Susumu Mori
09-06-2014, 8:11 PM
Hi all,
Since I upgraded my Griz 14-inch to a Felder 20-inch bandsaw (FB510), I started a lot of resawing. Now it truly widens my woodworking capability and is quite a joy to use.
Anyway, I'm still learning how to use this larger bandsaw and resaw wide boards. I would appreciate if you could shed some lights on my experience here.
The first thing I did with this new BS is, of course, I measured drift. I didn't see any. If the fence is parallel to the table, I can get a veneer of consistent width. If I check the drift in the way Laguna explains in their website (cut a board little bit and adjust the fence angle such that the back end of the blade is in the middle of the kerf), the back of the blade is slightly tilted to the right, but I ignored it.
Now, here is the interesting part. If I observe how the blade behaves very carefully during resaw, as soon as the blade is pushed against the thrust bearing (and the bearing starts to turn), the back of the blade is deflected to the left and sometimes touches the wood at the left side of the kerf, leaving some dark mark coming from the blade (maybe I should clean the blade). This is sort of understandable because as the blade is pushed against the thrust bearing, it has to deflect to the right or the left. I think that's natural.
Maybe the side bearings are suppose to catch the deflection and move it back to straight. My Laguna 1" ResawKing has 0.04-inch kerf. So, I'm talking about 0.02 inch of deflection. Because the Euro-style side bearings are slightly toe-in (narrower in the front and wider in the back), it doesn't prevent the deflection (according to MiniMax bandsaw manual, this toe-in configuration is intended, probably to enhance the bearing rotation).
The most puzzling thing is, if I do not use the thrust bearing, the bandsaw still cuts just fine. It is less nosier because the blade makes a shrieking noise as it scratches the thrust bearing. also, the kerf becomes slightly thinner probably because there is less force to tilt the blade. That's all I noticed. The veneer came out just fine.
OK, I just tested using a 6-inch board. Things could be different with a 10-inch board.
But if I think about it, I'm not sure if it is a good idea to push a BS blade to the bearing. The fact that the flexible blade is deformed to reach the bearing means, it is likely to keep finding a direction to deform after pushed against the bearing, right? OK, if there is no thrust bearing and we push too much, the blade may come out the tires. If that is the role of the thrust bearing, I would just set it maybe 1/8 behind the blade and as soon as I hear the blade touching, I slow down a bit. At least, I'm not sure why the bearing has to be right behind the blade.
If there is a reason that the thrust bearing really need to support the back of the blade during the cut, I guess the Carter-type bearing with a groove may make a sense. Or Laguna-type side support that keeps the entire blade length straight sounds a good idea. But if everything goes well without it, that sounds a good solution too.
In any case, if you could give me any advises, suggestions, or experiences, I would really appreciate it.
Since I upgraded my Griz 14-inch to a Felder 20-inch bandsaw (FB510), I started a lot of resawing. Now it truly widens my woodworking capability and is quite a joy to use.
Anyway, I'm still learning how to use this larger bandsaw and resaw wide boards. I would appreciate if you could shed some lights on my experience here.
The first thing I did with this new BS is, of course, I measured drift. I didn't see any. If the fence is parallel to the table, I can get a veneer of consistent width. If I check the drift in the way Laguna explains in their website (cut a board little bit and adjust the fence angle such that the back end of the blade is in the middle of the kerf), the back of the blade is slightly tilted to the right, but I ignored it.
Now, here is the interesting part. If I observe how the blade behaves very carefully during resaw, as soon as the blade is pushed against the thrust bearing (and the bearing starts to turn), the back of the blade is deflected to the left and sometimes touches the wood at the left side of the kerf, leaving some dark mark coming from the blade (maybe I should clean the blade). This is sort of understandable because as the blade is pushed against the thrust bearing, it has to deflect to the right or the left. I think that's natural.
Maybe the side bearings are suppose to catch the deflection and move it back to straight. My Laguna 1" ResawKing has 0.04-inch kerf. So, I'm talking about 0.02 inch of deflection. Because the Euro-style side bearings are slightly toe-in (narrower in the front and wider in the back), it doesn't prevent the deflection (according to MiniMax bandsaw manual, this toe-in configuration is intended, probably to enhance the bearing rotation).
The most puzzling thing is, if I do not use the thrust bearing, the bandsaw still cuts just fine. It is less nosier because the blade makes a shrieking noise as it scratches the thrust bearing. also, the kerf becomes slightly thinner probably because there is less force to tilt the blade. That's all I noticed. The veneer came out just fine.
OK, I just tested using a 6-inch board. Things could be different with a 10-inch board.
But if I think about it, I'm not sure if it is a good idea to push a BS blade to the bearing. The fact that the flexible blade is deformed to reach the bearing means, it is likely to keep finding a direction to deform after pushed against the bearing, right? OK, if there is no thrust bearing and we push too much, the blade may come out the tires. If that is the role of the thrust bearing, I would just set it maybe 1/8 behind the blade and as soon as I hear the blade touching, I slow down a bit. At least, I'm not sure why the bearing has to be right behind the blade.
If there is a reason that the thrust bearing really need to support the back of the blade during the cut, I guess the Carter-type bearing with a groove may make a sense. Or Laguna-type side support that keeps the entire blade length straight sounds a good idea. But if everything goes well without it, that sounds a good solution too.
In any case, if you could give me any advises, suggestions, or experiences, I would really appreciate it.