On Wed, 26 Oct 2011 01:06:48 -0500, Richard
wrote:

On 10/26/2011 12:13 AM, Gunner Asch wrote:
Thats hardly a 9 hour part. Unless the guys are doing it with a manual
mill. In fact..on any modern machine..Id be surprised if it took 30
minutes at most.

Just a 4th axis and a pair of custom vise "jaws" and off you go.

Might be better to rough on a lathe, then do the detail work on a mill.
Gunner

I dunno, babe.
Did you catch the taper on the teeth?
Not just the recurved profile, but the Z axis taper?
It looked different facial/distal.

And all the undercutting to remove so much of the weight.

I seriously doubt that was done by hand...

No way was that done by hand. You'd end up with 90% scrap parts.
That's why CNC was invented in the first place: to remove operator
error from the machining process.

And look at the through hole weight saving material removal between
sprockets. They appear to have about a 32nd or a 16th of an inch
radius in the corners. This will require an equally small milling tool
to produce. With such small tools, feed speeds will be very low to
prevent tool breakage. And there are LOTS of them.

I can see where they probably roughed it out and bored the center hole
on a lathe. Makes sense to true it up with a good facing vs. the bore
placement.

The vid said it took 9 hours on the mill. This may be what the sales
rep told the video guys. He may, or may not, have been completely
accurate on the time factor.

Cool part though.
Dave