Delta printer - weird second layer behavior

In the finishing stages of building my custom Delta printer. Using repetier firmware and repetier host. I can manually jog everything just fine. X left moves the effector left. X right moves it right. Y back/forward moves it back/forward. Z up/down moves it up/down appropriately. Homing works just fine (homes to axis maxes - UP). I've set the endstop offsets, axis mins. I can even run a G33 command successfully.

I'm not pushing plastic yet, just all dry runs.

1st layer I have the nozzle right about 0.2mm above the build plate and it stays nice and flat throughout travel the entire layer.
After the 1st layer is done, it moves DOWN toward the bed by 0.2mm (my layer height settings) instead of UP 0.2mm making effective Z position 0.0mm instead of 0.4mm.

WAT?!

Edited 4 time(s). Last edit at 03/19/2016 09:45PM by MrBaz.

Have you checked the G code output from your slicer, this problem could be caused by a Z inversion in the slicer software

can you manually enter G code with repetier, try entering G1 Z0, followed by G1 Z0.2.... does the extruder move down?

IF the extruder moves down for the second command then you have the Axes inverted, and probably the jog buttons inverted too.... the two inversion would cancel out so the buttons appear to work, but the g code would have strange behavior...... you may be able to fix this by doing a X axis inversion in your slicer software, but Id check how it affects your compensation etc.

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RepRapPro Mendel 3 Tricolour
RepRapPro Fisher
-Carbon Arms
-Easy adjust Carriage+effector
-axis stiffness mods
HE3D -600 delta
-Duet 0.8.5
-PanelDue
-DC42 Height probe
-RobotDigg metal components
Simplyfy3D
RS Design Spark CAD

Quote
bgkdavis
Have you checked the G code output from your slicer, this problem could be caused by a Z inversion in the slicer software

can you manually enter G code with repetier, try entering G1 Z0, followed by G1 Z0.2.... does the extruder move down?

IF the extruder moves down for the second command then you have the Axes inverted, and probably the jog buttons inverted too.... the two inversion would cancel out so the buttons appear to work, but the g code would have strange behavior...... you may be able to fix this by doing a X axis inversion in your slicer software, but Id check how it affects your compensation etc.

I'll have to check the slicer. Manual code movements are performed perfectly fine. G1 Z0 would take you directly to the build plate. G1 Z5 is 5mm above.

OK, sounds like your slicer, check the G code itself, if you do a search for every Z parameter you should see that they increase as you progress through the file, if they decrease tehn its definately a slicer error, if they increase then its really weird, I don know if there is a G code or M code that can invert an axis in code

---

RepRapPro Mendel 3 Tricolour
RepRapPro Fisher
-Carbon Arms
-Easy adjust Carriage+effector
-axis stiffness mods
HE3D -600 delta
-Duet 0.8.5
-PanelDue
-DC42 Height probe
-RobotDigg metal components
Simplyfy3D
RS Design Spark CAD

Quote
bgkdavis
OK, sounds like your slicer, check the G code itself, if you do a search for every Z parameter you should see that they increase as you progress through the file, if they decrease tehn its definately a slicer error, if they increase then its really weird, I don know if there is a G code or M code that can invert an axis in code

I'm using Slicer that is built into Repetier Host. What would cause this wierd behavior?

you need to check the Gcode output, if there is a slicer fault it will be easy to spot in the Gcode output, post the Gcode file and ill look at it myself

---

RepRapPro Mendel 3 Tricolour
RepRapPro Fisher
-Carbon Arms
-Easy adjust Carriage+effector
-axis stiffness mods
HE3D -600 delta
-Duet 0.8.5
-PanelDue
-DC42 Height probe
-RobotDigg metal components
Simplyfy3D
RS Design Spark CAD

I've attached a gcode snipet below. I cut out a lot of the extraneous code (just X & Y movements) so it is easier to read. You can see that each successive Z movement is in the correct direction. What gives?

; generated by Slic3r 1.2.9 on 2016-03-21 at 14:28:45

; external perimeters extrusion width = 0.40mm
; perimeters extrusion width = 0.67mm
; infill extrusion width = 0.67mm
; solid infill extrusion width = 0.67mm
; top infill extrusion width = 0.67mm

M190 S60 ; set bed temperature
M104 S255 ; set temperature
G28 ; home all axes
G1 Z5 F5000 ; lift nozzle

M109 S255 ; wait for temperature to be reached
G21 ; set units to millimeters
G90 ; use absolute coordinates
M82 ; use absolute distances for extrusion
G92 E0
G1 Z0.600 F12000.000
G1 E-3.00000 F3600.00000
G92 E0
G1 X-17.711 Y31.698 F12000.000
G1 E3.00000 F3600.00000
G1 X13.044 Y-41.697 E17.02905
G1 Z0.800 F12000.000
G1 E14.02905 F3600.00000
G92 E0
G1 X-13.367 Y-47.694 E227.12570
G1 X-14.399 Y-46.662 E227.20212
G1 X-14.731 Y-47.220 E227.23615
G1 X-14.426 Y-47.525 E227.25875
G1 Z1.000 F12000.000
G1 E224.25875 F3600.00000
G92 E0
G1 X-8.815 Y-19.179 F12000.000
G1 E3.00000 F3600.00000
G1 X-4.969 Y-13.853 E3.34320 F3000.000

I messed with some other random calibration settings today (mostly extruder and heater/PID settings). The first layer will lay down just fine, but the second layer doesn't raise at all. This causes significant back pressure on the extruder.

Edited 2 time(s). Last edit at 03/21/2016 06:13PM by MrBaz.

Then its not your slicer

if your G codes work in the correct direction when doing MDI yet work in the opposite direction when running a tape, then I really don't know whats going on... have you tried changing your firmware?

---

RepRapPro Mendel 3 Tricolour
RepRapPro Fisher
-Carbon Arms
-Easy adjust Carriage+effector
-axis stiffness mods
HE3D -600 delta
-Duet 0.8.5
-PanelDue
-DC42 Height probe
-RobotDigg metal components
Simplyfy3D
RS Design Spark CAD

Quote
bgkdavis
Then its not your slicer

if your G codes work in the correct direction when doing MDI yet work in the opposite direction when running a tape, then I really don't know whats going on... have you tried changing your firmware?

I'm running Repetier 0.92.8. I'd like to stick with Repetier. Should I try one version back?

No idea I'm not familiar with Repetier firmware, its just the behavior as you describe is very unusual, just thought it could be a firmware issue...


you could try putting these two lines of code into a program file and see what happens when you run it

G1 Z50 F6000
G1 Z55

---

RepRapPro Mendel 3 Tricolour
RepRapPro Fisher
-Carbon Arms
-Easy adjust Carriage+effector
-axis stiffness mods
HE3D -600 delta
-Duet 0.8.5
-PanelDue
-DC42 Height probe
-RobotDigg metal components
Simplyfy3D
RS Design Spark CAD

Today I made some mechanical adjustments and reaccomplished my standard calibration sequence and guess what? It prints just fine now?!