This page is about my interests, projects, and profession (technical artist in the video games industry).  Most of my hardware\software projects are coded in PythonProcessing, Arduino, or MEL (Maya Embedded Language), in addition to 3d printing stuff on my Makerbot Replicator:  You can find my latest prints for download over on Thingiverse.

Speaking of Processing\Android\Python, you can link to my various programs\apps via the above title bar.

I also maintain several Mel\Python\Pygame\Processing wikis that I update far more often than this blog.  See them on their page.

All information on this site is copyright under the Apache Licence v2.0, unless otherwise noted.  Which means you can pretty much use the information here for whatever you like, but I always appreciate credit where applicable.

Have a look around.  Thanks for stopping by.

– Eric Pavey

New 3d print: Lumihedron

My previous “Dodecahedron” print was a trial run for making something bigger.  From my GeoLight print a year and a half ago, I’ve found the idea of making lighting via 3d-printing fascinating. Lumihedron is my current exploration.

Fully printed its diameter is just under 10″:  I designed a single pentagonal volumes to nearly fill the build plate on my Makerbot Replicator (1).  Each  volume took 4 hours to print * 12 prints = 48 hours of print time.  All PLA.

The whole fixture is held together via zip-ties except the bottom pentagon:  It’s held by neodymium magnets embedded into the print itself, held in place by super-glue:  By removing it, you can  replace the light.  A 60 watt Cree LED bulb is screwed into a repurposed shop-light from Home Depot fits perfectly in the top, while a custom printed clamp screws onto the base holding it in place.

I painted six of the twelve pentagons matte black on the outside, and gloss-white on the inside.  While looking pretty cool in person, they don’t photograph well, so have been turned away from the camera in all the below shots (you can see them in the window reflections though).  The other twelve pentagons are natural PLA.

I designed it in Autodesk Fusion 360, to help teach myself the software, going through 5 different revisions.  I’ve been enjoying the software, except the weekend where the cloud service went down and I couldn’t access any of my work:  They really need fix that ‘obstacle’ to design.

Really enjoyable & fulfilling project.


lumihedron_endtable_fancy lumihedron_tableClose_fancy

Small-scale 3D print tolerances

I picked up some small but powerful cylindrical magnets, 8mm diameter by 3mm tall, to incorporate into a new multi-part 3d print:  They’ll help hold the whole thing together.  I print mainly in PLA, and while it shrinks less than ABS, it still shrinks, so I needed to make sure that the cylindrical holes I design in my 3d model will actually allow the magnets to fit, based on how my Makerbot Replicator (1) prints things.

Using my micrometer, I checked the size of the magnets:  They were within a few hundredths of a mm of their spec:  Negligible change.

I designed & printed a simple rectangular volume to place my test holes:  It measured 60x30x3 mm.  In it I placed three different holes with diameters of 7.5, 8.0, and 8.5 mm.  For the record its print specs are:  300 micron layer resolution, 2 shells, 10% infill, blue PLA extruded @ 220 deg, HBP off, on blue painters tape.  My print nozzle is .4mm.  Took about 12 minutes, and was firmly affixed to the build platform before removal with no curling.

You can see the results below:


So what were the results?  Checking with my micrometer….

  • The outer dimensions of the printed rectangular volume were very close to the 3d model:  .1 mm larger (or less) on X, Y, & Z.
  • The printed cylindrical holes were each nearly exactly .5mm smaller from the 3d model:  As you can see from the above image, the modeled 7.5mm hole ended up being printed @ 7.0 mm, the 8.0 hole @ 7.5mm, and the 8.5mm hole @ 8.0 mm.
  • Because of this, the 8mm wide magnet fits snugly into the 8.5mm modeled hole, which ended up printing with a 8.0mm diameter.
  • Another interesting side effect:  Even though the rectangular volume and magnet were both 3mm high, and the magnet fit in the whole snugly but easily, I was unable to push it all the way through without some force:  I believe this is because the first few layers probably ‘squish out’ more on the build platform, causing a slight lip to form on the bottom edge.  Nothing a drill or file (or obsessive-compulsive magnet pushing) couldn’t fix though.

So this raises the question:  Why does the outer-volume of the rectangle match the 3d model within .1 mm larger, but the interior cylinders are all .5 mm smaller?

New 3D Print: Dodecahedron

Dodecahedron, created from 12 separate pentagon volumes. Each pentagonal face is circumscribed by a 10cm circle.
I’ve liked the concept of creating many small repetitious things that assemble into something larger: This is my first attempt at that. Modeled in Autodesk Fusion 360.

Printed on my Makerbot Replicator (1).

Get print info and downloadable files over on Thingiverse.


