Jumpy wood

[Rev. Redmond Farrier]

No, I do not mean that I am making the wood nervous with my poor skills.
For practice, I drew out a puzzle on a bit of scrap plywood that I found. When I neared the end of the piece, the wood started jumping quite often and the blade would kick back a cm or so into the line I had just cut. Any ideas as to what is going on here?

I also have another little issue with my saw. When I turn it on, I almost always have to push on the arm to get it started moving. I have a 16" Craftsman. Any clue as to what is going on here as well?


Rev. R. Farrier

[CanadianScroller]

Wood will jump if the blade is dull or too coarse. It will also jump if it binds as you turn sharply.

Try a good selection of blades and find out what works best for you.
Check your blade tension too.
As for the saw needing a kick start, it may need servicing. That isn't normal, try oiling the bearings or bushings. You should be able to pick up a maintenance manual from craftsman

[workin for wood]

I often have that problem of needing a pump start on my Hawk G4. They said dust gets in the switch, blow out the switch. How that relates is beyond me, as it still needs a boost, and I do oil it which seems to help although it isn't supposed to need to be oiled.

Usually when wood kicks, it's too tight a turn or the blade is upside down. Been there done that.

[Pajaro]

Jeff may have the right answer the blade upside down. The bigger the blade the bigger the jump. Not as bad with very fine blades.

[Rev. Redmond Farrier]

I have the teeth pointing down, is that the right way?

Rev. R. F.

[Neal Moore]

Yes, the teeth should point down. Reverse tooth blades have a few teeth on the bottom of the blade that point up so the kerf is cleared of dust as you saw. "Chatter" is a common problem among new scrollers, I think everyone has experienced it to one degree or another early on. It's worse with reverse tooth blades until you get used to using them. It's just a matter of practice and feeling how much pressure you need to keep the wood from chattering on the table while at the same time controlling the cut. The big secret is to let the blade do the work and don't try to feed the work into the blade too fast.

[ragiarn]

I have had my piece jump as a result of not holding the piece down firmly. It happens at times when I am not concentrating as much as I should or getting to the end of the cut and begin to subconsciously letting up.

Doc

[minowevie]

Gosh I don't know about the arm not moving, maybe ,,,just maybe, could it use some oil in the moving parts. Or, is the hole you are drilling to small for the blade. probley not, that might make the wood jump not move,
any way. the wood jumping is a common problem like Neal says. what I do, is hold the wood down with my left hand, or fingure, close to the back of the blade, guiding the feed with the other hand, If you don't hold that wood down, it can slam dunk your hand and sometimes fingures and scar the beheegies out of you. anothe problem is warped wood. you really have to hold it down then, it wonts to jump all over the place. don't worry Rev. it is all in the learning that we all do. and still do often. your in the right place, your friend Evie

[Rev. Redmond Farrier]

Thanks all for the advice here. I hope to get out there and try it again later today if I can withstand the heat. (this is the beginning of my least favorite time of year lol)
I bought some blades at Home Depot today. I still don't know much of anything about blades, but I think these blades should do much to help me with control of the piece.
I also figured out what that little metal pipe that was in the bag with the blades is for. It hooks up to the top of the device to blow away the saw dust! lol It would be nice if I had some sort of manual for my saw. Having never seen one of these saws before I pulled mine out of the shed, I am having to do a lot of trial and error to figure it out. (and I am enjoying nearly every moment of it)

Rev. R. Farrier

[Jim McDonald]

IF cleaning and oiling the pivot points don't get your saw working without having to push it (sound like an old treadle sewing maching my grandmother had), the problem could be a bad starting capacitor in the motor.

When motors start, they can draw anywhere from 1.5 to 3 times the amperage rating on the UL plate. To help counter this, many companies will put a decent size capacitor in the power line to store and deliver this initial surge to kick the motor into gear without the escess draw and heating that could occur in a standard motor. Most non-capped motors come to speed more slowly and don't need the sudden jolt of electricity that scroll saw motors require to instantly come to speed and torque.

If the capacitor (cap) is bad, you can find replacements at electronic parts dealers. Try to match exactly, but if you have to sub, make sure the working voltage is the same or higher and the capaticance is close to the same in microfarads, abbreviated uF.

A bad cap will probably be discolored and may appear to have a tar-like substance leaking from one end cap or a seam. It is not highly caustic, but can be messy if you get it on you. Also, it may smell burnt since the "magic smoke" is no longer contained in the can.
You might be able to find an exploded diagram online to show you where the cap is located, but generally it is near the switch or attached to the motor.

Loks of luck.