Need Guidance: Printing Calibration Cubes with Flat Corners

Hi,

I’m printing these cubes in HIPS filament. They come out fine at a higher layer setting (0.2mm) but when I print them at 0.12mm the corners flatten at the bottom. Would appreciate any suggestions. I’m actually getting better prints at a low nozzle temp (220 C) with the bed at 110 C but the corner flattening is stumping me.


This is entirely a temperature issue, and very likely related to your bed temp keeping the bottom of your part too hot/soft. HIPS is a bit, finicky, and you definitely want to print at the lowest nozzle temp you can while still getting good extrusion. Start by tweaking your bed temp. Personally I print the first few layers at 110, then after about .5mm drop the bed temp to 100. Some sources will tell you to go as low as 90-95 so you can experiment with that, but I’ve found I lose adhesion that low. You can also play with your fan speed. I’ve found that with HIPS a range of 40-60% works pretty well. Most importantly though, make any changes to your settings one at a time, and document what’s happening so you know exactly which setting is having what effect.

On a side note, you also seem to be getting a lot of banding from z-wobble. You might check out this post

https://forum.lulzbot.com/t/another-anti-z-wobble-device/2459/1

Thanks for the info, hockey1237. I’ll definitely look into the z-wobble issue as well; I wasn’t sure if the banding was normal for 3D printers (I’m a complete newbie to this).

BTW, do you know if Cura will allow me to set different temps for different layers?

A certain amount of banding is normal, but if you go through the post on that link you’ll see my before and after shots. It’s a pretty noticeable difference.

Cura will let you change the temps based on nozzle height. In full settings mode, under the plugins tab, use the “tweak at Z” plugin. You designate a height for a change to take place and then set the new value for whichever parameters you want changed at that height. You can apply multiple instances of the plugin if you want to make changes at multiple heights.

The banding looks pretty bad on your cube. Its almost like your lead screws bends are completely in phase.

Could try a quarter to half a turn on one lead screw to get them out of phase. You’ll need to turn off the motors or turn off the printer to manually turn the lead screw. Also may need to re-level your bed to account for the slight tilt in the gantry.

Thanks for the info kcchen_00, I did give one of the lead screws a quarter-turn and it seemed to help.

I also printed one of hockey1237’s z-axis wobble parts. It turned out okay but the holes are pretty oval and the seats for the hex nuts are skewed. Is this normal or do I need to tweak some more?


Hockeys? Looks like my one :stuck_out_tongue:

You are heavily over extruding, start with an esteps calibration. .

Sebastian, you are correct, it’s your base part for the z-axis fix. My apologies, I type faster than I think sometimes. :blush:

I will give the e-steps calibration a shot, thanks for the help.