Week 5: 3D Scanning and Printing¶
group assignment: • test the design rules for your 3D printer(s)
For our group assignment, we each chose found an online design to test each of our printers’ capabilities.
FAB Lab NODA’s Printers: We have 3 different Prusa brand printers. 2 Prusa MINIs (equipped with 0.4mm and 0.6mm nozzles) and 1 Prusa i3 MK3S+ (equipped with 0.4mm, 0.6mm, and 0.8mm nozzles)
Micro All-in-One (Castor)¶
Testing the printers¶
I went on to Thingiverse and chose the MICRO All In One 3D printer test as a print test. I printed the same model in the same size with 90% infill no supports, and smei-transparent PETG+ in different colors.
Each color represents was printed using a different printer and nozzle size.
| Color | Printer | Nozzle Size |
|---|---|---|
| RED | Original Prusa MINI | .04 Nozzle |
| GREEN | Original Prusa MINI | .06 Nozzle |
| BLUE | Original Prusa i3 MK3S | .08 Nozzle |
The creator of the test print has a hany guide and website to help you understand how the test works. Each part cirled represents a different aespect that the print is testing. Depending on how the print fails, it can show you what setting you may need to change such as speed, temerature, and fan speed.
The yellow rectangle is the stringing test. stringing is the thin, hair-like strands left behind when the nozzle moves from one point to another.
Red has some minor stringing.
Green has major stringing.
Blue has even more tringing than green.
The green circle is testing how well your machine can print out a sharp spike.
Red did very well. Both spikes are sharp.
Green did okay. Both spike are both there but they are not sharp. Lots of stringing and globbing near the tips.
Blue had major stringing issues, but less globbing issues than green.
The black circles represent the overhang test. The overhang is tested from 10° to 80°, in 5 degreee increments.
Red starts to fail at 75°.
Green starts to fail at 70°.
Blue starts to fail slightly at 20° and even more at 45°.
The purple circle is the bridging test. The bridging test is about learning how far your printer can make a line from one point to another without support. This tests bridge lengthes of 2mm, 5mm, 10mm, 15mm, 29mm, and 25mm.
Red did fine aide from the stringing. the 25mm bridge had a burn on it and there was a glob between the 25mm and 20mm bridge.
Green also had stringing issues, but all the bridges worked perfectly.
Blue had major stringing issues to the point that the srings created a small wall. Most bridges were fine, but the 20mm and 25mm bridges drooped a little in the middle.
Testing Summary¶
| Red | Green | Blue | |
|---|---|---|---|
| Stringing Test | Fail | Fail | Fail |
| Sharp Corners Test | Pass | Fail | Fail |
| Overhang Test | Fails at 75° | Fails at 70° | Fails at 20° |
| Bridging Test | Fails at 20mm | Pass | Fails at 20mm |
Clearance Tolerance Test (angela)¶
All three prints of the tolerance test design.
For my part in the group assignment, I ran three tests of the same model using this online clearance tolerance test design by 3DMakerNoob on printables.com. This is a helpful tool for creating designs with moving parts (i.e. they have some type of small gap) so they don’t fuse together. This website allows you to open the file directly into the PrusaSlicer software.
Each of these prints had 15% infill settings and used Generic PETG as the filament. The printer settings for the 0.8mm Prusa i3 MK3S+ (printed in blue) was 0.4 mm QUALITY; for the 0.6mm Prusa MINI was 0.25mm STRUCTURAL; for the 0.4mm Prusa MINI was 0.15mm QUALITY. Within the software, it was useful to experiment with slicing at different print settings to see if higher quality would be worth the additional time or to see if it made much of a difference in time at all.
| Test | Blue (0.8mm) | Green (0.6mm) | Pink (0.4mm) |
|---|---|---|---|
| Print Speed | Fastest | Medium | Slowest |
| Stringing Test | lots of stringiness | less | even less |
| Numbering Test | unreadable | slightly defined, practically unreadable | all numbers readable |
| Clearance Test | Failed at 0.10mm | Passed | Failed at 0.10mm |
Lessons Learned and Troubleshooting
- Nozzle Size: The 0.4mm nozzle provided the highest detail, whereas the 0.8mm nozzle provided the fastest speed
- Clearance Tolerance: The sweet spot for the blue print was within the 0.20mm to 0.25 mm clearance range (of course, depends on function of print). Any bigger, the embedded balls would too easily fall out and any smaller they were either fused or take too much effort to move. The sweet spot for the green was right at 0.15mm - 0.20 mm. The sweet spot for the pink was also at 0.15mm - 0.20 mm. But overall the balls did much better with not falling out when you shake the object even at the larger clearnances.
- Quick Tips: Use Shift+A in Prusa Slicer to center objects on the bed. Keep the default G-code file names provided by PrusaSlicer as they keep useful data about print settings used. The print bed can get up to 100 degrees Celcius! It’s important to be careful.
As a final note on these test prints, we did have to tend to a couple issues with the printer “gooping” and thus making our prints unworkable. When this started happening with one of my prints, I cancelled the job and Will showed me how to use the Live Adjust Z feature while re-running the print to ensure the nozzle is set at good distance from the bed so it doesn’t goop.
It dried up a bit but you can see where the print started to goop and mess with the design