Tag Archives: bill owens

On Wonky Geometry

The Faire Play Kickstarter is doing great: 17 days and 8% to go! Go give it some love if you’d be interested in seeing Barbie don some 3D printed medieval armor.

The Athena Makeover Kit’s been out in the wild for twelve days now and there are several photos of prints floating around the internet. I’ve collected two of them here.

First: Bill Owens’ print of the AMK with a cut-down spear to fit his printer’s bed, with tunic hand and machine-sewn by Maddy. Nice job, Bill and Maddy!

Bill has made some suggestions for improving the boots, which I’ll be taking into account when I release the final STL files to backers at the end of the Kickstarter.

owens large

Second, Josh Ajima’s hot-pink Aegis print, shown here with a Percy Jackson figure. Love this one.

percy jackson

Josh also made a modification to the aegis clip that will help it fit other Barbie dolls with inflexible wrists. You can download it from Thingiverse. Creative Commons licensing roolz.

5mm clip

Mr. Ajima blogs at DesignMakeTeach.com, and has all kinds of great resources for STEM educators over there.

If you’ve printed an Athena Makeover Kit, Send it my way with as much info about yourself as you care to reveal, and I’ll get the photo up on the blog toot sweet.

Early printers of the AMK might have noticed some fugliness at the intersection of the shield and medusa. To wit:

aegis fail

I’ll fall on my sword for this oversight; my initial prints handled this intersecting geometry just fine, but other folks using different slicing software have had some problems with this. Here’s what it used to look like in wireframe:

bad geometry

See how the medusa is just kind of jammed into the shield face and creates some intersecting geometry? That’ll print, sure, but it’s a less-than-optimal solution to the problem. We here at Zheng Labs prefer to minimize less-than-optimal solutions.

So! Here’s what it looks like now. I’ve welded the vertices together and now the mesh is watertight as the proverbial frog’s ass.

joined geometry

The final print result is now much improved. Go on over to The Forge and Download the latest and greatest model.

aegis better

Can’t wait to see your prints.

Printrbot Z-Axis Knob, Refined

I find myself adjusting the height of the Z-Axis on my Printrbot Simple with every print, sometimes during the print itself. Handling the leadscrew directly can get a little uncomfortable, so having a knob attached to the top of the axis helps a great deal.

Printrbot Z-Axis Knob

downloadThis knob is based off Bill Owens’ Printrbot Simple Z-Axis Knob which is in turn based on jridley’s Parametric hex head screw or nut knob. Circle of LIIIIIIIIFE

This version has some rounded edges for comfort because I’m a delicate desert flower that only blooms once a year and I must preserve my girly hands for stroking my Shih Tzu.

Did you hear about the new zoo that opened in Chicago? It’s only got one animal: a dog. It’s a Shih Tzu.

This knob also has some transitional elements between the two major volumes, and a graceful inverted flare on the shaft. These are completely unnecessary aesthetic changes to the perfectly-usable model made by Bill Owens, but since complexity is free in 3D printing, why not.

Here’s a perfect demonstration of how the Creative Commons license fosters creativity. First, in need of a knob, jridley throws together a parametric design and shares it on Thingiverse. Now anyone can adjust a few numbers and get a printable knob.

Standing on the shoulders of that giant, Owens refined the basic design until he got a knob he could use in his particular situation. He puts it up on Thingiverse where dozens of Printrbot Simple owners download and start using it.

I don’t know much about OpenSCAD, the software jridley used to design the original knob. But I can take the output into software I’m familiar with and edit the geometry to fit my needs.

All legal, all free, no ethical quandaries or patent fights. All we have to do is give each other credit where credit is due.

I found Owens’ knob to be a little loose given the crop of nuts grown in my part of the world, so this model might be a little tighter or looser for you.

You will need a pair of 5/16″ nuts to use this knob properly. Put one nut on your z-axis leadscrew, attach the knob, and then tighten the second nut.

The model is also available in The Forge along with assorted other baubles.