Reverse tooth blade??

[Nancy_G]

What is the purpose of a reverse tooth blade? I have a few of these and the only use I've found so far is to tear the wood apart.
Please notice that I posted this question in the BEGINNERS forum.
Thanks.

I guess there's a lot I don't understand about ANY blades. It seems that no matter what I'm doing or what I'm cutting, I have the best luck (I depend on luck - not skill) with the smallest blade and most teeth.

[BobD]

Nancy,

The way I understand it (but there are lot of people on this board who know a lot more about scrolling that I do) the reverse tooth blade has several teeth at the bottom of the blade facing up. This is to give you a smooth cut on the bottom as well as at the top (like any say blade, scroll saw blades cut smoother one way than another). As for why the wood is tearing out...I don't know enough about scrolling to answear that !

Bob

[Mick Walker]

Reverse tooth blades

Nancy, Bob is right except in reverse. Reverse tooth blades have several teeth at the bottom facing up, all the other teeth face down. You get a smooth cut at both the bottom and top of the wood. The wood is tearing out at the bottom, the blade is dull. Put a new blade in. Mick.

[BobD]

Mick, That's what I meant to say, I just type faster than I think! I've gone back and corrected my post...I just watched a video on fretwork yesterday (a great introduction) and it explained that...


Thanks for the correct, though...Otherwise I look silly!

Bob

[3_M]

They are right about the reverse teeth.
Now about tearing the wood apart. Is it on the top? the blade is upside down. If it is on the bottom you don't have enough sppeed on the saw. Don't go slower than 1/2 speed. 3/4 speed is better. If you use regular plywood, than there is not much you can do about tearing. Use Baltic birch or hard wood.
Also if you don't have enough tension might be the problem. The blade should not move sidesways more than 1/8". Some say the blade should sound like a high C in music.
On my web side I have an article about selecting a blade. It might help to understand the different blades. Being new to scroll sawing a blade with double teeth might be the best for you. They cut slower and you might have better control over the blade.

Mike M

[Max]

Nancy,

Everyone is correct about the purpose of the reverse tooth blade. The tear out problem you have may be due to the saw. If, on the up stroke, the bottom teeth don't come up high enough into the wood, the blades won't do what they are intended. I have a Craftsman saw and only one tooth seems to touch the wood while cutting. I'm not sure if there's much I can do.

You should be able to check this by installing a new blade and cutting a piece of chalk. Then stop the saw and see if there's any chalk on the reversed teeth. That's how I noticed mine wasn't working as I wanted.

Hope this helps.

Dan

[Nancy_G]

Well -I'm not installing baldes upside down and I have the saw set on highest speed. A reverse tooth blade tears thin wood - like aircraft/birch plywood - top and bottom.... thicker wood it, say 1/2" bass wood, it tears the bottom badly.

Oh well -- it's probably "User Error".

[jttheclockman]

Nancy

I can not say I have ever heard of this. It is hard to say user error because you are running the saw wide open. This will make up for the pushing too hard in some ways. What do you cut those same woods with. What type of blade?? Is there an agression setting on your saw?? If it is cutting too aggresivly you do not give the saw blade a chance to catch up. What type saw are you using??

[Nancy_G]

John - You're very kind to pay any attention to me. Thanks.
I'm using a 30" Excalibur, but I can't tell you what size, tooth or brand of blade. I have a huge collection of blades - all fairly old - in a holder and I search for one that I 'think' might do the job.
As I've said before - It seem like I have the best luck with a very small, many toothed blade, no matter what I'm trying to cut.

[jttheclockman]

John - You're very kind to pay any attention to me. Thanks.
I'm using a 30" Excalibur, but I can't tell you what size, tooth or brand of blade. I have a huge collection of blades - all fairly old - in a holder and I search for one that I 'think' might do the job.
As I've said before - It seem like I have the best luck with a very small, many toothed blade, no matter what I'm trying to cut.

Nancy

I guess by now you have found out those saws tend to run slower than most others. They are a very good saw for doing portraits and puzzles because of the near zero back to front movement of the blade. I think then it is a case of you pushing too hard and rushing the cut with a more aggresive blade. With a finer tooth blade you can't do that without breaking it faster. More teeth in the cutting zone would produce finer cut. In real hard woods though it could produce burning. Good luck and use whatever blade works for you. There is no right or wrong choices just prefered choices.

[3_M]

Nancy,

Do have to book from John Nelson "Scroll Saw Workbook"? Would be a lot of help for you. Also, do you know about others scrollers close to you? They could be of some help or you can drive to SD and I will help.
A blade with double teeth might be the best you to use.

Mike M

[will8989]

Nancy, since you were so kind to me about the "threads", I'll try to return the favor. Maybe your blade is to big for the thickness of the wood. If I use a #7 on thin wood I get tearout. I read somewhere the thinner the wood the smaller the blade. This USUALLY works for me. 1/4" to 1/2" thickness I use a #5, this includes stack cutting, 1/2" to 3/4" I use a #7 and 3/4" to 1" I use a #9, etc. I very rarely use a #3 blade but when I have used it it is on less than 1/4" thickness. I also read the thinner the wood, the smaller the blade, the slower the speed. I have an adjustable saw, Hegner, and just adjust the speed as I start cutting until I find a speed that works with what I am cutting. And if the blades are old they may have some corrosion on them (?) that could be causing the prolem. Pitch them and get some new ones from Mike, you won't be sorry. If I call him on Monday, I usually have my blades by Wed or Thurs. Now that's service!! Good Luck!