Frame saw chatter

[Steve Demuth]

I have a frame saw with twisted string tensioning that I made for the Japanese 400 blades sold by Highland (https://www.highlandwoodworking.com/turbo-cutbladeforclassic400framesaw.aspx). Love the blades in general, but I get a lot of chatter in most cuts, and particularly when nearing the end of a cut.

I don't thing I'm undertensioning with my saw design, but can't be sure.

Any ideas what I may be missing?

[William Fretwell]

When the blade is warm apply some beeswax see if that helps.

[Patrick Chase]

I have a frame saw with twisted string tensioning that I made for the Japanese 400 blades sold by Highland (https://www.highlandwoodworking.com/turbo-cutbladeforclassic400framesaw.aspx). Love the blades in general, but I get a lot of chatter in most cuts, and particularly when nearing the end of a cut.

I don't thing I'm undertensioning with my saw design, but can't be sure.

Any ideas what I may be missing?

I use that exact blade in the 400 mm saw that Highland sells with metal rod tensioner. I also use a very similar blade in the Nobex frame saw that came with my miter box, also with a metal rod. I use both on the push, which is presumably not what the blade and its toothing were designed for, but it works for me in a heavily tensioned framesaw (and note that some modern "Western" dispose-a-saws like the Bahcos have similar triple-beveled toothing). I keep meaning to replace the metal rods with twine and a toggle, but haven't gotten around to it yet.

I don't experience chattering, but that is an aggressive blade with slightly positive rake, so it can bind if you push down too much (or at all) particularly at the start of the cut. Could that be what you're feeling?

[Steve Demuth]

I don't experience chattering, but that is an aggressive blade with slightly positive rake, so it can bind if you push down too much (or at all) particularly at the start of the cut. Could that be what you're feeling?

Could be. I have been using it on the pull stroke. I'll give it a shot the other way 'round and see if I can get a bit more tension on the blade.

Thanks.

[Patrick Chase]

Could be. I have been using it on the pull stroke. I'll give it a shot the other way 'round and see if I can get a bit more tension on the blade.

Thanks.

There's no way you'll get more tension pushing than you do pulling. It is roughly valid to say that pulling adds to the frame's tension, while pushing subtracts.

I suspect that your issue isn't tension-related to begin with, though, which is why I asked about cutting direction. The pressure/cutting angles are different between push and pull, and some people will find one easier than the other (it varies by the individual).

[Steve Demuth]

Patrick,

Yes. Poor wording on my part. I didn't expect more tension on the blade from pushing, rather was trying to say I'd see if a bit more frame tension from the twist would help.

[Pat Barry]

I'm really not sure what you mean by chatter. Do you see the effect of this chatter in the cut quality or just sense the chatter in your hands as you cut? As far as tension goes, there is little downside to more tension except what your frame can tolerate. Wider blades (either thickness or width) need more tension than skinnier blades. Lack of tension could result in blade vibration and that will be dependent on the force applied, the speed applied, the tension, and the position of the cut on the blade. If you are feeling vibration as you cut and it gets worth toward the middle of the blade then I would think the blades is vibrating and this may be what you are feeling. Going slower, if you already have enough tension, should help. Push or pull shouldn't really matter too much with a frame saw, since I would argue, the blade itself doesn't know the difference and that's what really matters - this is different with a non-frame type saw.

[Mike Holbrook]

I have a “Universal” Turbo Cut blade in my 400mm frame/bow saw. The Universal blades tend to vibrate/ chatter more than the blades designed for ripping or x cutting.