UMO Overhang Problems

[dylanweber 0]

I've been using my printer for some months now, and I usually refrain from printing prints that have overhang. Since I built the machine, overhang has been a problem for me. Most of the time, hanging plastic curls up. Here are a few examples of prints that have poor overhang and their print settings.

Print One: http://www.thingiverse.com/thing:202774

Print settings:

Speed: 50 mm/s

Print temp: 205 C

Layer Height: 0.1 mm

Shell thickness: 1.2 mm

Bottom/Top Thickness 1.2 mm

Fill density: 20%

Retraction speed: 40 mm/s

Retraction distance: 3 mm

Travel speed: 150 mm/s

Print two: http://www.thingiverse.com/thing:8757

Print settings are same as above except:

Speed: 35 mm/s

Print temp: 195 C

The average room temperature during these prints was 75 F. Do you think the room temp would affect the print quality and/or rising of the plastic while hanging? What improvements could I make? I already have this fan shroud installed as a replacement to the stock one.

 

[dylanweber 0]

I made a mistake. Can a mod move this topic to troubleshooting?

 

[aviphysics 9]

On the pyramid, I would wonder if you had some problems with slipping during retraction. It looks like there is some serious under extrusion going on there. Also looks like there might be some under extrusion on the top layer of the base of the pyramid.

 

[nick-foley 5]

Yeah, in general, it looks like you are having some sort of extrusion related problem. Even your walls without overhangs are very uneven. Maybe there is a clog developing in your nozzle? Or maybe your extruder isn't set correctly. Or maybe something is up with your Z stage.

I would try to solve that first before fixing your overhang problem, if it even still exists when extrusion is straightened out. Improving overhangs is simple - if everything else is working fine, just add more cooling to your printer, in the form of a crossflow fan or even a desk fan.

Sorting out the extrusion problem will require more troubleshooting, but problems with extrusion will prevent you from addressing anything else about the printer until they are solved first.