Based on my previous post of comparing different 3d apps for 3d printing, I thought I’d give Autodesk Fusion 360 a shot at making a simple hexagonal “trivet”:  My goal is to try to eventually cast this in aluminum, to see how well the small structures work.  But in the mean-time, things I learned:

  • How to create exacting-sized objects in the software:  It’s 100mm wide, and 5mm tall.
  • How to create my name & author year, and boolean that into the base of the solid.

Each trivet takes about an hour to print on my Makerbot Replicator (1), at 200 micron, with 2 shells, and 10% infill, using light blue PLA.  Took maybe… 20 minutes model?


3d Modeling Apps: Comparing Features

I wanted to compare some standard features needed for creating 3d models in regards to 3D printing.  While I’m well versed with Autodesk Maya, I’m always interested in other (free) option for more simple things.  I’m not expert at any of these:  If any info I’ve presented is wrong, or you know a better way, please comment.

My test was done on a Macbook Air, Chrome web browser.

The apps compared were Autodesk Fusion 360, Autodesk 123D Design, Tinkercad, & Clara.io

The features I’ll compare below are:

  • Boolean operations
  • Text creation
  • STL export
  • SVG import


Autodesk Fusion 360:

  • Overall thoughts:  The most powerful when it comes to solid model design.   Just wish I could get svg import working.  I feel like I’ve only scratched the surface.  I wish it ran better on my Macbook Air.
  • Boolean Test : Success
  • Text Test : Success
  • Bonus Test : Success
  • SVG Import : Fail
  • STL Export : Success

Autodesk 123D Design:

  • Over Thoughts:  Mixed bag… a weird split of features between the web and computer app.  I had a hard time with the user interaction.
  • Boolean Test : Success
  • Text Test : Mixed
  • Bonus Test : Web App Fail, Desktop App Success
  • SVG Import : Success
  • STL Export : Web App Fail, Desktop App Success


  • Overall Thoughts:  Feels like “Maya Light” : Will be interested to see what direction this software takes in the future.  Not really designed for solid modeling, but I thought I’d give it a shot.
  • Boolean Test : Fail
  • Text Test : Mixed
  • Bonus Test : None/Fail
  • SVG Import : Fail
  • STL Export : Success


  • Overall Thoughts:  Had the most fun with this one : While it has the most limited option for making custom geometry in the software, once you imported geometry it was fast and flexible.
  • Boolean Test : Success
  • Text Test : Mixed
  • Bonus Test : Success
  • SVG Import : Success
  • STL Export : Success

Detailed Results:



Boolean Test:

Create two mesh, overlap slightly, union together.

Result:  Success :  When creating new objects they will auto boolean if they overlap, nice feature.

Text Test:

Create text, change the font, apply a bevel/chamfer.

There is a Sketch -> Text menu that will create text as curves.  After creation while selected you can access the Create -> Extrude menu to pull it into a shape.  Video on YouTube showing off more complex stuff.


  • Easy to implement.
  • Huge selection of fonts.
  • History allows for changing of font after creation.
  • Easy to select top-faces for chamfer operation.


  • None, other than sluggish on my 4 year old Macbook Air.

Result : Success

Bonus Test:  Boolean Text

Using the above text and already-booleaned surfaces, I was able to successfully do a boolean subtraction of the text from the solids via the ‘Modify -> Combine’ menu, then changing the option to “Cut”

Result : Success

SVG Import:

There is a Sketch -> Import SVG menu.  However whenever I’d import one, nothing would show up.  Finally, but using the “Find In Window” option I could get it to show up, but the I would loose control of the camera, and software:  My guess is either it was infinitely small or big, causing a problem.  I tried SVG’s made from multiple different software, experienced the same problem :S

Result : Fail

STL Export

You can RMB on any “Body”, and access a “Export as STL” option.

Result: Success



There are two versions:  One on the web, and a desktop App.  Where noted below, I used the Mac desktop version.

Boolean test:

Desktop Version : Create two mesh, overlap slightly, union together.

Result : Success : The ‘Combine -> Merge’ boolean operation worked without a problem.  That being said, I found the user-interaction aspect of picking the objects in the correct order surprisingly confusing.  I would repeatedly do it wrong.  I also found it clunky trying to access the old shapes for modification.

Bonus test:  Subtract the results of the torus-union boolean from a cube.

Result : Success : Very clean subtraction result via ‘Combine -> Subtract’.

Text test:

Create text, change the font, apply a bevel/chafer.

Desktop version:  Fail : For some reason the desktop version doesn’t support text at all.

Web App:  Pressing the “T” button creates some default text you can place on the ground plane.


  • Easy to create / change size.
  • Easy to change text once created.
  • Seven different fonts to choose from (if that’s a ‘pro’?).


