Printing the Make Shootout objects

I’ve been trying to print the Make Shootout test objects. I’ve been using Cura for slicing, with the profiles from Lulzbot, 100 micron layer height and 50 mm/sec speed and Shaxon translucent blue filament at 200C.

I’m curious about how to improve results on the following test pieces:

(1) Fine Positive Features has lots of stringing at the tips of the spikes. I’d really like to know how to get rid of this.

(2) Bridging does OK, but not great. Curious as to advice on to how to get really good results.

(3) Robot: 1 hip joint and 2 leg joints fused.

Also curious as to why the Lulzbot profiles have nonstandard default layer heights, like 140 microns, 210 microns. Is it just a reflection of multiples of the minimum 70 micron? Or is there some reason it would print better at 140 than, say, 100 or 150?

In order to better make print quality recommendations, post your model and pictures, showing the areas in questions, and what profile you used. It’ll help us make some recommendations.

Files:


I’ll upload the profile tomorrow, but really it was just as I described. The Lulzbot PLA Cura profile, tweaked with speed at 50 mm/sec, layer height 100 microns, and nozzle temp of 200 deg. Also tried 210 and 190, with similar results.

-Keith


Here’s the profile I was using
TazShootoutProfile.ini (10.9 KB)

The fan can be turned up a bit higher, and retraction can be tweaked a bit- Keep in mind that when you switch from the Cura quick print to the full settings you’ll have to download and load the profile into Cura: https://github.com/alephobjects/print_profiles/tree/master/cura

Try increasing the fan speed a little bit, or drop the temperature down a degree or so.

When you refer to “tweaking” the retraction settings, could you be more specific? I tried increasing the retraction a bit, but it didn’t seem to make a difference.

As to the Fan, the Cura profile has it on at 100%.
Capture.PNG
Perhaps Minimum speed or Cool Head Lift should be changed? Not sure I really understand those options. Or maybe there’s a better fan shroud available?

Have you printed this piece yourself? I’d be curious to see what sort of results others are getting.

WIth the fan blowing at 100% do you feel any air coming out the back of the fan? If so drop the fan speed 15% or so and see how that helps with reducing the back pressure.

slicing profile recommendations:

layer_height = .10 This is rather low for bridging. Try 0.14 or 0.21
print_temperature = 210 Try 190 ( I know you tried this already, but the cooler it is the better bridging you’ll get…)
retraction_amount = 1.5 try 1.7 then 2.0
cool_min_layer_time = 15 try 10

You don’t need these lines in the start.gcode:
G1 Z15.0 F{travel_speed} ;move the platform down 15mm
G92 E0 ;zero the extruded length
G1 F200 E0 ;extrude 3mm of feed stock