Bandsaw: tracking and drift and the snodgrass method

[Adrian Mariano]

I saw this post http://www.craftsy.com/blog/2015/05/resaw-bandsaw/ wherein the author suggests that bandsaw drift is caused by the blade not being centered on the wheel when you have a crowned wheel. He says you can fix drift by tweaking the tracking. But then I found an article and video where Snodgrass says to align the bottom of the gullets with the center of the wheel.

On my saw (PM1500) I have the blade tracking in the center of the top wheel. Blade is a 3/8" carbide tooth Trimaster. It tracked like this out of the box. But drift is about 1/2" and it's hard to turn the table enough to adjust for it. (I want to keep the fence parallel to the mitre gauge.) So I'm interested in a blade adjustment that would enable me to reduce or eliminate drift. But it seems like there's no consensus about this approach.

Many people, including the author of the post above, suggest that centering the blade on the top wheel will eliminate drift. But my blade is centered and I still have drift. In reading past discussions is seems like lots of people are skeptical of the Snodgrass approach, and of course manufacturers aren't recommending this approach.

Does anybody have any advice on how to reduce drift by adjusting the saw?

[Myk Rian]

In reading past discussions is seems like lots of people are skeptical of the Snodgrass approach,

People like me.
I center the blade on the top wheel and "flutter" tension.
You just might have a bad blade.

[Phil Thien]

Adjust the tracking of the blade on the top wheel, until you eliminate the problem.

[Rod Sheridan]

If the blade is damaged or dull it will not track properly when cutting.

The miter slot in the table has to be parallel to the blade path, that only has to be adjusted once.

Now adjust your rip fence so it's parallel to the miter slot. This is a once only adjustment.

Now you adjust the tracking so the blade is centered on the top wheel. Make a test cut with the rip fence, check that the blade is centered in the kerf, parallel to the direction of travel. If not make a miniscule tracking adjustment to correct that and recheck with another test cut.

Regards, Rod.

[Jeffrey Martel]

I use the Snodgrass approach quite successfully on my 14" grizzly saw. Can't say about the other one since the Snodgrass works for me. As was said, your blade may be dull.

[Art Mann]

Myk could very well be right about a bad blade. In that case, no amount of adjustment will make it right. On the other hand, I have always been able to adjust the tracking of my band saws as Phil suggests so that the blade cuts parallel to the miter slot and no fence compensation is necessary. I have done this successfully so many times that Mr. Snodgrass sounds downright silly to me on this point. I think drift angle is normally adjusted out by varying the angle of the rip fence because it is the easiest, but not necessarily the best, way to do it.

[Bob Wingard]

I've used Alex's method for several years now ... has worked great on my old DELTA 14"

[glenn bradley]

Adjust the tracking of the blade on the top wheel, until you eliminate the problem.

+1 on this.

Blade Track 3.JPGBlade Track 1.JPGBlade Track 2.JPG

Exaggerated for clarity the same can apply for non-crowned tires if the tooth set is enough to foul the travel path. I set my saw to saw straight and change blades with impunity. Its a tool, it should do the work .

[David Ragan]

No doubt all the above factors enter into the equation-"But"

I get the very best results with the resulting surfaces when adjust the angle/parallelism of my fence slightly.

I do this by taking a piece of scrap, setting everything up just as it is about to be used, mainly the tension and height of blade guard.

Take a piece of scrap that is a least a inch thick, saw 4-6" into it.

Stop the saw. Leave the blade in the piece of wood; don't touch anything.

go round to the back side with the light just right, and see if the blade is actually exactly parallel in the kerf of the cut.

Adjust the fence-probably 1-4mm.

Saw another kerf.

This method has afforded me great results. It is a little tedious, but worth it.

[Jim Matthews]

If not make a miniscule tracking adjustment to correct that and recheck with another test cut.

Regards, Rod.

+1 on this. The method shown in the video gets VERY close. It's an alignment of many factors, some tweaking is to be expected.

[Roger Pozzi]

I use the Snodgrass approach quite successfully on my 14" grizzly saw. Can't say about the other one since the Snodgrass works for me. As was said, your blade may be dull.

Plus 1 !!!
I found the Snodgrass video while still shopping for my bandsaw. When I was setting up my saw straight out of the box, I followed his instructions to the letter. I even went as far as marking the center of the top wheel since the only way to look at it was from an angle. It works for me and I've never looked back at the time I spent setting it up.
My thought is, Alex Snodgrass makes a living with bandsaws so, why not give him a little trust.

[Adrian Mariano]

+1 on this.

Blade Track 3.JPGBlade Track 1.JPGBlade Track 2.JPG

Exaggerated for clarity the same can apply for non-crowned tires if the tooth set is enough to foul the travel path. I set my saw to saw straight and change blades with impunity. Its a tool, it should do the work .

Seems plausible to me. But unfortunately doesn't seem to match the reality of how my saw cuts. Blade is centered but I have 1/2" of drift.

[Adrian Mariano]

If the blade is damaged or dull it will not track properly when cutting.

The miter slot in the table has to be parallel to the blade path, that only has to be adjusted once.

Now adjust your rip fence so it's parallel to the miter slot. This is a once only adjustment.

Now you adjust the tracking so the blade is centered on the top wheel. Make a test cut with the rip fence, check that the blade is centered in the kerf, parallel to the direction of travel. If not make a miniscule tracking adjustment to correct that and recheck with another test cut.

Regards, Rod.

My blade is a new carbide tipped 3/8" blade. It cuts well. It's not dull.

What do you mean about adjusting the miter slot parallel to the "blade path"? I have attempted to adjust the miter slot to be parallel to the cut line. This is a tricky adjustment. I did recently have the inspiration to use my laser line level to make this easier. I lay down a line parallel to the cut path and it gives me something to reference as I turn the table. However, I had trouble turning my table 1/2". I just realized I may have made an adjustment I shouldn't have, that fowled up something else. And after all this, the blade is off center in the insert, which is kind of weird. So I'm looking for another way.

Do you think checking the blade position in the kerf is more reliable than making a long freehand test cut along a line and observing the angle of the workpiece? It seems like the blade-in-the-kerf method would be easier with larger blades, but when I tried it with my 3/8" blade I didn't feel like it was very clear. So I went back to the other approach of cutting a 2' workpiece half way along a marked line freehand.

I had been imagining that the necessary adjustment was big. (Certainly the Snodgrass adjustment is big!) Are you saying that I should be able to eliminate the 1/2" of drift by making tiny adjustments? Is there a system to this? Like if the cut line is veering to the left which direction would I adjust the tracking?

[Bill Huber]

My blade is a new carbide tipped 3/8" blade. It cuts well. It's not dull.

What do you mean about adjusting the miter slot parallel to the "blade path"? I have attempted to adjust the miter slot to be parallel to the cut line. This is a tricky adjustment. I did recently have the inspiration to use my laser line level to make this easier. I lay down a line parallel to the cut path and it gives me something to reference as I turn the table. However, I had trouble turning my table 1/2". I just realized I may have made an adjustment I shouldn't have, that fowled up something else. And after all this, the blade is off center in the insert, which is kind of weird. So I'm looking for another way.

Do you think checking the blade position in the kerf is more reliable than making a long freehand test cut along a line and observing the angle of the workpiece? It seems like the blade-in-the-kerf method would be easier with larger blades, but when I tried it with my 3/8" blade I didn't feel like it was very clear. So I went back to the other approach of cutting a 2' workpiece half way along a marked line freehand.

I had been imagining that the necessary adjustment was big. (Certainly the Snodgrass adjustment is big!) Are you saying that I should be able to eliminate the 1/2" of drift by making tiny adjustments? Is there a system to this? Like if the cut line is veering to the left which direction would I adjust the tracking?

If your cut is tracking to the left or to the back of the saw then you would want to adjust the tracking on the top wheel to the back a very small amount and do a test cut.
With that said I would say if you have the blade centered on the upper wheel and it is tracking off 1/2" I would look at a different blade. I have a Jet 14" and at one time I got a cheap blade, (1/2") and it would not track at all I worked with it but could not get it tracking straight. I then got a blade for Timber Wolf installed it, set the tracking and it was straight as a string.

[Rod Sheridan]

Hi Adrian, the miter gauge slot should be parallel to the blade path.

Adjust your blade so it tracks properly on the upper wheel then make sure your miter slot is parallel. The table shouldn't need or be able to be adjusted much to do this.

Normally, tracking adjustments are miniscule, and I don't normally adjust it when changing blades.

I suggest you buy a good quality non carbide blade, and set up your saw.

If you're using a very small blade then you just look at the drift of the cut, drifting into the fence, blade too far forward. Drifting away from the fence, blade too far rearward.

As I said you don't normally adjust tracking once the saw is set up............Rod.