Chamfering holes...Ball nose or?

[Ryan_in_AZ]

I am going to be doing some light aluminum milling with a router table. I just need to chamfer some holes and want to know what the best approach to it would be.

I know I can do it with a ball end and adjust the stepover and depth-per-pass to small amounts to achieve the results I want. But the machine time would take forever it seems.

I just think the whole process would go much much quicker with a 90 degree v-bit. The issue is I don't know what bit to use. Any help on that would be appreciated.

If it helps, I'm using:
Bosch Colt router
Precision 1/8 and 1/4 inch collets

[azmachining]

countersink

[azmachining]

Ryan you need anything milled, turned, bent, sheared, rolled, welded-TIG,MIG,arc we're in the valley. Just let me know.

[Ryan_in_AZ]

Ryan you need anything milled, turned, bent, sheared, rolled, welded-TIG,MIG,arc we're in the valley. Just let me know.

Thanks. I'm in Yuma.

The holes are actually slots so I need to do a bit more than just countersinking. I have the files all done, just need an appropriate bit to do the work and to know what to tell my software I'm using.

[Caprirs]

Depending on how much bevel you want, the common method is to use a 90* spot drill. With a spot drill of 1/8"-1/4" diameter, program the center of the tool .025" away from the edge and about .025" deep. This will give a bevel of about .005". If you're using CAM, tell the software it's a .050" diameter tool and program .025" deep.

For example, to chamfer a .500" hole located at X0. Y0. using a 90* spot drill:

G0 X.225 Y0. (Starts at 3 o'clock)
Z.025 (rapid plane)
G1 Z-.025 F... (Plunge)
G3 I-.225
G0 Z.025 (Retract)

Adjust depth and .025" offset to control the size of the chamfer.

[Bob La Londe]

The fastest way to do it would be with a chamfer mill, v-point end mill, spot drill of appropriate angle, etc. Some countersinks might work, but a lot of the cheap ones aren't sharp enough for aluminum. Even a sharp router bit will work on aluminum with appropriate speeds and feeds. I prefer carbide end mills for most things with aluminum, but when I need to do something and I can't wait to order in a decent end mill for the job (nobody I know in Yuma has much of a selection of mills), I'll sometimes look to see if one of the box stores has an over priced carbide router bit that will do the job.

Also, in Yuma.

I do almost exclusively aluminum work on my small mills, and wood and aluminum on my router table. I'm on the edge of getting my big mill going though, and I'll do slower spindle heavy work with that. I'm also starting a retrofit on a mini lathe. Well, I ordered some parts for it, but the more I think about it the more I am thinking a ground up build would be better.