Z Speed Limit
Posted by kre8
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Z Speed Limit March 19, 2015 11:08AM |
Registered: 9 years ago Posts: 52 |
tl;dr, the question is, how do I set a speed limit on the z axis?
There's the default starting gcode on Slic3r, "G1 Z5 F5000 ; lift nozzle", which results in horrible skipping, because F5000 means hyperdrive. So, I changed it to "G1 Z0.200 F100 ; lift nozzle" and that fixed the problem.
Last night, I was printing something really huge, the biggest thing I've printed. About 2 hours in, the PLA jammed and the voracious extruder cog chewed a piece of the PLA in the process of trying to push it through. So, whatever, no problem, I noticed what had happened about a half hour after it did, killed the print, cut out the damaged PLA, fed some clean filament through, then measured the height of the print and cropped that part off of the front of the gcode so I could continue the print where I left off.
The print was 12.35mm high, so I searched the gcode for "Z12.35" and found the line "G1 Z12.350 F9000.000". Ok, great, crop out everything before that and I can continue the print from where it started having trouble. Maybe you can guess what happened next, the print started, the Z made a horrible grinding cry, skipping and making it nowhere near Z12.35, then the next line of X and Y coordinates brought the print head slamming into the side of my print and knocking it off the bed before I could hit emergency stop.
So, ok, lesson learned, change the F value when you crop your gcode, but even better would be to set a speed limit on the Z axis so that this can't happen.
There's the default starting gcode on Slic3r, "G1 Z5 F5000 ; lift nozzle", which results in horrible skipping, because F5000 means hyperdrive. So, I changed it to "G1 Z0.200 F100 ; lift nozzle" and that fixed the problem.
Last night, I was printing something really huge, the biggest thing I've printed. About 2 hours in, the PLA jammed and the voracious extruder cog chewed a piece of the PLA in the process of trying to push it through. So, whatever, no problem, I noticed what had happened about a half hour after it did, killed the print, cut out the damaged PLA, fed some clean filament through, then measured the height of the print and cropped that part off of the front of the gcode so I could continue the print where I left off.
The print was 12.35mm high, so I searched the gcode for "Z12.35" and found the line "G1 Z12.350 F9000.000". Ok, great, crop out everything before that and I can continue the print from where it started having trouble. Maybe you can guess what happened next, the print started, the Z made a horrible grinding cry, skipping and making it nowhere near Z12.35, then the next line of X and Y coordinates brought the print head slamming into the side of my print and knocking it off the bed before I could hit emergency stop.
So, ok, lesson learned, change the F value when you crop your gcode, but even better would be to set a speed limit on the Z axis so that this can't happen.
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Re: Z Speed Limit March 19, 2015 11:20AM |
Registered: 10 years ago Posts: 541 |
Hi,
You can cap your Z speed in the firmware configuration. There is an entry for maximum axis speeds which specifies them for X, Y, Z and E. It will override anything provided in the G-Code.
Regards,
Neil Darlow
I try to write with consideration for all nationalities. Please let me know if something is unclear.
Printing with Mendel90 from fedora 25 using Cura, FreeCAD, MeshLab, OpenSCAD, Skeinforge and Slic3r tools.
You can cap your Z speed in the firmware configuration. There is an entry for maximum axis speeds which specifies them for X, Y, Z and E. It will override anything provided in the G-Code.
Regards,
Neil Darlow
I try to write with consideration for all nationalities. Please let me know if something is unclear.
Printing with Mendel90 from fedora 25 using Cura, FreeCAD, MeshLab, OpenSCAD, Skeinforge and Slic3r tools.
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Re: Z Speed Limit March 19, 2015 11:29AM |
Registered: 11 years ago Posts: 5,780 |
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