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3D Scanning and printing

Characterize our 3D printer
Design and 3D print an object (small, few cm3, limited by printer time) that could not be made subtractively
3D scan an object (and optionally print it)

This week I had chance to experiment with both FDM printers and SLA printers which are very different. I hope this little page may help people on both sides.

Group assignement

We began by charaterising our printers. We run a bunch of Test with Sylvain to settup the machines. We had to repaired it at the same time…

Our printers had several problems. First of all the were covered with sawdust leading to adhesion problems. Dust also cause damage to hotend fan. Which leaded to extrusion problem and clogged extruder.

We replaced fans and fixed extruders. Then, we were good to go at the lab.

We started the journey by printing this test on all of our printers.

Here is what we got in PLA :

As you can see, the default parameters of cura give a pretty good result with PLA but the PETG profile does a lot of stringing. Stringing happend when the plastic flow out of the nozzle while in mid air. The plastic will be pulled from one point to another and will cool down in place. As a result you may see a lot of thin plastic wire between vertical surface of your print.

To correct that effect I tried to sligtly raise the retract speed and length. After printing a line on the print, the extruder will reverse the filament to keep plastic flowing in mid air. I also lower the nozzle temperature by 5°C

Personal assignement

Cura slicer

First of all, let’s talk about the printing workflow. To print something, you have to follow this workflow :

  • Grab an STL file (3D model)
  • Import this fil into your prefered 3D slicer (Cura here)
  • Adapt slicing parameters to your needs (Speed, details, material, printers)
  • Slice and save the programm (Gcode)
  • Send the Gcode to the machine (over network or SD card)
  • Clean & adjust the buildplate
  • Check and load filament
  • Start the print

Cura is free and available here. Cura is a powerful 3D slicer whith a very active community. I also like the fact that its UI is more intuitive than slicer like Slic3r for instance. When you open Cura for the first time,

Alfawise U30

With have two Alfawise u30 printers in the fablab and Three Alffawise U20 printers. These printers are very cheap and are doing a good job. However there are not very durable… We had a lot of problem using it. I do not recommend letting them running autonomously… Be were of fire !

Anyway, These printer can print fast and are easy to tune. Perfect for public usage.

Menu Parameters Value
Quality Layer height 0.15 mm
Shell Wall thickness 1.2 mm
Top/Bottom thickness 0.8 mm
Infill Infill density 20%
Infill pattern Tri-Hexagon
Material Temperature 220°c
Diameter 2.8 mm
Flow 110 %
Speed Print speed 50 mm/s
Infill speed 40 mm/s
Outer wall speed 30 mm/s
Inner wall speed 50 mm/s
Travel speed 100 mm/s
Adhesion Type Brim
Brim width 8 mm


Ender 3 (+ BL-touch)

I also repaired my own printer which suffer from the moving house… A bunch of wires were disconected (Temperature sensor & extruder stepper motor)

First of all, I had a problem with the extruder. The stepper motor wasn’t running at all… I openned the board casing, and immediately found that both E stepper motor and Temperature sensor were disconected. I reconnected them and everything was fine.

Phrozen 4k mini (SLA)

docs\images\6_stl\3d-part.jpg docs\images\6_stl\3d-sliced-full.jpg docs\images\6_stl\3d-sliced.jpg docs\images\6_stl\allinone.jpg docs\images\6_stl\BLtouch.jpg docs\images\6_stl\cura-slicing.gif docs\images\6_stl\ender-open.jpg docs\images\6_stl\ender-temp-problem.jpg docs\images\6_stl\ender-wire-mess.jpg docs\images\6_stl\ender-wire-zoom.jpg docs\images\6_stl\failed-print.jpg docs\images\6_stl\fdm-wave.jpg docs\images\6_stl\final-prototype.jpg docs\images\6_stl\flexspline-proto.jpg docs\images\6_stl\full-vat.jpg docs\images\6_stl\fusion360-kube.jpg docs\images\6_stl\fusion360-nodes2D.jpg docs\images\6_stl\fusion360-nodes3D.jpg docs\images\6_stl\fusion360-tunnel.jpg docs\images\6_stl\fusion360-tunnelPath.jpg docs\images\6_stl\glass-flexspline.jpg docs\images\6_stl\harmonic-proto.jpg docs\images\6_stl\inclusion.jpg docs\images\6_stl\mars-sucess.jpg docs\images\6_stl\metal-ball.jpg docs\images\6_stl\opac-resin.jpg docs\images\6_stl\petg-test.jpg docs\images\6_stl\pla-sucess.jpg docs\images\6_stl\resin-bottle.jpg docs\images\6_stl\reverse-benchy.jpg docs\images\6_stl\safety.jpg docs\images\6_stl\screw-vat.jpg docs\images\6_stl\sla-ready.jpg docs\images\6_stl\sun-resin.jpg docs\images\6_stl\testing-parts.jpg docs\images\6_stl\wave-generator.jpg docs\images\6_stl\zero-button.jpg docs\images\6_stl\zero-process-start.jpg docs\images\6_stl\zero-process1.jpg docs\images\6_stl\zero-process2.jpg docs\images\6_stl\zero-screw.jpg

Last update: September 23, 2021