3D Scanning and Printing

This week we learn about and characterise our 3D printers.

In Wales we have a pair of Ultimaker 2+ printers. Now outdated, but still capable machines. We made use of the test files recommended by the tutor:

Test Article 1 Test Article 2

as well as a couple of parts from Neil's examples:

Neil's parts:

Using some of Neil's files. Slicing done with Cura, 0.1mm layers + support + skirt. Printed on an Ultimaker 2+.

Producing these parts we learn our printers limits in relation to neat overhangs and co-axial joints. For more on the results see the writeup from my '21 cycle group work.

Example test prints

For article two we made a comparison between two nozzle diameters. 0.4mm (standard) and 0.6mm. Two nozzle diameters were tested

Whilst printing the tall narrow overhang in PLA with the 0.4mm nozzle we noticed that the cooling was causing the part to 'spring back' into the nozzle. We aborted the print, as on the soft thin side, the nozzle was bogging down and the printed was kicking the print.

The tall narrow overhang had spring

With 0.4mm nozzle we can happily print over a 45 degree overhang, starting to get lumpy at 50 degrees.

0.4mm nozzle overhang

With a 0.6mm nozzle things start to get lumpy after 30 degrees. 0.6mm nozzle overhang

Using the other design to compare materials. PLA as reference. Test sample in PLA for comparison

PETG as an exotic material in comparison. Same in PETG

PETG living up to its reputation for being stringy. You need to manage retraction carefully for clean prints. PETG has a reputation for being stringy

Faulty print

We attempted a print using a 0.25mm nozzle, which seems to have exhibited almost all the issues that an FDM printer can throw up. An attempt with a 0.25mm nozzle

Excess material gathered up on the nozzle, breaking away and attaching itself to the part. Excess material

Excess extrusion on the nozzle. Collecting on the nozzle

More blobs given off. Resulting in blobs

Excess material can cause collisions, making the machine miss steps. Skipping

Here we see an example where the adhesion to the bed has been insufficient. Adhesion problems