point of diminishing returns very quickly because the threshhold between "prefect tension" and "blade snaps" on, say, a 1/4" blade that is 150"+ long is very slim. Yes, smaller guides can help with this but the real answer is, if you see yourself doing lots of work with a 1/4" or smaller blade, then you need a smaller BS that is dedicated specifically for this, not the big Italian machine. That's not what it was designed to do.

Just my thoughts,

Erik Loza
Minimax USA

[David Kumm]

Erik, as usual, brings up a good point that has been lost as the resaw heights have increased. There is a tradeoff in how smooth a saw cuts as the wheels get farther apart. The best saw for the job is the one with the least resaw height needed. Small blades do best when kept under 12" resaw. The older 16-18" Italian saws were perfect for small blades even sold- incorrectly IMO- as resaw machines. The new ones are better resaw but worse small blade saws. Dave

[ian maybury]

Thank Erik - hope springs eternal but that makes sense. In this case the hope was just that maybe that there might be a narrow blade strategy that isn't widely known.

There's a kind of a grey area on my Agazzani (and probably also on other similar saws) where once below say a 1/2in blade when the tracking starts to get a bit indeterminate, but is still fairly usable. More tension helps, but so far i've been fairly conservative. Even a small difference can help a lot in that zone....

ian

[David Kumm]

Thank Erik - hope springs eternal but that makes sense. In this case the hope was just that maybe that there might be a narrow blade strategy that isn't widely known.

There's a kind of a grey area on my Agazzani (and probably also on other similar saws) where once below say a 1/2in blade when the tracking starts to get a bit indeterminate, but is still fairly usable. More tension helps, but so far i've been fairly conservative. Even a small difference can help a lot in that zone....

ian

For what is worth, Ian- and that may not be much-, I run my 1/4" bimetal blades at 30,000+. At that tension the blades don't have any problems, even resawing up to 6". Don't know how long they last because I haven't broken one yet. Dave

[John TenEyck]

Here is the best bandsaw video I have seen. It works and I can now re-saw among other things with no pucker factor.

www.youtube.com/watch%3Fv%3DwGbZqWac0jU

Is this the video where he says not to fool around with machine alignment, that the manufacturers certainly know more about it than you do so just leave it alone? Horse puckies ! If the wheels aren't close to being planer no amount of tracking or tension will make the saw cut straight. After I got mine aligned properly tracking was a piece of cake; prior to that, nothing worked. After I got them aligned the most important thing to cutting straight was, in order, tracking and a uniformly sharpened blade. Blade tension has a lot less to do with it on my saw - Delta 14" with riser. That's a good thing, because you can't get close to the tension recommended by most blade manufacturers anyway. 12,000 is about the practical limit with a 1/2" blade.

John

[ian maybury]

Ta David, i've not tried a narrow carbide (which probably has a high strength steel band) - only an M42 and being cautious didn't try pushing the limits on that on tension which may be why i saw some variability.

I guess as ever in this stuff John it's all a matter of the starting assumptions. There's got to be more than a few saws about whether ex factory or as a result of 'adjustment' where the wheels are out and need aligning. Not to mention that a high camber wheel will probably tolerate a lot more misalignment than the flatter variety, but at a price in other situations...

ian

[John McClanahan]

No more than 3 TPI? Really? If you like Timberwolf blades, you will have to use 3/8" or wider. No 3 TPI in 1/4" blades.

John

[Jim Stewart]

Spot on Erik!

[Jim Matthews]

In my experience, blade "drift" is always a function of either improper blade tension and/or tracking. Nothing to do with the fence. If the saw in use can't do either of those two things properly with th blade you want to use, that's a different conversation.

Just my 2-cents.

Erik Loza
Minimax USA

Pretty much what Asa said in the vid-ya.

Michael Fortune's article (many moons ago) covered the same ground.
It's worth mentioning, as there are always new woodworkers coming into the mix.

I followed this basic advice (getting the right size blade, running it in the center of the wheel and getting just enough tension dialed in) with my MM20 which now cuts beautifully,
with a basic steel blade - just like Asa said, and Michael before him.