Countersink router bits

[waynec]

I've read some of the threads about using drills, routers, etc. for countersinking and drilling. Seems the concensus is to mount a drill and use a countersink designed for drills.

But on my single axis machine, that seems like a bunch of labor to drill a few dozen holes, then remount the router to cut profiles.

What would work best for me is to find a router bit that will countersink and drill even partway thru the 3/4" pine.

Anybody know of a source for countersinks designed for router speeds? Even a stepped bit would work.

I'm trying to drill countersinked holes for Adirondack chairs.

Wayne from White Salmon

[richards]

I use a 90-degree V-bit for most countersinking. As far as I know, 82-degrees is 'standard'; however, after searching the web, I've begun to wonder if there is a 'standard' countersink angle.

When I've had to countersink speciality computer related screws that didn't fit the 90-degree angle of a V-bit, I've still used the 90-degree V-bit to cut a shallow hole that was used as a guide when hand-drilling the countersinks or drilling the countersinks with a drill press.

Mike

[rhfurniture]

Why countersink?
I use a 4mm routerbit, round pocket 8mm dia x 2mm deep and bore in the middle for 4mm (No 6) screws. Comes up real neat and in pine the screw will form its own seating.

R.

[mikejohn]

How deep do you go with the 4mm?
How long would it take to bore, say 20 holes with countersink?
..........Mike

[rhfurniture]

As deep as the bit will go. The Trend (UK) spiral I use is rated at 16mm, but will add a mm or two without grief (bore the pocket first). Otherwise I use the 5mm window trade bit (single flute spiral HSS)I use for morticing which goes up to 35mm.
Speed? cuts them faster than I can work them out..
(2 networked computers a must have in my book)
R.

[waynec]

RH, that's a good suggestion. I'll try it with an 1/8" bit- the pine is plenty soft enough for the screws to self seat. I also am concerned that the large dia. hole will be accurate enough for the plug to fit snug. Probably not a problem, but I think of this sort of thing.

I also found a plunge and roundover bit that has the right dimensions from MCLS. It's 3/8" large diameter, with 1/8" small diameter. Same as a countersink. But its designed for router speeds, so I dont think it will burn in pine. it has a radiused shoulder, but again the pine is soft enough that the screw should just make its own fit.

Thanks. Tomorrow morning I'll give it a try.

Wayne from White Salmon