[ List Subjects ][ Post Message ]
Subject: How to figure 4th axis feedrates?
[ View Followups ][ Post Followup ]
Date: 06/06/02 at 8:15 PM
Posted by: Sam
I run a Cincinnati Milacron Arrow vmc1000 that I finally convinced them to install a 4th axis on. Which is great. Some really interesting work has been coming through since we got it. The thing is is that no one knows how to accurately figure the feed rates for the indexer. Its just trial and error. For instance, on one part I'm milling various cam slots around a 10" ring. If I make an index only move, I eventually get the feedrate about right. However if the next move is similar, but with a move in the x direction as well, the feedrate is completely different. It seems like the proportion of index move to x move makes the feed change. Say I index 45 deg. and only move .05" in x, versus index 10 deg. and move 1" in x. I end up with completely different feedrates. The only solid fact I've been able to come up with is that always putting an x move, even if there isn't one, with an index move brings the feedrates a little closer. (Still way too far off though):
X0A20.F? (never only A20., always X0A20.)
X-.5F20. (here I can figure F accurately using sfpm)
Troyke and Cinncinatti websites are both completely worthless. Anybody? Parameters?? Constant surface speed formulas??? A website recommendation????
Post a Follow-up: