Quote
coolduke
and this is the G26 pattern... after this few circles the print suddenly stops and the Z-axis move upwards until I have to reset the printer, or the Z-axis will hit the frame.
Did you ever get to the bottom of this?
I've had this problem on and off for a while. It has plagued me on my Delta since marlin 1.1.6 to Marlin bugfix 1.1.x Dated Jul 14, 2018.
I want to be clear, I'm not blaming marlin firmware or calling it a bug...... I was doing things wrong....
Recently I switched from nozzle as probe electrical contact to a Bltouch. Bltouch is better for my DIY magnetic removable flex bed. With nozzle as probe I had to remove the print surface from bed plate so probe could make electric contact between nozzle and bed. Getting the bltouch setup correctly forced me to revisit delta_radius, printable radius, extruder offsets, ubl mesh inset etc. I believe the crash during G26 is a boundary issue. I think if G26 encounters an undefined mesh point or one that is way outside the range of other points it causes the printhead to move toward z max error.
#define DELTA_AUTO_CALIBRATION
#define DELTA_CALIBRATION_RADIUS 100 // mm
#define DELTA_PRINTABLE_RADIUS 95.0
#define AUTO_BED_LEVELING_UBL
#define MESH_INSET 10 // Mesh inset margin on print area
upload new firmware, load defaults, initialize firmware
M502 ;
M500 ;
M501 ;
delta auto config
M665 B70 ;
G33 A P2 V2 ;
M500 ;
unified bed leveling
G29 P1 V4 ; preform ubl probing
G29 P3 ; fill in missing points
G29 S1; Save UBL mesh points
G29 A ; Activate the UBL System
M500 ; Saves settings to EEPROM
set up z offset
M211 s0 ; softendstops off
Set zoffset
M211 s1 ; softendstops off
G33 P1 ; let delta config use new z offset
M500 ;
Fine tune mesh
G28
G26 B60 H205 F1.75 L0.2 S0.4 P2 Q7 ;
At this point the printer prints the mesh. But sometimes it would crash during printing the mesh g26. But always near edge of print bed. Usually same spot too. I got use to being ready to pull the plug or hit reset button.
Two things I do differently from above that I think have solved the issue, time will tell.
1. I didnt realize that you need to do G29 P3 repeatedly until all mesh points are filled. So in the past I had undefined mesh points, because I would only run G29 P3 once.
Also G29 P3 is an auto fill command. It was choosing a few auto values that were very far away from the other points probe found. 90-95 percent of the points G29 P3 chose were ok. But 1 or 2 where 2-3.5mm higher than the rest. I was never looking at the mesh G29 P3 auto created. So I didnt know some values were so out of whack from the others. Maybe that huge difference effects G33's logic?
Now I use:
G29 P3 C0.00 R4
I view the mesh G29 T, then goto areas with undefined points and fill them in. Using G29 P3 C0.00 over and over until all points have a value.
2. #define MESH_INSET 10 // Mesh inset margin on print area
For a Delta you need points around the edges of printable radius - using any inset value takes points away from the edge.
so now I use:
#define MESH_INSET 0 // Mesh inset margin on print area.
Those 2 changes are the ones I think solved print head moving toward z max while doing G26. (I never knew G26 printed half and quarter circles, in the past I didnt have enough edge points)
Maybe G26, needs more sanity checks. For noob users.