Replies

1. 
   johnhardy | Feb 18, 2003 08:36pm | #1

   Blade drift on a bandsaw refers to the fact that most blades will want to cut in a certain path, which may not be parallel to a fence that is set up parallel to the line that the blade would ideally take. I think the reason is the set of the teeth, among other things. This usually happens during resawing operations where the board is fairly thick (read high) and there is lots of wood to cut out.

   There are really two ways to handle this. One is to attach some sort of point to your fence (a one inch dowel cut in half, for instance) so that the wood rides only on the point. As you resaw you can adjust the board so that the blade always cuts "on the line". The other way is to make trial cuts and adjust the toe-in or toe-out of the fence so that the fence is set up specifically for the drift of a specific blade. This is better for production work and, IMO, produces cuts that require less planing to remove the blade marks.

   John

2. 
   forestgirl | Feb 18, 2003 08:39pm | #2

   oops, John and I were typing at the same time

   Bandsaws tend to cut at a bit of an angle and that effect is called "blade drift."  The blade drift on any given saw, with a particular blade installed, can be seen by conducting the following test:  Draw a straight line on a board, parallel with the long sides.  Cut on the bandsaw, following the line.  Stop mid-way through the board, and look at the angle that is formed between the long edge of the board and the edge of the BS table.  That is the angle of your drift.  If you use a fence, you can angle your fence to accomodate the blade drift.

   Blade drift is affected by, among other things, the type of blade and how well tensioned it is.

   forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl   ;-)

   
   

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   Edited 2/18/2003 12:40:38 PM ET by forestgirl

3. 
   mrles | Feb 18, 2003 08:52pm | #3

   I will try to explain as best I can someone else will probably do better than I. To check drift I would take a 1" X  2" board about 18" inches long, on the 1" edge mark a line in the center one end to the other. Without using your fence saw on your line about halfway through your board. Stop your saw more than likely the board will be at an angle. This is called your drift. You can correct it sometimes by more tension on your blade or if the blade is dull by changing your blade. You can adjust your fence to accommodate your drift if your want to use your fence.

   Hope this helps.

   God Bless

   les 

4. 
   NormInFujino | Feb 19, 2003 01:03am | #4

   Blade drift may be even more apparent on jig saws (saber saws). It's often exacerbated by angled wood grain. Clamp a fence (straight board) to a workpiece at a bit of an angle to the workpiece's grain, and try to follow it with a jigsaw. The blade will tend to bend and "drift" away from the straight line of the fence.

   ". . .and only the stump or fishy part of him remained."

   Green Gables: A Contemplative Companion to Fujino Township

5. 
   user-135888 | Feb 22, 2003 09:56am | #5

   Hi

   I was always under the impression that wood grain has more to do with blade drift than most other things. Higher tension helps, so does feed rate, and the blade you use.

   john