Strange Feedrate GCode Causing Crashes

[finchamp 0]

Hello all,

I have a Geeetech A20M running Marlin, and am using Cura 4.1. I have been using this combination for a couple of weeks now with great results. However, this morning, I switched back from my other printer, made a couple minor setting adjustments (I don't remember specifically; first layer print temp and supports probably), and now I am getting some odd lines in my gcode files. For example:

 

G1 X43.48 Y107.148 E69.47124
G0 F7200 X43.105 Y107.01
G0 X43.272 Y106.556
G1 F3240 E60.47124
G1 F17987547480000 Z0.75
G0 F7200 X43.327 Y106.41 Z0.75
G0 X43.695 Y140.43
;TYPE:WALL-INNER
G1 F17987547480000 Z0.25
G1 F3240 E69.47124
G1 F1200 X42.941 Y140.149 E69.50987
G1 X42.233 Y140.087 E69.544
G1 X41.535 Y140.209 E69.57803

 

You can see there twice in just a few lines, an insanely large G1 F command. I discovered the problem because any time my machine encounters one of these lines, it just freezes completely. No response from the controls, and nothing on serial. If I comment all of them out, it seems to run fine. They occur at almost every change between different portions of the print (as above, just before and after changing to printing an inner wall). Unfortunately, I don't see any settings in my Cura profile that would suggest an issue.

 

I have attached my filament profile if it's any help. Note that I have it set up for 5 extruders; these are virtual extruders, and represent different mixes between the two inputs of the mixing hotend.

 

Any suggestions?

A20M PETG (feedrate problem).curaprofile

Edited June 7, 2019 by finchamp

[gr5 2,071]

Yeah - it turns out that is the speed of light in mm/minute.  It also turns out that Marlin gets confused and doesn't limit it to the max Z speed for you machine.  As it should.  Probably some integer overflow problem.

 

The fix is discussed in this other thread:

 

[finchamp 0]

Thanks so much! Setting "Maximum Z Speed" under the Speed tab on my print profile seems to have solved the problem. So helpful!