Looking for Tooling

One tooth fly cutter style without a center for a plug to get stuck in at all?

So, how about a hole saw with a springloaded Delrin piston to eject the waste? The work is only 1/16" thick, so there's plenty of room inside a standard hole saw for the works.

Add to that, use something resembling a flat faced, spring loaded live center to stabilize the cutout during cutting if needed.

You beat me to it. I've used this:

similar things. Best used with a pilot shaft instead of a drill for best results. Drill/punch pilot hole BEFORE trying to chew out the big slug. Slooow rpms. There was also a similar item with a counterweight for sale at one time, think it was Brit. Tolerance is as good as you can set the thing up to.

Alternative is some sort of punch, chassis-type for low production, arbor/hydraulic press setup for medium, regular punch press for large.

Stan

Another thought, if you need to better manage the cutout pieces in an automated setup would be to hold the cutout with a vacuum from underneath, and at the end of the cycle swing that lower support down with a pneumatic cylinder, release the vacuum to drop the piece, and then swing it back up and reapply vacuum for the next cycle. Would seem to work well with your pneumatically powered drill rigs.

Not worried where the plugs go. It's a manually loaded part with a trigger for the drill process. But it's like a drill press on steroids in that it will never be turned off while they are drilling parts and has enough thrust to crush the part...

I'll manage the feed, RPM and thrust rates. It's all about that plug.

Forstner bits were suggested by the woodworkign folks, but I'm afraid that the plug may stick to the center pilot even on that set-up.

Tests to follow. We shall see...

As for the other custom tool ideas discussed here already - too fancy for the customer "me thinks"... They want an off-the-shelf, inexpensive oepration for a downa nd dirty, low tolerance required hole process.

I don't think he would care if the plugs ejected 10' away as long as he could put up a wall to stop them. :)

I'm pretty sure that single tooth cutters are not custom tools. Outside of that, it sounds like they might be better off with some sort of punch setup.

Try grinding the set off of the teeth on the *inside* of the holesaw. It's just a guess, but that may eliminate the drag when the slug tries to fall out.

Maybe. But it's a cheap and quick thing to try.

Nope, that won't work unless you leave one tooth unground, otherwise you simply increase the diameter of the slug to match the ID of the saw and it will still hang up. With one tooth left unground, or a single tooth cutter as I noted, you cut the same smaller diameter slug, but since there is only a single tooth on one side that diameter, the slug can shift away from it and fall out easily. One tooth cutters are also not custom tooling, I've seen them before as standard items, with a standard round body and a single carbide tooth. In either case, you don't use any sort of center drill in the saw since you don't need that pilot in a rigid machine.

Punch and die? Even a little air press would do the job.

See my sig file below. That would be detrmiental to my relationship with this customer. :)

Agreed. Hougen (and some others) make "stack cut" hole saws that cut the ID differently than a standard annular cutter for the same basic reason.

However... The idea of a pilot in this case is to provide an ejection system. A pilot that is sprung when drilling will pop the plug out when the material is drilled through. ...But all of the plunger-equipped cutters are equipped with pointed or small round plungers. I am looking for a plunger that is slightly smaller than the ID of the hole saw... That would help greatly "me thinks."

...Not an over the counter product as far as I know.

You're missing the point...

The only ways that the slug can become hung up in a pilotless hole saw is if there is a position within that hole saw that is the same width as the slug. With a one tooth hole saw, this is impossible since the slug is smaller than the inside of the hole saw, even at the smallest dimension i.e. from the one tooth to the opposite side wall. A one tooth hole saw does not need any sort of slug ejector.

Sketch it out on paper if you need to to visualize it.

Blast of compressed air through the slots in the holesaw body?

Yes, however a company that is willing to tell a potential customer that their product is not the best for the application tends to profit more from good word of mouth and future business than the lost sale.

I should further qualify that this applies to thin materials. If you have a thick material it is possible that the diagonal measure of the material may be wide enough to get stuck, but this will not be the case with your 1/16" material.

Would it be possible to cut closed cell foam with the hole saw and fill the inner volume to overflowing? It will compress while cutting, but expand and press out the slug when the pressure is gone.

Just a thought.... Paul

Could he mill the hole using something like:

A sideways blast of air to send the slug and swarf flying?

--Winston

I wonder whether a cutter similar to a flat drill bit with the flutes ground with a radius so that the thing cuts only at the center point and the tips of the flutes. similar to the way a wood bit, with its sharp end teeth, does, would work?

Cheers,

John D. Slocomb (jdslocombatgmail)