  • Selecting the edges for the chamfer operation is very tedious.
  • When I finally selected all the edges needed and chamfered them, it crashed the app.
  • Trying a chamfer again worked, but this time I did the inside/outside of the “O” apart from one another.
  • Once chamfer is added, unable to go back and change font/text.

Results: Mixed : Need easier way to select font edges for chamfer operation.  Need more font options.

Bonus Test:  Boolean Text

  • Web App: Fail : I was going to try this, but the web-app quit responding.  When it finally did return, the “Primitives” menu would load.
  • Desktop App: Success : Since I’d already made text in the web-app, I was able to open that project in the desktop app and successfully to a boolean-subtraction from a cube.

SVG Import:

Has a native “Import SVG…” menu option.

Authored both some text and a scribble in Inkscape:  Was able to import the scribble, but not that text.  But seeing that other software had the same problem, I’m thinking Inkscape is exporting bad font SVG files.

Result : Success

STL Export:

Web App:

  • Result : Fail : Have options to ‘Send To -> 123D Make’ (which I don’t have installed) & ’3D Print at home’ which gave me an error.

Desktop App:

  • Result : Success :
    • Has a “Export to STL” option
    • Also has an option to “3D Print”, which opens the Meshmixer app, presuming you have it installed.  Meshmixer has a stl export as well.



Boolean test:

Create two mesh, overlap slightly,  union  together.

Result :  Fail : clara.io’s ‘Model -> Boolean’ operations are listed as ‘Experimental’, and based on this simple test, it is a fail:  Even though the mesh are simple low-poly objects, no matter how I align them, I get a “Maximum call stack size exceeded (Operator Error: Boolean (Create))” error.

Text test:

Create text, change the font, apply a bevel/chafer.

Create -> Polymesh -> Text


  • Easy to create / change size
  • Easy to change the text once created.
  • Easy to create bevel via Text-shape’s ‘bevel’ option.


  • Only one font option: “Helvetiker”.  Checking the webs/forums, other people have been asking for more font types.

Result : Mixed : Needs more font options.

SVG Import :

Result : Fail : Doesn’t appear to support svg files.  Google searching didin’t turn anything up, and browsing the software itself didn’t show any type of NURBS / path tools : Looks like polygons only.

STL Export:

Result : Success : Has option to ‘File -> Export Selected -> STL’.



Tinkercad could be considered 123D Design Light.  But it does things better.  Also, it was the fastest performing software out of all tested.

Boolean Test:

Create two mesh, overlap slightly, union together.

Result : Success : Surprisingly easy to do (once you understand it) : You simply “group” the two objects.  They’re now ‘unioned’ together.  If you want to do a subtraction, change one of their colors to “hole”.  All history is maintained, and it’s easy to access the old shapes to tweak them.

Bonus test:  Subtract the results of the torus-union boolean from a cube.

Result : Success : Very clean subtraction results:  Both torus are set to ‘hole’, and grouped with the cube.

Text Test:

Create text, change the font, apply a bevel/chafer.

Basic Text Test:

  • Authoring basic text in Tinkercad is pretty painful:
    • There’s no font/text tool.
    • You have to drag in individual pre-created letters.
    • All caps, all the same font.
    • All have to be individual resized/shaped.
  • Overall fail.

Shape Generator Text:

  • Tinkercad has a “Shape Generator” tool that is actually quite robust.
  • You execute a “New Shape Generator”, and select “Text”.
  • The default gizmo has options for 3 fonts.  But if you “Edit” the tools source, you can access the JavaScript directly, and see where they’ve plugged in the fonts provided:  If you have your own svg font, you can upload it and edit the source to include it.
  • I was able to install a custom font by following these steps:
    • Found a font I liked from Fontsquirrel, and download it.
    • Go to their font generator page, Set the mode to “Expert”, then set the export format to SVG (only) : Down load your kit.
    • This gives you a zip you can extract.  Then back in Tinkercad you “Edit” your Text Shape Generator, and follow the instructions towards the top of the main.js script for installing the new font.
    • Success!  Sort of:  The app kept giving me a warning, but everything seemed to work.
  • Overall : Mixed : While it gives you the ability to add new custom fonts (which none of the others appear to provide) you still can’t bevel/chamfer them.

Bonus Test :

I booleaned all sorts of text and shapes together.  Super easy.

Result : Success.

SVG Import:

Tinkercad has a Import menu that allows you to browse to a svg on your HD, or from a URL.  Example video on YouTube.

Authored both some text and a scribble in Inkscape:  Was able to import the scribble, but not that text.  But seeing that other software had the same problem, I’m thinking Inkscape is exporting bad font SVG files.

Result: Success

STL Export:

Result: Success : Very to export via the ‘Design -> Download for 3D printing’.  Note this downloads the entire scene.