forstner drill bit rpm?

[Jeff Monson]

Could someone recemmond a good rpm for a 1/4" forstner bit drilling shelf pin holes in maple plywood so I dont get any tear?

[tod evans]

jeff, the only way i`ve been able to avoid tearout on shelfpin holes is by using a plunge router, a down spiral is probably better but i always use a straight.......02 tod

http://www.sawmillcreek.org/showthread.php?t=27373

[Dale Thompson]

Could someone recemmond a good rpm for a 1/4" forstner bit drilling shelf pin holes in maple plywood so I dont get any tear?
Jeff,
Personally, I would use a good sharp brad point bit instead of a Forstner. :confused: In either case, totally eliminating "tearout" is a bit (no pun intended) of a problem with any kind of plywood. :( With either bit, I would use a piece of scrap to to set my drill press to a depth that JUST allows the point to penetrate the bottom surface. Then turn it over and complete the hole from the other side. 700 RPM would be my choice for the Forsner bit and 1000 RPM for the brad point.

Check out the following:
www.raygirling.com/dpspeed.htm

Good Luck!! :) :)

Dale T.

[Charlie Plesums]

I also use a 1/4 inch solid carbide spiral in a plunge router. I plunge slowly as it enters the ply, then continue at normal speed so it doesn't heat up.

I have a template made from 1/4 inch plywood and use a guide collar on the router, so I can do a whole row of holes in no time.