[eloeffler]

im working in polar interpolation on the sub side of a star sr-20 and weve been trying to figure out the correct way to find the feed rate while in polar....
i gues in other words what im asking is,
how do you convert inches/mm per minute into degrees per inch/mm..... or would it be degrees per minute....

i know the basic information that ill need will probably include the obvious, plus im assuming how far you are from center of the work pc would come into affect... anything past that im not too sure....

if theres anyone out there who would be willing to explain it to me that would be great.
thanks in advance!

[Al_The_Man]

I am not a programmer, but maybe you could implement the principle used in SFM surface feet/minute as calculated when turning?
RPM Vs Dia etc.
But isn't this a lathe anyway?
Al.

[eloeffler]

this is a swiss turn screw machine, im milling on the sub side with a high speed spindle at about 14 thousand rpms, using a 4 flute .055 mill. my smm(surface meteres per minute) is around 200mm(my machines in metric) milling in polar interpolation, this is no longer a linear move, wich to me means i need to transform my meters per minute into degrees per minute via the sub spindles rotation, or "c" axis. i am new to this forum, is there a different place i should be posting this? thanks for the help al_the_man

[holbieone]

i don't know your machine so i guessing here ,

use inverse time and you would need to program a radius for the axis driving the part then figure out the arc length to get your time

[eloeffler]

is there a good equation for using inverse time? aside from having that im with you on this idea. thanks for the help

[holbieone]

this mite help http://www.cnczone.com/forums/haas_m..._4th_axis.html