Search:

Not to derail the thread, but I had a similar issue this weekend - 0.75" through holes in 6061, drilled 0.1590", tapping 10-32 with spiral point tap and Procunier head.

I used the recommended M871...

The part is 2"x4"x0.5" thick, held in a vice (on parallels) with about .125 of grip.

The chatter is also present when I take cuts on a 1" thick test piece.

Ray L.-

Thanks - I'm using HSMExpress and mainly using the adaptive toolpaths, so the limiting should be in place.

I'd arrived at increasing the chip load as a possible solution, but your...

I seem to be holding decent tolerences (around 0.001), its just the chatter and surface finish that was maddenning.

The biggest shock to me was moving from coated HSS to uncoated carbide, keeping...

G59, Tony978-

Thanks. The tool stickout is only about .75" (flute length) so I don't think that is excessive. It looks like I need to try to increase the feed rate and see what that gives me.
...

G59 - pretty cheap, uncoated, no-brand 'solid carbide' for around $8 ea. AllIndustrial via eBay.

The material is 6061-T6 aluminum.

I had thought (incorrectly?) that anything would be better...

I am new to using a Tormach and have recently purchased some 1/4", 2-flute, carbide end mills to use instead of the cheap HSS bits at the Techshop. Previously, I was able to run the HSS at 4000 rpm,...