Won't Print at Start of Build

[bjoernp 0]

Hi, I'm using a Creality CR-10 and Ultimaker Cura and, I have been encountering some print issues.

When I start printing something, it doesn't extrude at the start. I have tried priming it more with up to 10 skirts, but I still have the same problem.
I have also read that you can edit the Z-Coordinate offset, but I don't know how to do that. 

 

Any suggestions?

 

CCR10_45-single-adapter-OohDie.gcode

[GregValiant 1,245]

The gcode file looks fine.  The extrusions are all there and the purge lines are enabled.  The flowrate is set to 100%.

G92 E0 ;Reset Extruder
G1 Z2.0 F3000 ;Move Z Axis up
G1 X10.1 Y20 Z0.28 F5000.0 ;Move to start position
G1 X10.1 Y200.0 Z0.28 F1500.0 E15 ;Draw the first line
G1 X10.4 Y200.0 Z0.28 F5000.0 ;Move to side a little
G1 X10.4 Y20 Z0.28 F1500.0 E30 ;Draw the second line
G92 E0 ;Reset Extruder
G1 Z2.0 F3000 ;Move Z Axis up

             After that it starts to extrude the skirt.

G1 F2700 E0
G1 F1200 X128.068 Y126.979 E0.02002
G1 X128.39 Y126.676 E0.03472

 

If the nozzle is too close to the bed then it won't extrude.  Is the extruder skipping steps?  Do you have an ABL system or are you leveling by hand?

[bjoernp 0]

2 hours ago, GregValiant said:

The gcode file looks fine.  The extrusions are all there and the purge lines are enabled.  The flowrate is set to 100%.

G92 E0 ;Reset Extruder
G1 Z2.0 F3000 ;Move Z Axis up
G1 X10.1 Y20 Z0.28 F5000.0 ;Move to start position
G1 X10.1 Y200.0 Z0.28 F1500.0 E15 ;Draw the first line
G1 X10.4 Y200.0 Z0.28 F5000.0 ;Move to side a little
G1 X10.4 Y20 Z0.28 F1500.0 E30 ;Draw the second line
G92 E0 ;Reset Extruder
G1 Z2.0 F3000 ;Move Z Axis up

             After that it starts to extrude the skirt.

G1 F2700 E0
G1 F1200 X128.068 Y126.979 E0.02002
G1 X128.39 Y126.676 E0.03472

 

If the nozzle is too close to the bed then it won't extrude.  Is the extruder skipping steps?  Do you have an ABL system or are you leveling by hand?

i am leveling by hand could that be the problem?

[gr5 2,167]

If you level too low or too high it won't print at first.  While it's printing the first layer push up and then push down on the print bed.  Usually you can exert enough force to move it the 0.1mm or so you need to do to see a difference.

 

You want it squished quite a bit.  If it's squished so much that it's transparent then it will stick too well so that's a little too much.  If it comes out like a string (rounder - not flattened at all) then it won't stick at all and may just end up all over the nozzle.  Anyway that means the nozzle is too far from the bed.  Perfect high will squish the filament quite a bit but not so much that it's transparent.  Like a pancake.

[GregValiant 1,245]

gr5 is the bed adhesion master, but yes, it can be that you are too tight with your piece of paper.  I use parchment paper as it is only .04mm thick and nothing sticks to it.  When I feel the nozzle "scratch" on the paper, it's just about right.  There are a couple of ways to cheat until you get the feel for it.  One is setting the Initial Layer Height to .28 or .30.  That pretty much insures there will be a gap even if you are tight on the paper.  Remember, you don't need to print a whole model.  If it starts out bad just abort and try again.  It's another thing that calibration cubes are good for.

 

Practice, practice, and then one day you say to yourself "I can't believe I had so much trouble with that".

 

And then the hot end clogs and we can have another little talk.