6. 3D Scanning and printing¶
Browse through the NuEval Handbook to review the evaluation criteria.¶
Group Assignment¶
The general group assignment for 3D printing was to print different design rules and understand cases in which to use the rules to your benefit.
For our group assignment, we are printing the examples files from the lecture
Anna¶
Prusa MK4S¶
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|---|---|
| Prusa Mark 4 | 0.10 mm layer thickness angle test |
Specs
Without Support Tests¶
Below a few different files were tested in the mk4 Prusa with 15% infill. First the green/blue filament was 0.10 mm layer lines. This print took 4 hour and 15 minutes. The next print, the white filament, with the same files for test was printed with 0.20 mm layer thickness. This print only took 2 hours to print. Below the performance with the different setting will be discussed and also compared.
Angle Test
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|------------------------|------------------------|
|0.20 mm layer thickness angle test|0.10 mm layer thickness angle test|
Overhang
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|------------------------|------------------------|
|0.20 mm layer thickness overhang test|0.10 mm layer thickness overhang test|
Bridging
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|------------------------|------------------------|
|0.20 mm layer thickness bridging test| side view of 0.10 mm bridging test|
Wall Thickness
Surface Finish
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|------------------------|------------------------|
|0.20 mm layer thickness bridging test| side view of 0.10 mm bridging test|
Overall Performance
Albert¶
Prusa i3 MK3S+¶
Prints with support¶
My tests are to do the sample prints for the overhang and clearance tests with support. For these, I took the STL test files on the scanning and printing notes page.
I downloaded these STLs, loaded them into PrusaSlicer. Within a project in PrusaSlicer, use the “Import” option to read in the STL files. Since these are small prints, both the overhang and clearance files were loaded at the same time.
Two STL test files loaded
To add support, click the “Print Settings” tab, and then go to the “Support Material” area. In there, click the “Generate Support Material” checkbox.
Print settings page with support options
Then, back on the plater page, use the “Slice Now” option at the bottom right. This generates slices needed for printing, while also adding the support. The default infill setting of 15% was used.
Slices made, ready for Gcode export
The previous was done with me working on my home computer. I did the same steps in the lab, as they are very quick. The lab computer has default settings for the printers. I am printing with PLA at 0.2mm layer thickness.
Sliced models ready for printing
The Gcode was exported onto the memory card for the printer, and then this card was inserted into the printer.
A blue PLA filament reel was loaded into the printer, and the file loaded for printing. The printer bed needed to be heated to the correct temperature for PLA, which is nicely and automatically handled by the printer. Then the printer made the prints.
Prints made on the Prusa MK3S+
When completed, the supports needed to be removed. Those were fairly simple to remove with pliers, and a small screwdriver helped to pry off the last little bits.
Prints with support removed
The final prints were available for examination.
Final overhang and clearance prints
Overhang
For the overhang print (with supports), it printed very well with no sagging.
Clearance
The clearance test results in squares along a rod. Each square has a circle, with different gap clearances. These gaps go from 0.1mm to 1mm, with steps of 0.1mm. After removing the support material, all the squares down to 0.3mm clearance moved freely. The largest ones, especially the 1mm clearance, could move quite a bit, while the 0.3mm had a relatively fit. Therefore, when wanting to print a part with moving pieces, the clearance should be at least 0.3mm.
Comparison to prints without support¶
As Anna and I split work on the Prusa printers, she did the test prints without support. We reviewed her prints together. Notably, the angle test was a comparison to the overhang print. In the angle test, the 0 and 10 degree versions were very rough. The overhand and bridging tests also had a small amount of sagging.
Anna also ran the wall thickness and surface finish tests which we reviewed together. Her images are seen above.
Evert¶
Bambu Lab A1¶
Here we wil discuse the performance of Bambu A1 on this printer there was few test print done all with 0,2mm layer thickness each part was printet seperatly.
In this test i used Filamentfrom:
- Prima Value
- printing temperature 200-230°C (210)
- bed temperature 45 -60°C (60)
- Green color
Angle Test
In this test i testet how much angle the printer could handle. we did print out test object that had from 90 degre angle down to 0 degre, 0 being thi biggest angle. It was very clear result from this test 20-90 degree angle was printed very good and whit no extra marks on the print, 10 degre angle had little bit rough edge, 0 degre edge was also little bit rough like 10 but still not so bad.
