thumper525
Plastic
- Joined
- Dec 25, 2004
- Location
- Bay Area, CA
I am trying to make sense of the books that give equations for speed (rpm) and table feed to cut aluminum (with a Bridgeport and 1/2" 4 flute endmill).
From what I gather, it is:
rpm = fpm*12 / pi*D
so for a HSS cutter of 0.5", a 750 fpm, that gives an rpm of ~ 5900 ! (this seems too fast)
Feed = ftr * T * rpm
using ftr of 0.016 , 4 flute end mill gives a feed rate of 367 inch/minute
are these correct?
what values are "reasonable"?
(these formulas are from John Walker's Maching Fundamentals)
lastly, if I use a TiN coated end mill, do I HAVE to go faster, or is this "allowed" to go faster?
thanks
From what I gather, it is:
rpm = fpm*12 / pi*D
so for a HSS cutter of 0.5", a 750 fpm, that gives an rpm of ~ 5900 ! (this seems too fast)
Feed = ftr * T * rpm
using ftr of 0.016 , 4 flute end mill gives a feed rate of 367 inch/minute
are these correct?
what values are "reasonable"?
(these formulas are from John Walker's Maching Fundamentals)
lastly, if I use a TiN coated end mill, do I HAVE to go faster, or is this "allowed" to go faster?
thanks