Band Saw Fence and Drift

[fritz eng]

Is band saw drift a factor when using a fence? Obviously the use of a fence is primarily for parallel cuts and re-sawing.

[Rob Luter]

I've seen it suggested that drift is really misalignment between your fence and blade. I spent a ton of time aligning my band saw table and fence when I got my saw. I don't have much of an issue with drift.

[Doug Garson]

Yes, if your blade has drift and your fence is not set at the drift angle then the cut will try to follow the drift angle and push the workpiece towards or away from the fence. If the workpiece stays in contact with the fence, the blade may deflect (depending on how close your guides are) or just bind in the cut.

[Thomas McCurnin]

I think the absolute best way to avoid drift with a fence is to tune up your band saw, although you can measure the drift and create an angle compensator, which is old school. The best method I have seen is on a video called tuning up your band saw for the anally retentive. https://www.youtube.com/watch?v=9DzbJYIPPNE

[fritz eng]

A follow-up question: do blades of different widths drift differently? Additionally, once the drift of a blade is determined and the table adjusted accordingly, will that be the "permanent" position of the table for all blades? In other words will the table set up be a one time event? Thanks

[Zachary Hoyt]

A sharp blade on a well set up bandsaw will not drift if the feed rate is kept reasonable. Each blade will be dull in its own way, so if the blade is the problem then when you change blades the drift will change. If you switch blade widths or types then I would also expect the drift to change and require readjustment. I have not learned to sharpen blades yet, so for me when a blade begins to drift it is time for a new one, which has always taken care of the problem so far.

[Doug Garson]

My understanding is there are two potential causes for drift, either the saw setup, meaning the blade is not parallel to the miter slot, or the blade. If you cut curves with the blade, one side of the blade may dull more than the other causing drift or the blade itself as manufactured may not have equal set or sharpness on both sides. So you can start with a well set up saw with no drift and after cutting a bunch of curves or changing blades start getting drift. Best to check for drift before you make any critical rips or resaws if you have been cutting curves or change blades.
Sharpening blades is not difficult assuming not carbide blades or high tpi blades. I just tried it for the first time a few days ago and took about 10 minutes to sharpen a 105" 3 tpi blade. Lot's of videos out there showing how, I did it on the saw(unplugged) and just touched the tip with the side of a cut off blade in my Dremel. Dramatically improved the cut, haven't checked if it affected the drift yet, will do that if I need to rip or resaw with the fence.

[Rod Sheridan]

A follow-up question: do blades of different widths drift differently? Additionally, once the drift of a blade is determined and the table adjusted accordingly, will that be the "permanent" position of the table for all blades? In other words will the table set up be a one time event? Thanks

Yes.....Regards, Rod

[Derek Cohen]

Drift can also occur when the wood is reactive, opens up when sawn, and one side pushes away from the fence.

Regards from Perth

Derek

[Robert Hazelwood]

Drift can also occur when the wood is reactive, opens up when sawn, and one side pushes away from the fence.

Regards from Perth

Derek

Yes, I suspect a lot of reported drift is actually cause by this. It is not always obvious what is happening and what you notice is the blade drifting towards the edge/face you had against the fence.

Otherwise I think it is an issue with blade set or sharpness. This is what would cause a handsaw to go off a line.

I see how the setting of the wheels and tracking can affect the angle of the blade, but the blade should still cut straight at whatever angle it happens to be. So it is just a a matter of adjusting the wheels until the blade is parallel to the miter slot and fence, or adjusting the table to suit the blade.

I can't see any reason why a blade would cut at say 5 degrees off from the angle of the band, without there being something wrong with the blade.

The other issue might be the band flexing under the feed force. I can see this causing the blade to want to twist and wander. This may be why drift seems to be a less reported problem on larger heavier saws running bigger bands at higher tension. The greater beam strength minimizes blade flex.

[Darcy Warner]

The other issue might be the band flexing under the feed force. I can see this causing the blade to want to twist and wander. This may be why drift seems to be a less reported problem on larger heavier saws running bigger bands at higher tension. The greater beam strength minimizes blade flex.

As a connoisseur of large bandsaws, there is a difference in performance with different tensioning mechanisms, wheel styles, weight, etc.

Knife edge style tensioning makes a noticable difference in smoothness. Solid disc or Carter/tannewitz wheels are much improved vs. cast spoked wheels, never had a BS with a miter slot.

If I need to resaw on my BS, i have a single point fence i use.

I prefer to resaw with a resaw.

Blades will drift, it's mostly due to tooth set when new and tooth wear when used.

[Christopher Charles]

The fence on my saw is straightforward to adjust for changing drift, which I usually check when switching blades using a ~24" piece of scrap. Mark a line parallel to the fence side of the scrap, carefully freehand cut the scrap about 1/2 through, hold in place to the table. Nearly always it will be non-parallel to the table by a degree or two. Adjust the fence parallel to the scrap and that's it.

[Josko Catipovic]

I remember once setting up my bandsaw for drift, and then rounding the back of the blade with a stone. I happened to just touch the stone to the teeth on one side (oops!) and on the next cut, drift angle was way different. That involuntarily confirmed that teeth set is an important part of drift. (I am NOT suggesting that one adjust drift by stoning one side of the teeth.)

[Robert Engel]

Ok, this always gets me going.......:-D

First of all, its a fallacy to think drift means there is something wrong. Common sense tells me it that were true, bandsaw fences wouldn't be made to adjust and the manual for every single bandsaw I've ever owned (4 to date) talk about adjusting the fence for drift.

You can do the tricks everybody talks about to eliminate it, then find out for yourself it works or doesn't work. It certainly doesn't work on either one of my bandsaws.

I like Michael Fortune's technique of setting fence parallel to slot and adjusting table.

That said, how hard is it to simply align fence to drift?

I know I'm checking that every time I resaw regardless of how well tuned my saw is.

[fritz eng]

I'm beginning to think that regardless of drift, one will do their best to have the material tight up against the fence to get the desired cut and let the "chips fall where they may"...............