On Tue, 28 Dec 2010 00:04:37 -0600, Ignoramus7943
wrote:

Karl, I wanted to ask a question about manufacturing methods for the
Ar-15 receiver.

Look at this:

http://www.cncguns.com/projects/ar15lower.html

He had to reclamp his piece numerous times to make it on a CNC mill. I
wonder, how much of that is due to lack of the 4th axis.

My feeling on this is that with a suitable 4th axis, this receiver could be
done in 2-3 reclampings, or perhaps even one. With a 4th axis, clamp
once, and then turn various sides towards the spindle to be machined.

Am I making any sense?

i
I had not seen this site, thanks.

You have a valid point, but you lose so much rigidity that your
machining speeds would be killed.

Most parts are manufactured with a real eye on fixturing. That is ways
to quickly remount the part for the next operation. With a good
fixture design, you can go from one op to the next in a few seconds.
















I had not seen this website, thanks for the link.