Disperate feed rates

I have a rotating axis (A) and an linear axis (X). The A has a max feed rate of 3600 degrees/min and the X 18 inches/min but when I'm machining I only want the x feed no more than 10 ipm. If I use F10 the A slows to a crawl but F1800 permits X to attain the max 18 ipm. The only solution I see is to limit X to 10 ipm in stepconf but I wonder if I'm missing something. Doing this, of course, slows down my G0 moves.

Thanks for any suggestions

You might want to look here...
www.linuxcnc.org/docview/html/gcode_main.html#sub:G93,-G94:-Set
and
www.linuxcnc.org/docview/html/common_mac...r.html#sub:Feed-Rate

Rick G

Mea culpa

radek is right. My error was in programming an A only move after the combined move so F10 was still in effect and limited the A axis to 10 degrees/min. I just couldn;t see for looking.



Thanks or the help.

There is still a problem but a simple if not elegant solution. I'm driving my position by some transcendental functions and sometimes there is a series of lines where the x axis doesn't change. This causes the A axis to feed at the slower rate as specified in the manual. I wish the specs said that if there is a x position specified then feed would be based on the x axis but they say instead that if x doesn't change feed is based on the A axis. My solution is to put a 0.0001 inch wobble in the x axis that is not noticeable in the product but causes the interpreter to think x has changed.

From one of John's post...

www.linuxcnc.org/docview/html/common_mac...r.html#sub:Feed-Rate

1. If any of XYZ are moving, F is in units per minute in the XYZ cartesian system, and all other axes (UVWABC) move so as to start and stop in coordinated fashion
2. Otherwise, if any of UVW are moving, F is in units per minute in the UVW cartesian system, and all other axes (ABC) move so as to start and stop in coordinated fashion
3. Otherwise, the move is pure rotary motion and the F word is in rotary units in the ABC “pseudo-cartesian” system.

So could you set the proper rotary feed rate for the rotary only moves and revert to the proper linear feed rate for combined moves?

Rick G