2654
« on: December 16, 2005, 05:11:31 AM »
Hi Keith
the a axis indexer should be set up so that one full rev of the indexer is 360 degrees (0 to 359) that way all calculations for movement are decimal degrees.
what you have to watch out for is feed matching (G01) if you want to mill a slot at 45 degrees round a 1 " bar over a 90 degrees length round the bar the command G01 X19.95 A90. F100. would give a slot at 45 deg on a 1" dia bar.
WHAT! I here you cry.
If you take the top and bottom off a been can, then cut the tube down the length, opened it up and rolled it out flat the rectangle you are left with is the circumference of that dia can (less the cut width).
If you then draw a line on that rectangle at 45 degrees from the cut edge to 1/4 of the way up the length that is what you would get on a round bar of that diameter.
so a formula
bar dia 1"
45 degree slot running from right to left over 90 degrees
1"*25.4*PI = 1*25.4*3.1415 = 79.7941
90 degrees is 1/4 rotation so 90/360 = .25
79.7941*.25 = 19.9485
So the X axis movement is 19.94mm
G00 X0 A0
Z1.
G01 Z-.2 F50.
G01 X-19.94 A90.
G00 Z25.
If the feeds are not matched then the slot will not be at 45 degrees.
I hope this helps
Graham.