Why angle fence for drift rather than centering bandsaw blade?

[Mike Leung]

I read posts on tuning bandsaws and some people recommend adjusting the fence for drift. Why don't people just adjust the band on the wheel until it is running straight? A table saw blade should also be tuned so the blade runs parallel to the miter slots. Why wouldn't you do the same for the bandsaw?

[Jason Beam]

I read posts on tuning bandsaws and some people recommend adjusting the fence for drift. Why don't people just adjust the band on the wheel until it is running straight? A table saw blade should also be tuned so the blade runs parallel to the miter slots. Why wouldn't you do the same for the bandsaw?

Good question. Some people don't get it

If you have flat wheels, it's much harder to do. But if you have crowned wheels, it's easier to dial out any drift and your fence can stay put. Just takes a little patience.

[Jerry Thompson]

Early on I was instructed how to set my fence to be inline with the drift. I watched Alex Snodgrass' video on You Tube and set my BS up as he demonstrated. It was a game changer for me concerning re-sawing.

[Dennis McDonaugh]

My MM16 doesn't seem to ever have much drift in the cut, but I've never been able to change it moving the blade on the wheel.

[Sam Stephens]

+1. makes cuts so much simpler.

Early on I was instructed how to set my fence to be inline with the drift. I watched Alex Snodgrass' video on You Tube and set my BS up as he demonstrated. It was a game changer for me concerning re-sawing.

[Frederick Skelly]

Thats kind of strange. My experience was just the opposite of Jerrys. I used to adjust the fence. Then I read somebody or others book that said adjust the band on the wheel. That was a big game changer for me.

Wonder what Mr Duginske would say.

[Chris Parks]

I never read anything and just centred the blade and had no drift. I could never understand what others were on about and why they had this huge problem until I saw AS's video and then it all became clear. Dennis, your MM16 has flat wheels, any BS with cambered wheels can use the centred method but flat wheels obviously can't. It is the camber that influences the tracking by changing the angle of the blade.

[Art Mann]

My band saw tires have a little crown in them. I use this property to move the blade tracking until there is no drift. It can be tedious but you don't have to do it often unless you change blades a lot. I have several descriptions of how to adjust the fence to match the off angle cut but that just never seemed like the right way to fix the problem.

[Chris Parks]

I think that the tracking adjustment's primary function has become lost over time for some reason or maybe just misunderstood from the outset. I am sure the cambered wheel plus the tracking adjustment must always have been meant to do just what AS advocates. Has anyone else got a view on this?

[Rob Price]

I'm luky enough to know Alex, he comes to our local WW'ing club meetings about once a year and reviews the bandsaw setup each time. I did read the bandsaw book that talks about coplanar wheels and setting fence for drift, etc. Then I saw Alex put on a demo. Manufacturer's have put a lot of time into the crown on the wheels and the angle/thrust of the wheels. Leave them alone (with regards to being coplanar). I follow his instructions and I've never had drift. I set my fence up parallel to the blade, put the gullet of the teeth on the middle of the top wheel, setup my bearings, and away I go. I've cut some thin veneers out of various woods and never had an issue. Often the blade never even engages the side bearings.

I also just use the tension scale on the saw and don't worry about it.

[Alan Schaffter]

A well aligned saw may still drift. Drift is also often caused by the blade when the teeth are offset more to one side or another.

[John Downey]

I've known saws that drift in spite of having the blade centered on the top wheel. That is where the discussion always turns to whether the wheels are co-planar (or more usefully, whether the fence/table edge is parallel to the top wheel axis).

I agree though, that one should not mess with the wheels, it is a waste of time. If there is drift with the blade centered on the crown, just adjust the fence to match and get to work cutting stuff!

If it really vexes the owner, look for an older saw that was built well. I think that is most of the question here, how much effort the manufacturer was willing to put in to making it track nicely.

There is nothing "wrong" about a saw that drifts some, now that fences have caught up a bit and adjustable ones are available. Bandsaws just cut parallel to the top wheel axis of rotation (assuming proper tooth set and that the blade is centered on that wheel's crown).

[John TenEyck]

I am squarely in the camp that believes the blade should track straight so that the fence can be aligned with the miter slots. It could be that the saw manufacturers design their BS's so that the blade will track straight, but that is no guarantee that each and every saw leaving the factory was set up correctly, or prevents it from getting "readjusted" during shipment, or during use. With all due respect to AS, he is making a big assumption that the saw arrived as the manufacturer designed it when he says not to bother checking/adjusting the wheels. He further assumes no saw ever wears or deviates from factory specs as it ages.

It was only after I checked whether or not the wheels on my BS were coplaner, and found they weren't even close, that I was able to resolve the tracking problems I had with it. Once I adjusted the wheels so that they were coplaner, the blade tracked beautifully in the center of the wheels and was square in two both axes to the table. However, the saw still would not cut straight, and this is where the comment above about the influence of the blade came into play. Turns out the blade was not equally sharp on both sides, even though it was brand new. With a new blade with equal set and sharpness on both sides, the saw now cuts beautifully straight.

It may be possible to get a saw to cut well even if it doesn't cut straight, but that can't be what any manufacturer would want, nor do I. It only took a couple of hours to "fix" my saw - and it's now a joy to use, something I would never have said before.

John

[glenn bradley]

I have had 4 different bandsaws and have adjusted saws for others. I have never accepted drift and always just adjust the saw to cut parallel to the miter slot (when present) and set the fence to the slot as well. I change blades with impunity . As a disclaimer and a testament to my limits; I have not run carbide tipped blades and I use the flutter method to set tension. Some Ellis blades I tried (didn't care for them) required a bit more tension than say a Timberwolf or a Woodslicer but, they still tracked true. I was very confused when I saw that they sell an expensive fence solely to deal with drift. Later I realized there is a market for it and many folks sing its praises. I just adjust the saw. YMMV.

[Mike Leung]

I have have an Inca 10" and a Laguna 14". Both saws have wheels with slight crowns. My fences have been shimmed to 90. This is what I do to setup my saws. Everytime I change to a new blade I need to adjust the camber on the top wheel. I check the table's tilt and adjust for 90 if needed. I use a precision square on the back edge of the blade and adjust until I get no gaps so my blade is 90 degrees to the table. I then mark a piece of S4S wood and make cuts against my fence, measure with caliper and dial in the camber and table tilt. I check with my miter gage to see how close I am as well. If the cut is drifting to the right I dial the band towards the back of the wheel and if if drifts left to the front.
It takes me 30 minutes or so to do this procedure so it is a huge pain in the ass. That was the reason I bought my Inca so I don't have to change blades on the Laguna. I cut and fine tune tenons for through mortises on my bandsaw so I need to cut straight both side to side and top to bottom. If I don't align my blade properly, I cannot cut my tenons precisely on the bandsaw and will use my tablesaw instead.

The teeth being offset more on one side could cause problems. I use a Laguna resaw kings and woodslicers and have not had any offset problems. So could it be that some people have blades that do not have even offsets so they can not align their them properly? I am always open to better setup techniques. Mine just takes a bit too long and I dread it everytime.

A well aligned saw may still drift. Drift is also often caused by the blade when the teeth are offset more to one side or another.