Hey Luca I have a 4 axis vmc. Currently biggest issues is the look ahead when moving 4th axis with other axis as lookahead reverts to just a few blocks. I'm not using your new scurce code on this. I use g94 for 4axis I think. But we tried g93 also. Definitely makes a bit difference But this would be different again I guess
I think I would want to be able to set the dia from gcode then I would link it in with the post processor and make it automatically set from stock dia as you say. Might be a bit of a pain to edit ini file every time. On Wed, 30 Sept 2026, 9:22 pm Luca Toniolo, <[email protected]> wrote: > I'm deciding whether to work on a LinuxCNC feature and would like to > know first whether anyone would actually use it. > > Today, when a rotary axis moves together with X, Y or Z, F applies to > the linear axes only, and a rotary move on its own runs at F in degrees > per minute. On a 4th-axis wrap, where the surface of a cylinder is cut > with X and A, the surface speed therefore doesn't match F. The usual > workaround is inverse time (G93) from the CAM. > > The idea is a reference radius for each rotary axis, set in the INI. For > example, `[AXIS_A] FEED_RADIUS = 25` puts A in the feed calculation as > if it were a length at 25 mm from its centre. A move of A alone at F100 > would then run at 100 mm/min on the surface at that radius, and X with A > would run at F along the combined path. Siemens (FGREF) and Fanuc (a > parameter) do the same. > > Questions: > 1. Would you use this, or does G93 from your CAM already cover it for you? > 2. What machine: 4th-axis wrap, rotary table, something else? > 3. The useful radius is usually the stock radius, which changes per job. > Is a fixed INI value good enough, or would you need to set it from G-code? > > A short "yes, I'd use it", "no" or "G93 is fine" helps. If nobody needs > it, I'll leave it. > > Luca > > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
