3.5.0-rc.4 Z (print head) crashes into bed at end of print

gloomyandy

@Nate-Nygren I think we would need to see your homex.g file as well.

Nate.Nygren

@gloomyandy
Using the Home X button in DWC works fine, no Z crash.

homex.g

; homex.g
; called to home the X axis
;
; generated by RepRapFirmware Configuration Tool v3.5.0-rc.3+2 on Fri Apr 05 2024 23:17:10 GMT-0500 (Central Daylight Time)

; lift Z
G91 ; relative positioning
G1 H2 Z2 ; move Z relative to current position to avoid dragging nozzle over the bed
G90 ; absolute positioning

; home X
var maxTravel = move.axes[0].max - move.axes[0].min + 5 ; calculate how far X can travel plus 5mm
G1 H1 X{-var.maxTravel} F6000 ; coarse home in the -X direction
G1 H2 X5 F6000 ; move back 5mm
G1 H1 X{-var.maxTravel} F3000 ; fine home in the -X direction
G1 H2 Z-2 F6000 ; lower Z again

gloomyandy

@Nate-Nygren I'm not sure you correctly understand what the H2 parameter to a move is doing. So for instance it looks like you expect that the final G1 H2 Z-2 move to be a relative move, it will not be. Instead it will be moving Z to -2 (which is probably what is causing your crash). So for many of those moves you need to be setting relative mode before you make them. I'd also suggest removing the H2 parameter from most of those moves, it probably is not needed.

Nate.Nygren

@gloomyandy I agree the H2 doesn't need to be there, but this homex.g file was generated by the RepRapFirmware Config tool, and like I mentioned above it works fine if it's called by the Home X button in DWC, so I didn't edit them out.

gloomyandy

@gloomyandy Well something is wrong with it, look at the first Z move it is relative, but the second one isn't. I'm pretty sure that last z move is what is causing your problem. Why not try making the changes and see if it fixes the problem?

Nate.Nygren

@gloomyandy I'm already on it I commented out the last G1 move in the homex.g file, which isn't really necessary anyway, and am heating up for a quick print test.

Nate.Nygren

@gloomyandy Bingo, commenting out the last G1 move was the key. Thank!

gloomyandy

@Nate-Nygren You might be better off moving the G90 to the end of the file, it looks to me like all of those moves are intended to be relative moves.

Nate.Nygren

@gloomyandy I'll suggest that in the report to the ConfigTool repo.

chrishamm

@Nate-Nygren Thanks for reporting this, I just fixed it in the configtool.