Scrollsawing Question

[Kevin Daly]

I just completed cutting an intarsia pattern of a hummingbird and flowers. I was using 25 tpi blades that the package said were for extra sharp turns and marquetry in soft woods up to 3/4". In the process of cutting out the pattern, I broke 6 blades (3/4" pine). Is this normal or am I doing something wrong? They were craftsman pin-end blades. Are there better blades out there? I have plain end adapters for the scroll saw (older Dremel 16" 2 spd). Any help would be greatly appreciated.

Kevin Daly

[macyver]

Don't know if this helps But I too am breaking an inordinate amount of blades. I use American vermont blades. One thing that I did to slow the blade breaking process was to check the tension of the blade and control my feed rate better. This seemed to help a good bit. I also use the thinnest blades for intricate turns. Spiral blades are great for tight turns but if your not careful you can mar your stock. And if anyone out there is reading this, why does it seem that my scroller blade always want to twist? It seems well it is that I am having to push to the 11 Oclock position to stay straight?

I hope we both get the help

[Bruce C.]

Slow down, it takes practice.

After a while you'll be able to select the appropriate blade for the job based on experience. Check your blade allignment, it should go straight up and down (from the side and from the front). If the blade has an angular movement, you are likely to break more blades. Slow the motor down too (if you can). Generally speaking, good plain end blades are better than pin end.

Start with courser blades and work toward finer blades as your experience increases. You'll know you're there when you wear out more blades than you break.

Yes it is normal for the blade to cut straight at about 11 o'clock. The blades are machine cut with a burr on that side - better quality blades have a smaller bur or none at all.

[Silvan]

Me three. I seem to break six blades on every piddly little project, and I'm already feeding the work really slowly, with the motor dialed down to its lowest speed, being careful not to crowd it, and making sure the blade is only just twangy tight.

I feel like I'd break fewer blades and be able to cut two or three times faster with a coping saw. My crawl saw is my least favorite machine by far.

[Bernard Randall]

IMHO I think that is far too many teeth for that thickness of wood, the problem you face is you can't get the waste out efficiently so most of the teeth just clog. As a matter of interest take a short cut of say an 1" and then feel how hot the blade is; it gets too hot and it loses its temper. The other thing you need to watch is how much pressure you are putting on the blade, those type of blades can't take much pressure.

In your position I would do some experimenting, first try much thinner wood and gradually work up in thickness, also try different tpi.

Bernard R

[George]

Best answer. And a lot fewer teeth may be the case at faster speeds. Pine is also a bit resinous at times, which puts an additional drag on the blade.

As to breaking, the most common cause I see with the kids at school is they are turning without feeding. Even with the narrowest of blades, that's a recipe for disaster. Anticipate direction changes and lead them for best cut and least strain on the blade.

[Roy Neudecker]

Kevin,

Same reply as the others who have gone through this before. Slow down! Let the blade do the cutting. The blade needs to cut the stock you cannot push the blade through the stock. The more you push the more the blade heats up from friction that weakens the metal. Finer blades are good but they need longer to cut through thick pieces of wood. The reason they said that that blade was good for marquetry is that they are talking about the blade going through thin pieces of stacked wood. The finer blade would cut the edges cleaner (smoother). But you are going through 3/4" solid pine. You could use another blade and do better such as a reverse skip tooth with fewer teeth per inch. Just remember the fewer the teeth the coarser the cut. So you don't want to go to few of teeth.

Roy

[Roy Neudecker]

Rich,

This is caused by two problems. One is the saw the other is the tension. It sounds like you have experimented with tension already so it may be the saw. Less expensive saws present the saw at an angle to the stock. That is the blade does not travel straight up and down. So what happens is the leading edge that has the pressure on it from you pushing against it will deflect to one side causing it to not cut straight. See if you can make any adjustments to compensate for the blade travel. If not you will have to really slow down the cut. More agressive blades may help a little too.

Roy

[Tim Schubach]

One other thing I've found that works for me, especially in hard woods, is to use packing tape on top of the pattern ( even if you've already used some kind of contact cement to hold the pattern down ). Sometimes, I even put tape on both sides of the wood. The tape helps lubricate the blade a little bit, but it will not help with chip/dust removal.

I've had a lot of luck using this method on similar projects. Look at the very bottom of the page at

Both of those were cut from 3/4" ash.

Good Luck, tms

[Pop Rivet]

...

... Well, I'll be danged! I thought it was just me! :-{} I never considered asking anyone about it - just figured it was either my fault of the saw was screwy somehow. You won't believe how many times I've tried to see if the blade was straight, twisted, out of alignment, dirt in the holders, etc etc etc..

Learned something: Guess I can go back to bed now!

Pop

[Kevin Daly]

Very nice work. I've got a way to go to get to that level, but I can hope.

Kevin Daly