Bandsaw Blade Drift Not A Fence Problem

[Julie Moriarty]

Fine Woodworking Magazine is standing by its earlier statement that blade drift on your bandsaw is not something that should be fixed at the fence. They have a new video out showing proper blade choice, a sharp blade and a properly set blade will eliminate drift. There goes the Driftmaster's advantage!

http://www.finewoodworking.com/tool-guide/video/how-to-change-a-bandsaw-blade.aspx

For years I always set my bandsaw fence parallel to the guide slot. Initially, that worked fine. No drift. But as the blade dulled, drift started becoming a problem. Thing is, I didn't think the blade could have dulled so quickly so I blamed drift on the wood, the fence setting, the tension and everything else. Then I bought a Lennox Woodmaster carbide tipped 1.3TPI blade and drift became a problem of the past. So did the quick dulling I was seeing with the Wood Slicer blades. However, a good fence is imperative. If your fence moves, you can't expect the cut to remain a consistent thickness.

I'm glad to see FWW working on dispelling the myth about blade drift.

[Peter Kuhlman]

Michael Fortune's pet peeve is the whole "drift" idea. He has shown many times how to set up a bandsaw so that "drift" can be overcome with proper alignment and tension. Attended a class of his and he recommends basic low cost saw blades as well as the life goes up again with proper alignment.

[Myk Rian]

Not all saws play well with a carbide blade. 14" in particular. Wheels are too small, blades break.
If I start getting drift, time for a new blade.

[Jim Neeley]

Not all saws play well with a carbide blade. 14" in particular. Wheels are too small, blades break.
If I start getting drift, time for a new blade.

Jeeze, Myk, really? If I start to get drift I just fire up the outboard!! <Sorry, old fishing reference>

[john lawson]

FWW got silly on this one. They are saying, in effect, if you have any drift then you need to change saw blade. That might be fine for a commercial shop or someone who has unlimited finances but it's not the situation for most woodworkers.

I do use carbide blades, and if I notice some drift I do not throw away the blade and put a new one on. At least not until the blade makes a difference in the cut. Then I will change it.

Every once in a while FWW gets really squirrely and comes up with something off the wall like this. Fortune should have defined the problem a little better and then explained how to overcome drift, then explain about dull blades and changing the blade.

Silly. my $.02

[David Kumm]

When it comes to machinery FWW is always silly. Dave

[ian maybury]

:) What's for sure is that there's a lot of conflicting information out there. It IS possible to chase drift around the place when it occurs by re-aligning the fence, and i've done it - but it's probably not getting to the first cause of the problem, and may not (didn't for me anyway) deliver a consistent result. (it can't unless the cause of the drift remains stable)

My playing around over the past few years seems to confirm the suggestion that presuming a correctly sharpened and jointed blade that can/has cut straight that the onset of drift is mostly to do with position of the blade on the tyres (i.e. tracking) - that if a previously straight cutting blade starts to drift that it's probably that the blade has moved on to a different part of the tyre. Which in the case of especially a high cambered tyre and less than 100% control by the guides (almost an inevitability) makes a difference to the alignment of the band relative to the fence. (think it through).

I've a sneaking feeling that sawdust caking on the tyre, or the onset of minor tyre irregularities, or the onset of flexing/twisting in a lighter bandsaw frame under more tension than it can handle (flimsy frames seem to cause a lot of grief and frustration, and may explain why light tension is better on lighter saws - so many of these problems evaporate with e.g. a heavy duty Italian), or the guides fighting the natural tracking of the band on the wheels can all play a part when the situation proves to be unstable too.

It follows from this that you can alter the tracking to suit the fence by tuning the wheel alignment so that the blade tracks on a different part of the tyre. Also that may also suit to use fence alignment to get it tracking straight for a preferred blade on wheel location or guide setting.

The other possibility is that something other than normal wear has happened to make the blade cut differently off one side than the other if a problem suddenly kicks in - but it should keep on tracking OK with normal even wear. (has so far for me anyway) Prime suspect with a new blade on a saw that has previously been OK has to be a misaligned weld, or a badly sharpened blade...

ian

[John Coloccia]

I've a sneaking feeling that sawdust caking on the tyre, or minor tyre irregularities, or flexing/twisting of a lighter bandsaw frame under more tension than it can handle, or the guides fighting the natural tracking of the band on the wheels can all play a part when the situation proves to be unstable.


You really need to watch the tracking and get the blade in a stable location. When the blade isn't sitting properly on a crowned tire, the blade will twist back and forth on really minor imperfection in tire thickness. When you have it just right, the blade will be nice and steady. I'll bet just that one thing is the cause of lots of problems and poor cut quality.

But a dull blade cuts like a dull blade. I LOVE the WoodSlicers. They cut like butter, but they go dull SOO quickly. I'm using a ResawKing now. Doesn't cut like butter but the finish is amazingly good and it lasts a good long time.

[John TenEyck]

And not just about machinery. Lately, they've gone completely over the edge. The one I enjoyed the most was when Steve Latta a couple of issues ago said that you can relieve internal stresses in large parts by dropping them on the floor. Who knew my clumsiness had a real benefit !

John

[Richard Wagner]

All of the blades that I saw during this clip were on the order of 5/8" or 1/2" blades. Are they just talking about resawing blades or do they mean to apply this theory to even narrower blades. I didn't know that you could get narrow blades (1/8" - 1/4") with 3tpi.

[John Coloccia]

And not just about machinery. Lately, they've gone completely over the edge. The one I enjoyed the most was when Steve Latta a couple of issues ago said that you can relieve internal stresses in large parts by dropping them on the floor. Who knew my clumsiness had a real benefit !

John

No, really? The next time I run into him at the local Woodcraft (i.e. the Connecticut Valley School of Woodworking where he occasionally teaches some classes) I'm going to have to needle him about that a bit. LOL.

We all have our little quirks. Fortunately, no one will give me any space in a magazine to expose mine to the world.

[Michael Dunn]

And not just about machinery. Lately, they've gone completely over the edge. The one I enjoyed the most was when Steve Latta a couple of issues ago said that you can relieve internal stresses in large parts by dropping them on the floor. Who knew my clumsiness had a real benefit !

John

Are you serious? That was in FWW?

[paul cottingham]

And not just about machinery. Lately, they've gone completely over the edge. The one I enjoyed the most was when Steve Latta a couple of issues ago said that you can relieve internal stresses in large parts by dropping them on the floor. Who knew my clumsiness had a real benefit !

John
Seriously, I swear that is why I am always dropping wood on the floor. I am preparing it for use. I feel better, I used to think I was just being clumsy.

[Steve Rost]

That video is another example of how they have dumbed down their content to appeal to the masses. Appeal to the masses and you get more subscriptions.

[Erik Loza]

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

[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 (http://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.