Will it work to use a 1/8 inch square broach, such as is sold by MSC, to
make a square hole in acetal (Delrin)? About 1/2 inch thick. Or will it
just tear up the acetal? I haven't worked with acetal. I'm reluctant to
spend 70+ bucks on a broach if it isn't going to work. Is there any other
way? I will have many of these to do.
Thanks for your kind advice.
Will-it will work great. Bear in mind that square broaches, at least
all the ones I've used, require a pilot hole slightly larger that the
dimension across the flats. So you don't get a completely square hole.
Each side has a little in the center removed. Use water or water
soluble oil as a cutting fluid.
Would one of the less expensive square hole bits work? There are two kinds, one
is a geometric figure with one less side than the hole wanted: three sided
rounded triangle drills square hole.
The other is the woodwoorking item, an auger down the middle of a square hole
shaving bit. 1/8 is very small for this. And you have to have the bit holder
for your drill press model. I have one in 5/16.
The square broach, if you wish to spend the money, will produce good results.
You may be able to press it with a drill press, but ideally an arbor press will
provide more control.
Have you considered turning the end of a 1/8 square rod and pressing it into an
undersized hole? Do you need a lot of torque resistance? You might spline the
end of the rod on a lathe by moving the carriage by hand as a planer would
move. Or is it a shaper? It's a shaper. I was wrong. Why don't I go back and
edit that? Maybe I will. Ok, I'll just.....
Doug Goncz, Replikon Research, Seven Corners, VA
Unequal distribution of apoptotic factors regulates
embryonic neuronal stem cell proliferation
Drill a smaller hole, then use a piece of 1/8 keystock heated with a torch
and plunge it thru. Grip the keystock in a drill press to make the hole
straight. IIRC most varieties of acetal handle remelting fine...
If the hole ends up oversize, for the next one make the keystock punch