Questions about tuning before first print

I'm about to attempt a first print in my i2 but need to get a few things figured out first. I'm using marlin FW and Repetier host. I tried doing a phantom print with no filament and it homed properly but then went to a Z of +15mm and started the print from there. I have no idea where to start looking as to why it's doing this. Also I cant get the extruder stepper to move manually to calibrate it - yet it was moving fine during the phantom print. How do I address this?

Thanks,
Ryan

extruder motor usually does not move unless nozzle temp is sensed above 150deg c. I would try to heat up nozzle to at least 170 (when pla flows easily) then fwd extrusion until feedstock flows thru to the nozzle and exits as filament.


check your z height. did you start print with homing z? and did you do a G28 or include this in your gcode?

Edited 1 time(s). Last edit at 12/25/2014 05:17PM by jamesdanielv.

I want to try to extrude 100mm of filament to calibrate the extruder, so I don't want the hot end in place at the time. Is there a way to over-ride the min temp?

For the test I just opened an STL of a basic object I got off thingiverse in Repetier host and sliced with Cura. Then I hit print, so no manual G-code on my end. When I started the print it homed to the proper 0,0,0 position then increased the Z to 15mm to start the print. I can't find anything as to where the 15mm came from unless Cura added it for some reason.

M302 Allow cold extrudes

can you post your gcode. this will help. by post it i mean upload the gcode file. it will help diagnose why z is raising. it more than likely is that no gcode is processed such as when a parser error happens, and that just the beginning code and end code are run. this would mean heat up and run, and then z lift and end.

Edited 2 time(s). Last edit at 12/26/2014 01:46AM by jamesdanielv.

Ok I found the setting in the FW for minimum temp for the extruder so I'm good there. Missed the M302 comment above before changing the setting in the FW but I'll look into that as well. Thanks

Also I found that the slicer after the slicer (cura) in repetier is adding a G1 Z15 after the G28 homing command right at the beginning of the print. I also found where I can change this value. Should this be set to 0 or some nonzero number to define the first layer thickness??

I would need the gcode to know for sure.

Sorry forgot to add gcode, here it is

Huh.. running this code and it looks like the z raises to 15mm until thing are up to temp then goes back to 0 when starting to print though I dont recall it going back to zero when trying the other print. But it appears everything is ok i think. Maybe a DFU problem before.

Edited 1 time(s). Last edit at 12/26/2014 05:52PM by Ryan_M.

yes it looks like it parks the head at 15mm above bed to heat up. the first gcode that extrudes is at z0.3 , which seems as it should

;Generated with Cura_SteamEngine 14.12
; Default start code
G28 ; Home extruder
G1 Z15 F50
M107 ; Turn off fan
G90 ; Absolute positioning
M82 ; Extruder in absolute mode
M190 S50
; Activate all used extruder
M104 T0 S210
G92 E0 ; Reset extruder position
; Wait for all used extruders to reach temperature
M109 T0 S210

Right on that last line it tells your printer to wait for the extruder to hit 210 C before continuing, if you remove that line you should be able to do a dry/cold run