Drilling holes and inside cuts

[Jim Rodman]

Hi
Two question about cutting patterns
-Where you drill blade holes.
-And when inside cuts are close together.

When I drill holes for inside cuts . The back side of the wood is not a
clean hole the wood fractured. Would this be caused from to slow of a speed .
How to keep this from happening, have a backer board that you drill into.

when the inside holes are very close together pieces of the wood between the holes
chip out. The stock that I an using is Baltic Birch. Do you have any solutions to
keep this form happening.

Jim R

[William Young (SE BC)]

Hi Jim;
I think you basically answered your own question.
Very high speed for drilling those small holes and a backer board should solve your problems.
Rule of thumb for drilling is the smaller the bit the higher the speed. I have a 16 speed drill press and when I am using those tiny drill bits it is set on speed 16and cuts through the wood like cheese with clean holes top and bottom.
On the other hand , when I am drilling 2" or 3" holes with forstner bits I use the slowest speed.

For the second part of your question I am not sure if you are referring to drilling or sawing . If it is in regards to sawing you need to use a blade with reverse teeth on the bottom end. The top choices on the market for them seem to be Pegas and Olson and FD. You may also be using too thick a blade . A finer blade with more tpi should solve that problem. Take your time and let the blade do the cutting and you should be fine.

W.Y.

[PeteB]

Jim,

You didn't say what diameter drill you're using, but probably 1/16" would be best most of the time unless you are making very fine cuts, in which case you'll want to refer to your blade specs to see what the minimum hole diameter must be. Very small drill bits like these shouldn't cause much tear-out, if any.

Also wanted to mention that reverse blades don't work well on single thicknesses of thin wood, like less than 1/2". If you are cutting 1/4" BB, a regular 2/0 skip tooth blade will polish the edges very nicely and leave just a bit of fuzz on the bottom that will knock right off with 180 grit paper.

Pete

[Marsha]

When drilling entry holes for fret work, I don't understand why tearout is an issue. It's just an entry hole and the piece with the tearout will be cut away. Unless you're drilling so close to the cut line, that the tearout is on the cut line, then I would suggest a smaller drill bit.
Not much help, just an observation.
Marsha

[sawdustus]

Jim,

Small bits use high speed
A backer board helps a lot
Don't drill too close to the cut line (sometimes impossible)

I would add:

As you near the end of the hole, don't force the drill press downwards. Ease up on the pressure as your drill bit breaks through.

USE SHARP BITS. - These little guys as cheap enough to throw away rather that trying to extend their life or resharpen them.

[SharonW0111]

to prevent tear outs in drilled holes-- place a scrap piece of wood under your project- then let the drill bit go into that -for some odd reason this will prevent tear outs- and as far as holes to close together -- try to make sure you can keep them a safe distance from each other-- this is easier when sawing too
Sharon

[Jediscroller]

Originally Posted by Marsha

When drilling entry holes for fret work, I don't understand why tearout is an issue. It's just an entry hole and the piece with the tearout will be cut away. Unless you're drilling so close to the cut line, that the tearout is on the cut line, then I would suggest a smaller drill bit.
Not much help, just an observation.
Marsha

Jim,
You've already gotten good advise so I'll leave that alone.

Marsha,
To answer your question, I often cut patterns where the drill bit size is essentially the same size as the cut out and the bridge between the cuts is smaller than that so it can be an issue with very intricate patterns.

[MikeDingas]

Could saw speed be a factor in the tearout? I, too, use a Craftsman 16" VS and normally have the speed set at less than half.

[Minnesota scroller]

Mike, you must be experiencing tearout while cutting. I don't see how the saw speed can be relevant. I used to use a Dremel and always had the speed set at half or below. If it's a problem, you should try reverse tooth blades. I use pretty much all regular skiptooth because portraits are my thing. Portraits require a backer so tearout isn't an issue here. I just take my palm sander over the back afterwards and anything else will never be seen.

[Rivari]

My two cents...

If you are experiencing tearout could the problem possibly be that your work is chattering? When your sawing be sure your work is staying flat on the table top.