HE3D printer spacing after first three layers

mtjones

I am hoping someone can help me figure this out.  I have a HE3D 3 color, single extruder printer.  I can not seem to figure out how to get it to print correct.  After the first 3 layers, which lay down nicely, the z spacing is to larger and the print just becomes stringy and not solid.  Any ideas and help would be awesome.  My middle school students have been looking at the printer all year not able to print anything.

Repetier

Slicers have an option for different first layer height, but after 3 layers is odd. First I'd check closely on the generated gcode if Z is always changing only layer height. Also in server you see Z being send - is it really that you you see
0.2
0.4
0.6
1.0 ; big change

or how does it look like? If shown z increases constantly here and you see a bigger gap (how much is it by the way) I would search on firmware side. Try moving Z with gcode
G1 Z0.2
G1 Z0.4
etc.

and see what printer moves in reality.
Check if firmware has features like distortion/bump correction that could be limited to that height and change z unexpectedly. Also check if you have z hops in gcode generation enabled. Some endstops might suddenly trigger preventing to move down again if you check z endstop always. But all this stuff mainly depends on firmware whcih I do not know which one you are using. Just some ideas where it might get wrong.