Bottom of parts squished / Z travel compressed near bottom? (Ender 3)

Ken_Johnston
Wed, 13 Mar 2019 18:43:35 +0000
3D Printing

Hi,

I just got an Ender 3. Overall it’s been great but I’m seeing something weird that I haven’t seen posted online.

It appears that the Z- is traveling too little, only at the bottom of the part. The first several layers are squished and appear very “wet” when building, as if the machine is over-extruding. Parts bulge out (elephant feet) and features are lost.

But then at about 0.5-1.0mm, it sorts out and prints fine. I’ve played with temp / bed temp, bed height and leveling, etc, and the very first layer looks great. So I don’t think it’s a Z home issue. If I were to lower the bed to try and address this, the filament wouldn’t even touch it.

I put a ruler up against the extruder, and when I jog from Z 0.0mm to 1.0mm, sure enough it moves more like ~0.6mm. If I keep jogging in 1mm increments, those look well calibrated.

See pic of a 20mm XYZ calibration cube. Using calipers, the Z height is ~19.4mm (X & Y are fine). And from part bottom to the bottom of the “X” measures ~3.0mm whereas from the model, it should be 3.6mm.

For the print shown I used Cura with the default “draft - 0.2mm layer height” profile. But I’ve tried tons of other profiles and Simplify3d as well…

Any ideas on what might be going on here? Thanks! Ken

7 posts - 4 participants