Bit for flat-bottomed holes?

[glenn bradley]

Removing the center point of a forstner bit will have it wandering all over the place unless the piece is clamped extremely well and the press has zero runout. +1 for the router jig.

I have not found this to be the case using a Freud bit. If the material is held to the drill press table well, the rim does fine in maintaining center. The bit you start with does have to be reasonable quality so that the rim is sharp and well formed. The Fuller bit Mike C describes is a commercial version. I'm assuming your engraver is not able to do the hole.

How much dimple can you stand? Even a 1/16" spur will help in guiding the path. You could grind a "regular" Forstner spur down to that. Since you are doing so many I would think a jig for the drill press would be the efficient way to go. Your DP would need to be capable of consistent depth holes within the tolerance you require, of course.

To the chip clogging issue, bit speed and chip ejection go hand in hand. If you experience clogging, experiment with your bit speed to find the sweet spot.

[Mike Cutler]

Glenn

It was only sheer luck that I remembered they had that bit.
I was at a Woodwerks show many years ago in Springfield Mass, where incidentally I met our Dave Anderson of NH, and Bill Hylton. I bought some large brad point bits to repair some boat railing, from the WL Fuller display, and they had a display showing silvers dollars epoxied into wood, and the bit used to do it.
Why I remembered that I don't know??

[Ted Reischl]

Weird stuff like this is what leads to the sales of CNC machines.

[Jay Nossen]

Actually, forstener bits are guided by the outer edges. One of their best uses is angled hole where the spike won't even contact the work piece until well into the cut.

Johnny,
Until you mentioned it, I was in the "center spike contact is needed" camp. Of course, now I remember that I've used them for many a baluster hole in a stair railings, proving you quite correct.

[Brian Leavitt]

Definitely glad, and appreciative, that you remembered that Fuller bit, Mike. I couldn't find anything like that in my searches.

Glenn, No, the laser will not do a hole like that into Polypropylene. With this type of plastic, it simply melts and flows right back into the lasered area. I don't even like lasering text into this stuff because I think it looks terrible, but my customer likes it so I'm doing it. I am going to use the jig/drill press method here, and I'm passing the cost of the bit right on to my customer.