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+-- Thread: wood drift when i try to resaw on band saw (/showthread.php?tid=7328545)
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wood drift when i try to resaw on band saw - alsayyed - 03-07-2017
Hello everybody
Would any body explain to me why is phenamena. I used my band saw yesterday and have noticed when I have tried to resaw block of wood. The block of wood tend to drift from the fence toward the right side. I have tried several times and still not parallel with the fence. I thought maybe the blade is dull. Dose this happen to you when try to resaw.
RE: wood drift when i try to resaw on band saw - BloomingtonMike - 03-07-2017
Its your blade that is drifting. what kind of fence do you use and can you adjust it for the drift?
RE: wood drift when i try to resaw on band saw - alsayyed - 03-07-2017
the fence is perfect and 90 degrees yes maybe the blade but why is doing that
RE: wood drift when i try to resaw on band saw - Guest - 03-07-2017
There are a few different factors that can come into play. Blade sharpness, the way the teeth are set, the way the blade is positioned on the wheels, the tension the blade is under and the stiffness of the saw's frame.
You should check out The Complete Bandsaw from Workshop Essentials. Excellent and thorough treatise on setting up and tuning your bandsaw for best performance. Many people talk about setting the fence to match the drift. He shows how to tune out most if not all of the drift.
BTW, I'm just a satisfied customer.
RE: wood drift when i try to resaw on band saw - Alan S - 03-07-2017
A dull blade is a likely cause. You need more sharpness for resawing than for other cuts, because you can't take as big a bite at each tooth contact or the gullets will overfill, making the blade deflect. So cutting too fast can also do it. Here's a video explaining: https://woodgears.ca/bandsaw/resaw.html
You can adjust the cutting angle a bit using the tracking adjustment of your saw.
RE: wood drift when i try to resaw on band saw - alsayyed - 03-07-2017
https://www.youtube.com/watch?v=jTjwPo0VtaQ
i have found out this video about drift. and would like to share it with I think this is helpfull
RE: wood drift when i try to resaw on band saw - Huxleywood - 03-07-2017
In general all bandsaw blades with any degree of set in the teeth (as opposed to carbide teeth which are brazed on and ground in situ) will exhibit some level of drift. The amount of set is how far the teeth are "bent" away from the band body. More aggressive blades generally have more set. If the set is even minutely different on one side versus the other the blade will tend to "drift" toward the side with more set. The difference is usually small with a new blade (but still usually enough to drift a small amount, small enough that some may not even notice it) but often gets more dramatic with wear or damage to the blade.
If you understand the alignment of front tires on a car think of the blade as having two tires set with toe out (not normal on a car but no worries) if both tires have the same amount of toe-out the car will track straight, if one tire has more toe-out the car will "pull" in the direction fo that tire.
The general way to account for drift is to adjust the fence, but some people prefer the tracking method described in the video. Be aware the tracking "trick" will NOT work on bandsaws with flat tires but does with crowned tires. Most American and Asian saws have crown in their tires (either from a crown in the tire or a crown in the wheel that translates through the tire).
Drift is just a fact of bandsaw life, it gets worse with wear and it often is worse when doing tall resaws especially on smaller saws that don't have the ideal level of beam strength.
I personally adjust the fence since it is quicker and easier for me than adjusting it with tracking and with the tracking method you are pushing the blade against its natural inclination which I hypothesize will increase blade wear as well as accelerate tire wear, both of which are simply theoretical.
My suggestion is try to ensure your tension is high enough on the blade ( a whole other contentious subject) and adjust the fence to compensate for the drift, but there are more than one way to skin a cat.
RE: wood drift when i try to resaw on band saw - Steve N - 03-07-2017
(03-07-2017, 01:56 PM)alsayyed Wrote: i have found out this video about drift. and would like to share it with I think this is helpfull
The guy he referenced Michael Fortune is a bandsaw genius, and he doesn't believe in such a thing as drift. After spending 2 hours with him I no longer believe in it either. This video guy got it half right, though the part he didn't mention pretty much works itself out in getting the blade to the proper crown. That other thing is perfect blade tension, crowned, and tensioned properly and your blade goes where you point it.
Facts:
The saw doesn't move
The fence shouldn't move once you tighten it down.
Same with the table if it's tight, not going anywhere.
That leaves the blade, and to a lesser extent the guide bushings. When you crown, release all tension on the bushings so you know you aren't "steering" the blade.
Follow the video, and get crowned, so when you make a test cut along a pencil line it is along the line, or just make a cut after setting you fence square to the blade, and use a caliper to measure both ends of that smallish offcut he had after making his test cut. Much more accurate
Once you are crowned, you need to carefully readjust your guide bushings/blocks/whatever. The need to be right up to the blade, without pushing into it. The proper distance is the thickness of a new dollar bill. So they are very tight, yet not "steering" the blade one direction or the other. It is my firm belief after adjusting a lot of BS's for guys who couldn't get a saw to cut straight that this is actually where a lot of
"drift" comes from. I choose to call it steering, because that is what you are doing,steering the blade to a path, you don't really want to go down, so geeeee let's adjust the fence??????? No
After you have the crown right, and the guides correct, check the tension, and make sure it depresses about 1/8 to 1/4" when you push your thumb, or a pencil eraser into it. I like the end if an unsharpened pencil, cause them blades are sharp.
Test cut, if you were careful, and did everything as accurately as possible, you will believe drift is a myth too.
Enjoy
RE: wood drift when i try to resaw on band saw - jteneyck - 03-07-2017
Drift is a sign something is wrong. As some mentioned, you could have a dull blade, a blade with unequal set, or it could be the blade is not tracking properly on the wheels. Adjusting your fence to accommodate drift is something you do only if you don't have a sharp blade to change to. What I'm saying is that it's a temporary solution so you can keep sawing until you get a new or resharpened blade. It's not nor should it ever be a permanent one. Tension and guides are way down the list of things to worry about; they just make things easier.
So do yourself a favor and get a brand new blade, and one appropriate for what you want to do. If you are resawing on a typical 14" Delta type saw, a 1/2", 3 tpi blade is a good choice. Install it on your saw, put a little tension on it, and get adjust the tracking as you spin it by hand so that the back of the gullets are at the center of the upper wheel. Where is it tracking on the bottom wheel? It should be at the center or forward of center. If it's not, you need to check the alignment of your wheels and adjust them to be coplaner. It would be good to do that before you start doing anything, actually. I couldn't get my saw to cut straight until I adjusted the wheels to be coplaner. Some argue this point, but I'm convinced it's key. If the blade is tracking well on both wheels, take the tension up to the tension setting on the saw for that blade, then adjust the guides per the manual.
Make sure your fence is set parallel with the miter slot. Set the fence an inch or so from the blade and make a cut in a piece of wood, 3/4" plywood is good because it has no grain to lead the blade one way or another. Just push it through w/o forcing it to stay against the fence. If the wood stays against the fence and the cut off piece is the same width at both ends, all is well. If the blade wants to pull the work piece away from the fence, adjust the upper wheel so the blade rides a little further back from where it was; do the opposite if the blade wants to push the work piece into the fence. Make small changes, take another cut, and adjust accordingly.
There's no reason to suffer with a bandsaw that won't cut straight.
John
RE: wood drift when i try to resaw on band saw - Arlin Eastman - 03-07-2017
I cut logs to thick wood on mine and use from 3/4" to 1 1/4" blades to do it. Also the 3 to 6 tpi is good for resawing and I always check the tension on the blade to make sure it is right also. Then a lot of guys us a single point to cut wood so they can steer the wood where they want it to go incase of drift