Thread: Bandsaw - problem with wavy cut

Feed rate and tension. Possibly also too much set on the blade. Have you compared with another blade?

Regards from Perth

Derek

Thanks Dereck.
Old blade was same thickness and tpi, but not bimetal. It never did the wavy lines cut.
I've tried the "flutter tensioning " of the blade and the Alec Snodgrass method.
I've tried quicker and slower feed.
So new blade has wavy cut after different ways to set up saw.
I'm inclined to think it may be the blde set as you suggested.
A mate is coming down tomorrow to check it out.
Hopefully he'll find something obviously wrong.
Or it's back to the place where the blade was made to see if they can help.
Thanks again

Another thing to consider is a blunt blade even if it is new.

Thanks Chris.
I don't know that the blade would be blunt. It was made at a reputable saw service.
It cuts really easily, just wavy...
Thanks
Lyle

The cedar looks like you’re cutting along the grain or with the grain, and the tas oak it looks like you’ve cut across it. But I’m only looking on my phone so I could be mistaken but the cedar looks like the end grain is at the top ����♂️

Thanks riverbuilder.
Cutting along the grain.
Only difference was depyh of cut.
I used a decent fence too.
I'm still snookered.
Lyle

I have a bimetal blade on my b/s and get similar cuts at times.
I think that a b/m blade is not best suited for smooth cuts in all jobs.
One of my first jobs with my b/m blade was a mallet; and some of the thicker cuts had similar teeth marks.
Now I do test cuts if the job is important or don't have much of the wood, and change blades if required.

3tpi, I wasn't expecting smooth cuts. I knew that I would need to do some finishing, but not this much.
I got this blade to make thin boards for veneers.
I think that I have ruled out the machine for now.
Lyle

put up a video of you operating and the saw in action. it will be easier this way.

you can get good result from average saw but very good blade
you WILL get not so good result from a below average blade on a very good saw.

I think its feed rate and tension.

Good morning Lyle, given that you are happy with the sharpness of your blade, and considering that a 3tpi should be fine for that depth of cut, I would also suggest that you're either feeding too fast, or that you don't have enough blade tension.

When I first started re-sawing, this video helped me understand how too fast a feed rate (or high tpi blade) would produce wavy cuts.



Having said that, the only time I see wavy lines like yours is when I'm using a 1" blade that my bandsaw has trouble tensioning. I would love to see an explanation of why insufficient tension causes such a cut though to understand what's happening.

Thanks LanceC. Good video.
I think my saw is ok re power.
While I wait for my mate to get here, I'll try and check it all out again.
Tension, guides etc.
Then try feed rates again.
I'll get there eventually.
I don't have capability to do video.
Lyle

Try cutting the cedar the other way, across the grain.

Well, my mate came around.
He watched as I took the saw back to basics.
All guides, table, etc backed off. Blade run on the top wheel crown correctly.
Guides re-positioned, blde re-tensioned.
Cuts much better now. Finish is as I expected from a 3tpi blade.
Cuts square and parallel now.
Now to restrict my feed rate. Not too fast......
Thanks to all for your helpful suggestions.
Lyle

One of the tricks of the trade is to push with a push stick, your grip should be at the back of the stick and you should push the gripping hand with your hip or gut. This technique will slow your feed rate and make it vastly easier to feel the natural feed rate, & that in turn will lead to a much smoother steadier in feed which will help with the quality of the cut.

Normally when I see that rough sort of cut, it is a nick in the blade, a kink in the blade or a bit of crud built up in one spot on the tire