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I have a 24 inch ECE bowsaw and everytime I use it won't track a line. I am right handed and everytime the blade tracks waaaay left. This doesn't happen with I use any other hand saws, just the bow saw. Does anyone know of the most common mistakes when using a bow saw so I can try to eliminate a few of the possibilities? Thanks!
check the set on the left side.
you don't say whether you are ripping, crosscutting or scrolling,
crosscuting
When I look down the blade I can't see any more set on the left or right. Is there another way to check?
easiest way to eliminate the blade is to turn the saw around and use it on the pull or push stroke (the opposite of what you usually do). If it pulls right it's the blade if it doesn't it's probably your technique.
I find bows saws can be a bit tricky if you try to employ the techniques usually unconsciously employed with regular saws. What I mean by that is on a regular saw you use the deep blade depth to gauge if the saw is at a 90 to the work and therefore cutting straight. It's something most would do without realizing it. If you try the same technique with a bow saw you end up tracking off right or left because often the blade isn't 90 degrees to the work even though the saw frame is. You have to watch the cut and ignore the frames position and or angle relative to the work piece and adjust accordingly to what the cut is doing.
Brian,
Are you talking about making sure that the blade is inline with the frame?
Aaron
Zoom in on the bandsaw blade with your mind's eye, and imagine the set of the teeth magnified and exaggerated. I'll assume you're right handed. If you push outwards (i.e. to the right) even a little bit as you're sawing, the set of the teeth will push the saw to the left. With something as flexible as a small bow saw blade, the blade will very happily twist and drive the cut to the left. The teeth contact the wood before the back of the blade, allowing the blade to twist.
Take a piece of wood, maybe 6" wide and 1" thick, and try to resaw it. If the back of the cut is sorta straight, and the front (part nearest you) of the cut goes left, you MAY be pushing on the saw sideways. I had that problem years ago when I first tried to use a bow saw, and I found it actually pretty difficult to correct for whatever reason.
I'm not saying this is the problem. I'm a novice bow user. It's just a particular problem that I had.
Iffen your trying to use a bowsaw as a rip saw, with the blade 90° to the frame, there is a lot of weight hanging on the right side that you need to counter or account for, its not like using an ordinary handsaw to rip with where there is no weight hanging off either side. That's why I use a Frame Rip Saw to rip with instead of a bowsaw which was meant for crosscutting or doing scolling work.
Bow Saw for crosscutting,
http://img.photobucket.com/albums/v8...od/bowsaw2.jpg
Bow Turning saw for cutting curved work,
http://img.photobucket.com/albums/v8...od/bowsaw3.jpg
Framed Saw for Ripping.
http://img.photobucket.com/albums/v8...rameripsaw.jpg
FWIW, I use all my saws in dry lumber, and I rough set them after sharpening, then using a smooth jawed machinists vise from a school auction, I use a piece of copy paper folded in half and clamped in the vise jaws fold down, then bend over the parts sticking out and tape them to the jaws, then clamp the saw blades between the paper lined jaws to get an even narrow set on each side of the blade. They cut quicker and don't wander only very little because of the narrow even set, the teeth cut thru the paper, they will not work in green or wet wood tho.
You will likely not see the difference in the set even if it is the cause.Quote:
Originally Posted by Aaron Hall
If your blade is wide enough, use a small square when starting the cut to make sure the blade is at a right angle to the work.
If all is correct, then the set could be causing the drift. The easiest way to look for and correct something like this is to take a dry oil stone and rub it down the side of the teeth of the saw on the side it has a tendency to wander toward. Just one rub and do not put a lot of pressure on the stone.
Then do a test cut. There should be some change. If no change, try again.
If it changes a little, you are likely on the right track.
I am not a bow saw user, so I can not offer much more than this.
jim
Quote:
Originally Posted by Aaron Hall
Reversing it is more to determine if the blade has little or no set on one side.
First off, these bow saw blades are thin. As a result, the kerf is probably thin as well, unless it is a turning blade. A single tooth sticking out too far can cause amazing drift.
If you are cutting a quarter of an inch per stroke, and you are cutting through a 1" x 8" board, it takes 32 strokes to cut. If you have one tooth sticking out a 32nd of an inch then the saw is likely to drift a 64th of an inch in the direction of the stray tooth, with every stroke. This means you will get a half inch drift by the time you get to the end of the board.
The actual drift will be even worse due to the change in angle of the blade. The way to fix this is to Stone the blade.
Here is a fairly easy way to precision stone your blade.
Make a flat sanding block by gluing down a full sheet of fine sandpaper to a block of mdf. halfway cover the sanding block with a thin stack of paper. lay down the flat of the saw on the paper where the teeth hang off the edge of the paper. Reduce the sheets of paper in the stack until the teeth just barely touch. Now slide the blade on the stack of paper so the teeth are sanded even on the side. Flip the blade over and do the other side.
Doing this will fine tune your blade and if done with fine enough sand paper, it can polish the kerf so that you can cut much smoother cuts.
Any time you snag your saw on a knot or hit a nail, you may need to do this to tune up your saw.
Bob
Aaron - You don't say what type of ECE bowsaw you have. Adria's site lists several:Quote:
Originally Posted by Aaron Hall
http://www.adriatools.com/ece/saws/bowsaw.html
If you have the "crosscut" version you will likely not be able to do much with the set because these are Japanese-type crosscut teeth with an exceptionally complex geometry, and their tracking is dependent on considerably more than just the set. If the fleam angle for the top chisel point was ground incorrectly from one side of the blade to the other, for example, then the saw will not track straight no matter the set.
If you have a turning saw, realize that these have very narrow blades that aren't meant to track a straight crosscut line automatically - you have to steer the saw with each stroke.
Finally, while Europeans tended to use tensioned bow saws for cross-cutting, British craftsmen preferred panel type saws with wide saw plates and simple tooth geometries. I suspect this might be part of the reason.
Gentlemen,
Thank you very much for all the info. This forum really is top notch, IMHO. When I turned the saw around and used it as a pull saw the cut was very difficult to start but I didn't notice any wandering, so I'm thinking it's my technique.
John C.
You made an interesting point about pressing the saw to the right as I cut. Perhaps this is part of my problem. Tomorrow, if I get some shop time, I'll practice a bit more.
David K,
http://www.traditionalwoodworker.com...oducts_id/2037
Thanks again, folks, I really appreciate the help.
~Aaron