Breaking Blades

[Max]

OK puzzle-heads, I need some help. It's been a long time since I cut a jigsaw puzzle and I am breaking blades frequently.

Here's what I know:

- Table is dead-on at 90 degrees
- Using FD Puzzle Blades
- Delta P-20 running at 1400 rpm
- 1/4", 5-ply birch

The blade is breaking near the center, not near the clamps. Not sure if it's a tension problem, blade speed problem, me speed problem, or what. I've gone through 12 blades and I'm not even half way done with a 5" by 7" puzzle. Any help is greatly appreciated.

[anewscroller]

I would think either tension or speed. I have had to run my saw slower with puzzle blades, because of breakage. I'm not sure of the exact speed, just slower than I usually use for other projects and blade types.

[ubgoofy2003]

I haven't used the puzzle blades that much, but, it sounds like it would be tension, if it is breaking in the middle. They are a very delicate blade, for sure. Hope you can catch the problem before you break any more. Good Luck.

[determined]

Max, It sure sounds like the blade is too tight. Try backing down a notch.
Dave

[Bob Coltharp]

Last year I went through a tough spell for no apparent reason on a puzzle. Couldn't figure out what was going on. The problem went away with no apparent correction on my part. Could have been something I was doing but I wondered at the time if the particular 1/4" baltic birch 5 ply board I was using was a factor. Don't know. Just a thought. Don't get discouraged. I think with time you will also get a better feel for when you are forcing the blade rathere than letting the blade cut and you just guide. I agree that it is probably better to run slower although some puzzle cutters can get by with high speeds.
Bob

[Scrolling Days]

Hi, Dan......could it be that your tension is actually too low? I set mine at almost maximum tension (DeWalt), and in all truth, I haven't broken a blade cutting a puzzle in almost 2 years. The only time I change a blade is when it becomes dull.

Don't feed the wood too fast, either.

If it keeps happening, maybe you just got a funky batch of blades. I doubt it, because the FD SP blades have always served me excellently, but anything is possible, I guess.

[wood-n-things]

While you are cutting all of a sudden stop feeding your work piece and see if the blade continues to cut or stays where you stop feeding. If it has to catch up you are feeding the workpiece to fast and pushing too hard. This will cause your blade to over heat and become brittle and break

I do like Shawn and keep my tension really tight and slow down my feed rate. I too have gone a long time without breaking a blade.

[turtleteasers]

Max,

If you are using 2/0 blades for the first time, you must keep in mind that they are very thin and hence fairly easy to break. You will need to use less tension than you would use for thicker blades.

Having said that, you need to use the most tension that the blade will take, especially for cutting jigsaw puzzles, where you don't want to risk your blade drifting out of the vertical unnecessarily. You should determine the maximum tension that the blade will bear by cranking up the tension while the saw is at rest until the blade snaps. While you are cranking up the tension, periodically "ping" the blade with your fingernail so you know what a fully-tensioned 2/0 blade sounds like. Then back off the tension a little from this setting and try some cutting.

If you can't snap a 2/0 blade by cranking up the tension while the saw is at rest, then you have a problem with the blade clamps on your saw. Either you are not tightening them enough, or they are worn. If you can see a groove in the clamp face, you can file it flat, or perhaps the clamp faces have some oil on them.

If the blade still snaps when you cut, you are probably pushing too hard against the blade. You may be able to get away with this with heavier blades, but the 2/0 is pretty delicate. Take special care not to push too hard, especially in the turns. If you still have problems then you probably need to reduce the speed, but in general you should use the highest speed which still allows you full control of your work, and, along with gentle pushing, let the saw do the work.

Hope this helps.

[Max]

Thanks for all the info. I will start by increasing the tension. The BB ply does seem a little hard so maybe I have a combination of problems. I have some poplar ply seems much less dense and will probably try that also.

On a side note, last year I cut a 12" by 12" puzzle on poplar and only used 3 or 4 blades. At any rate, I will press on, as I have about 50 blades left I should be able to finish this Christmas card sized puzzle (hopefully). Thanks again everyone.

[jim bell]

I have just started doing puzzles on 6mm baltic birch and like you, breaking many blades in the middle. i have it set for the slowest speed and that seems to help. i am using the flying dutchman superior puzzle blade and have actually broken a few when i apply the tension.

it seems the blades dull fairly quickly with this wood. i am going to try using the 3mm boards in the near future, thinking that may solve some of the problem.

[CzechEx]

Hi Dan,

I've got an Ex-30 and my experience on it with FD Puzzle blades is they break at normal tension. I use a lower than standard tension for No.1 blades, and an even lower tension for 2/0 blades. The FD Puzzle blades that I have are even thinner than 2/0. I use speed of about 600 - 700 opm, and habitually cut 4mm 3-ply birch. This has been working fine for a long time. I find if the tension is too high I also loose a lot of smoothness in the turns.

All the best,

Karsten.
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