This is an old revision of the document!


3D Printers

printers.jpg

Never leave any filament 3D printer running unattended.

:?: These machines are maintained by members of the Digital Fabrication Cause. Please speak with the listed maintainer before trying to maintain them.

filament.jpg It is expected that you pay for any filament that you use for the 3D printers. Octoprint will automatically calculate the time taking into account the estimate print time, and filament usage. The below filaments are compatible with our printers. If you have been authorised to use your own slicer, please use an approximate cost of $40/kg of filament when calculating the cost. If you've been authorised to use your own filament, please donate approx $2/hr for printer usage and maintenance.

We do not recommend people print with this as PETG is a generally a better alternative for most situations. ABS is very strong and has high heat tolerance. It has a glass transition temperature of around 100 degrees which means this is when it gets soft. However, it's plagued by warping problems and is notoriously difficult to print with.

PETG is recommended over ABS as it's nearly as strong but has slightly less heat resistance. It's much easier to print with and does not normally have printing or warping issues. It has a glass transition temperature of around 80 degrees.

PLA is the most brittle and weak of filaments and also has a fairly low glass transition temperature of around 60 degrees. PLA is recommended for it's ease of printing whenever you don't need the strength or heat resistance of PETG.

These people know the ins and outs of 3D printing and are generally happy to help out when needed:

  • Brendan Halliday (@nogthree)
  • Aaron Bycroft (@Sgt.Dicks)
  • Drew Spriggs (@dreadnought_strength)
  • Jaimyn Mayer (@jabelone)

If you consider yourself in the know, add yourself to the list! (but ask one of us first so we can keep track)

If you follow these basic design tips when creating 3D models, you'll get the best results:

  • Avoid overhangs - the printers work by building up plastic layer by layer, it can't lay down plastic into thin air! (or can it?)
  • Shallow overhangs are OK - anything steeper than about 30 degrees from vertical will have poor results. (ie |/ between those two lines should be <30 degrees)
  • Use “Bridges” - if you have a gap between two sections (ie |-|) it can normally be “bridged” as it's supported on both sides. Bridges <1-2cm work best.
  • The vertical (Z) axis is weakest due to the layered design. Try to design parts with the X/Y axis bending/taking the force instead of the Z axis. Think of Lego blocks, it's much harder to break a single long piece than a tall stack of short pieces.
  • If you need something to fit together exactly, make it slightly bigger or smaller than necessary, depending on how it's supposed to fit. 3D printed parts generally don't produce 100% dimensionally accurate parts (but are pretty darn close for most stuff).
  • Don't be afraid to use bearings, screws and nuts/bolts. If something needs to turn use a bearing, plastic on plastic isn't smooth and won't last. If you need to attach parts to each other or something else, using screws or nuts/bolts is fine. (remember the tip above, try to clamp/compress layers, not split them)

HSBNE's fleet of 3D printers are maintained by members who volunteer their time to keep the machines working so that you can print things. All of our printers have personalities and battle-scars, so before you do anything to maintain them it's worth checking with the maintainer first. There could be specific models for replacement parts that you need.

When using the 3D printers it helps the maintainers if you clean the bed when you're done, a wipe-down with some IPA (isopropyl alcohol) will clean the bed on the Taz. A sharp razor blade works well at removing old bits of glue, hairspray, etc from the heated bed of the CR10 machines. Please be careful as razor blades are sharp! A wipe down with IPA afterwards is not a bad idea.

Try not to leave any debris or print detritus around the printers too, as they may get caught up in the mechanical parts, and mess attracts more mess. Don't see a profile that works for your printing needs? Check out the Octoprint Configurations below.

Octoprint is set up on each machine to use Cura as its slicer.

The slicing profiles for each machine are stored in their own branches in this github repo: Configuration files for our 3D printers

This used to be the case but hasn't been updated in a while. If you'd like to fix this please let us know!

This cron job will remove all print files older than 7 days. Without it, the Octoprint interface fills up very quickly. It's here for reference:

# Remove all stl/gcode files older than 7 days
0 0 * * * find /home/pi/.octoprint/uploads -mindepth 1 -mtime +7 -delete
  • tools/digitalfabrication/3dprinters/home.1601208303
  • Last modified: 4 years ago
  • by nogthree