Question about firmware values using mm/min

fcwilt

Hi,

I have a question whose answer may have it's roots in history.

The DWC displays things like movement speeds in mm/sec.

Articles that discuss "tweaking" a printers performance tend to talk about speeds in mm/sec.

Yet the firmware in certain places uses mm/min.

Why the different units? It there any technical reason? If mm/sec COULD have been used might a future version allow for that?

Thanks much.

Frederick

dc42

GCode was originally invented for CNC machines. They work at much lower speeds than 3D printers, so inches/min or mm/min was a sensible unit.

RepRapFirmware is consistent in that all speeds used in GCodes are in mm/min, except for one that was added for compatibility with Marlin. Marlin is less consistent: some speeds are in mm/min, others are in mm/sec.

fcwilt

@dc42 said in Question about firmware values using mm/min:

GCode was originally invented for CNC machines. They work at much lower speeds than 3D printers, so inches/min or mm/min was a sensible unit.

RepRapFirmware is consistent in that all speeds used in GCodes are in mm/min, except for one that was added for compatibility with Marlin. Marlin is less consistent: some speeds are in mm/min, others are in mm/sec.

Thanks for the information. I figured history was involved.

If you are ever sitting around one day with nothing to do how about adding a new command to switch the units in the config files from mm/min to mm/sec to be consistent with information displayed on the DWC and such.

Frederick

Phaedrux

I think it makes more sense to display mm/s in the DWC because slicers generally use mm/s for their speed settings.

fcwilt

@phaedrux said in Question about firmware values using mm/min:

I think it makes more sense to display mm/s in the DWC because slicers generally use mm/s for their speed settings.

I agree and thus it makes more sense, to me, to use the same, familiar units in configuration files.

I understand the history but if the only reason for using mm/min is the history I think a change could be considered, even if as an option, as I suggested.

Frederick