How much drift adjustment does a bandsaw fence need?

[eyekode]

I am drawing up a bandsaw fence and trying to figure out how much drift adjustment I really need. I have heard that drift can be adjusted out and I have been able to minimize mine. But I still want to build some drift adjustment into my fence.

How many degrees do you think you need? I am currently designing for 5 degrees either way. That seems like plenty. Actually 1" over a 16" length seems about all you would need (1.5 degrees). Any opinions?
Thanks!
Salem

 

[bobby g]

Salem,

5 degrees should be plenty based on what I see in my shop.

Bob

 

[Travis Porter]

I agree, 5 degrees should be plenty.

 

[eyekode]

Thanks guys. 5 degrees it is. I will post some pictures when done .

 

[boxxmaker]

One of the biggest problems with resawing is the BS.If it is not tuned correctly,plus have a GOOD blade on it,it can run all over the place.So make sure it is properly tuned with a good blade or the fence will be about worthless.

 

[Bill Clemmons]

Salem. I agree with the others, 5* should be enough. But every blade is unique and has it's own drift. The 5/8" blade I'm using right now drifts 2* to the right. When you say 5*, I assume you're allowing for right and left of center?

Rather than check each blade when I put it on, I write down the drift on a small tag and then attach it to the blade when I take it off and store it. That way I know where to set the fence when I put that blade back on.

Bill

 

[eyekode]

Salem. I agree with the others, 5* should be enough. But every blade is unique and has it's own drift. The 5/8" blade I'm using right now drifts 2* to the right. When you say 5*, I assume you're allowing for right and left of center?

Rather than check each blade when I put it on, I write down the drift on a small tag and then attach it to the blade when I take it off and store it. That way I know where to set the fence when I put that blade back on.

Bill

Bill, Yes I mean 5* to the left and 5* to the right. So a total of 10*. How do you record the drift of a blade? Some type of protractor against the fence? Or offset of the fence relative to the edge of the table from front to back? And I guess if the tracking changes at all the drift will change as well?

Thanks!
Salem

 

[Mtnman]

I agree that every bandsaw blade seems to have it's own degree of drift, but dosen't the grain in the wood you are cutting also have a large effect on drift? I use a featherboard when ripsawing to help reduce drift.

 

[boxxmaker]

Yes the grain orientation and hardness of the wood can make a huge differance.That is where a top quality ( and very sharp) blade comes in.I just use a flat fence with a half round dowl rod glued to it about half way down.I draw a line down the board and just follow the line and if your saw is tuned up as mentioned then you should get good results,but if not,then you may end up with a perfect cut where you draw the line,but the bottom of the blade can be so far off,it can come out the side of the board.like already said,no matter what kind of fence you have,the saw makes the differance.I resaw a lot of well sesoned birdseye maple and with out a GOOD blade it don't cut so good

 

[Bill Clemmons]

Bill, Yes I mean 5* to the left and 5* to the right. So a total of 10*. How do you record the drift of a blade? Some type of protractor against the fence? Or offset of the fence relative to the edge of the table from front to back? And I guess if the tracking changes at all the drift will change as well?

Thanks!
Salem

As several others have pointed out, the first step is to make sure your BS is properly tuned, you're using a good quality blade (usually not the one that came with your BS), and you have the blade properly tensioned. With that done, now you can track the drift for that particular blade.

Start with a fairly long, narrow piece of wood, say 10-15" long by 2-4" wide. If you cut primarily hardwoods, then use a piece of scrap hardwood for this test. Make sure at least one long side of the board is perfectly straight. Now mark a line down the center of the board lengthwise, exactly parallel to the straight edge. Without using the fence, begin cutting down the line freehand, making sure you keep the blade right on the line. Stop the cut about half way down the board; hold it, or clamp it, exactly where you stopped cutting; turn off the saw. Now put a protractor along the straight edge of the board and the infeed side of your table. The board is probably going through the blade slightly skewed. The amount of that skew is the "drift" of the blade. Usually it's only a few degrees. If it's more than the 5* you're allowing for, then you might need to re-tune your saw or get a better blade. I usually find mine in the 1-3* range, and that's with run-of-the-mill blades. Once you know the amount of drift, you can adjust your fence for it.

As someone else pointed out, they use a vertical dowel attached to the fence and guide the work through freehand when resawing. For resawing thicker pieces, this is actually the recommended way to do it. Using a fence for resawing is usually only recommended when cutting thin pieces, like veneer.

I hope this helps. If my description doesn't make sense let me know and I'll try to scan an article in one of the ww magazines and send it to you.

Bill