Sources for 3D Printer Files

Many of the parts we’ve made on the 3D printer so far have been ones we’ve downloaded, not drawn ourselves.  Given the huge number of 3D printer files available online it’s always  good idea to check a few sites first to see if someone’s already gone to the trouble to make up a file for the part you want to make so you don’t have to draw it up yourself.

Here are a few of the many sites where you can find files to use with 3D printers.  Since the 3D printers we have use .stl files look for that type of file first but it’s possible to convert other solid model file types (like files from Fusion 360 or Solidworks) into .stl files fairly easily.

  • Thingverse – I always check here first.  Models usually work great on our printer.
  • GrabCAD – most models won’t be in .stl format but there are many more engineering-type models here than on Thingverse
  • Turbosquid – never used it but appears to have lots of models, lots aren’t free though
  • stlfinder – search engine for .stl files, uses above sites plus others
  • yeggi – another .stl search engine

Feel free to send me links to other sites you’ve used to find .stl files.

Meissner Tetrahedra

I was contacted by Prof. Kyle Ormsby in the Math Department a while back about a project he was working on with his new 3D printer, a recent-generation Makerbot.  The idea was to create a few “bodies of constant width”.  A sphere is the simplest body of constant width but it turns out there are others as well.

Here’s the requisite link to the Wikipedia paragraph on Meissner Bodies. There are lots of cool things about these objects and this video really sums a lot of it up.  The cool thing is that they can act like ball bearings even though they’re not round.

Kyle wanted to make a few of these objects on his printer but it turns out that drawing them up into a 3D model is relatively complex.  I’ve been using Solidworks whenever I have the chance to help visualize projects or assemblies and it turns out that it’s great for this application as well.

Unfortunately I haven’t had the time (and I’m not sure I’m even capable given my level of Solidworks competency) to draw them up but the internet giveth in the form of GrabCAD, a site that hosts lots and lots of free CAD models the people have drawn up and posted.  As you can imagine, someone had drawn up some surfaces of constant width and posted them.

Meissner Tetrahedron from SW file drawn by GrabCAD user that I opened up using Reed’s Solidworks License.

Continue reading “Meissner Tetrahedra”