Tagged: Marlin Z feedrate steps_per_unit
- January 23, 2016 at 10:48 am #6261
my MPCNC is running ! Thanks, Vicious1, for the great project!
I realized, the travel speed is lower than the feed rate. Feed rate was set via Estlcam to 15mm/s. I created a gcode file with Estlcam and ran it from SD-Card via LCD.
Loocking in Configuration.h from Marlin I found XY_TRAVEL_SPEED = 8000mm/min (133mm/s) but my travel speed is definitely much lower!
I don’t yet have endstops and tried the set home option in the LCD menu, but it does not work. After set_home_position somwhere and choosing goto_home_position the MPCNC would move until reaching the mechanical end. It’s not important and not really a problem.January 23, 2016 at 3:58 pm #6278
I believe that the XY_TRAVEL_SPEED setting in the Configuration.h file is the maximum speed allowed, not necessarily the common travel speed. The movement speed would be defined within your post processing.
As for the homing issue, that is correct. The homing function, G28 is homing in the -‘ve direction until it hits an endstop. You are probably looking to just go to your programmed 0,0 so try : G0 X0 Y0January 24, 2016 at 2:10 am #6293
thank you. I produced the gcode with Estlcam (no further post processing) and printed direct form SD-card via smart lcd. I can find the feed speed values produced by Estlcam in the gcode (Fxxx commands) but only G0 commands for travel and no speed value setting for G0. So I assume the travel speed value must be set somewhere in Marlin. If it is not XY_TRAVEL_SPEED I have to look further.January 24, 2016 at 8:34 am #6294
On the LCD unit, you can change some of the acceleration and jerk settings which is easier than making edits and reflashing the firmware. More likely than not, you will never hit your max speed, so the acceleration and jerk settings have more influence on the overall speed when making short movements.February 19, 2016 at 7:47 am #7875
Z-feedrate and a hint to the IE-Builders:
To get a maximum of 40000 steps per second with a DEFAULT_AXIS_STEPS_PER_UNIT of 5120 for the 8mm threaded rod, I think Z-feedrate has to be limited to 7.8mm/s instead of 8.7mm/s for the 5/16 threaded rod. (40000/5120=7.8125)
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