Overhang
In this test we printet ten 90°angle were overhang was from 1mm - 10mm, this was challenge for the bambu were the overhang was 2mm it startet to deform and were it was 6mm it was already that bad that it was not axeptable. i would say that if your printing overhang that ar 2mm or more you need support.
Bridging
In this test we printet 10 bridge with 2mm -20mm between the feets and then printed between the feets, the results is clear this was not any challenge for the bambu it printed with 100% quality all the way.
Magnus¶
Prusa Mini+¶
I’m printing the test pieces on my Prusa Mini+ I’ve had since 2020. I have a 0.6mm nozzle installed at the moment and I decided print all the parts together except for the bridging test. I’ll add notes underneath each images explaining issues and how to address them.
Prusa Mini Specs & Notes¶
- Build volume is 180 x 180 x 180 mm.
- Maximum nozzle temp is 280°C
- Maximum heat bed temp is 100°C
- It uses a Bowden system instead of Direct Extrusion like in the MK3 and MK4.
- Mine is equipped with a 0.6mm nozzle instead of the default 0.4mm nozzle.
- I use the default smooth print sheet but there are different surface finish options such as a rough textured or Satin sheet.
- I originally got mine as a Semi-Assembled kit but I’ve torn it down completely once and swapped out the rotary encoder for the UI and one of the extruder fans.
- I have it on top of a concrete slab which rests on layer of foam to reduce vibrations and noise.
Angles¶
- Stringing galore! The combined print had tons of stringing issues. This was a mix of wet filament and needing retraction and temperature tuning. Prior to printing this I updated PrusaSlicer and accidentally reset my old custom profile. The default 0.6mm nozzle wasn’t doing the retractions as aggressively as I liked. If we ignore the stringing the overhangs themselves are not bad. Seems to hold up until 20°. A quick flashing with a lighter should clear these strings up and leave a relatively okay print. I fixed this for the bridging print by switching filament and upping the retraction distance and speed. Increased retractions do run the risk of leaving holes in the print at the start of layers. But it’s preferable to stringing.
Surface Finish¶
- Stringing as per the rest but the more notable thing here is the change from glossy to matte around the top surface. This part was one of the two tallest along with the single overhang meaning it had a significantly longer layer-time before the extruded filament cooled down.
Overhang Distance¶
- Stringy strings stringing. Top surface on this one is really messy. The 10mm top surface actually curls upwards slightly. Also noticing some ghosting on the letters. This tells me I need to check my belt tension and do a dimension cube and some ghosting tests.
Overhang Distance Closeup¶
- The overhangs break down completely at 8 mm and even start curling upwards at 9. This is mostly down to cooling. Part orientation matters with directional cooling. Results could be improved by tuning temperature and making sure the part is oriented so that the overhang is towards the cooling fan. Obviously it’s always best to design the part so that it can be printed easily by bridging or vaulting overhangs.
Single Overhang¶
- Not sure why I even printed this to begin with. I suppose it’s intended as more of a support test but I printed it without supports. Results are about as expected. Overhang droops completely but the top layers look acceptable. The surface finish on this part was significantly shinier just like the surface finish part due to it being taller than the rest.
Wall Thickness¶
- This one shows some of the 0.6mm nozzle’s drawbacks very clearly. The stringing is surprisingly visually pleasing.
- The wall thickness doesn’t change after .9mm and walls didn’t print below .2.
- The holes have gaps int he top-player surface. Probably a cooling issue as they shrink and don’t adhere to the wall next to it. Small details like this are always an issue with the .6mm nozzle as the outer perimeter walls don’t adhere to the infill. My go-to solution is to increase the wall count.
Bridging:¶
- Printed this one separately from the rest, switched filaments and tuned my retraction settings. It came out almost perfectly although the top surface finish is spotty but that’s mostly due to the .6mm nozzle’s extrusion width. Enabling ironing can disguise this.
Bridging closeup:¶
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- Bridging without issue. The Prusa is great when it comes to bridging thanks to the cooling setup but the orientation of the part does matter since the fan is directional. Note the strand of filament coming off the top. That’s an example of the oozing with the 0.6mm nozzle.