After having some difficulties with the Plastruder MK3 which comes with the MakerBot, I decided to try to print a better (i.e. more reliable) extruder with and for my MakerBot.

The design was inspired by the "Thermoplast Extruder Version 2.0" from the RepRap project and by photos I saw of Nophead's "Fast extruder" .

(Update: There's now a 4th part to print: InsulatorRetainer.stl)

Notice: This is a project in development, and I intend to improve it over time. This draft will work, but it's hardly ideal. Caveat Emptor!

Update Jan 31st: I've uploaded Version 2, which is pretty much the same as 1.5 (which I've removed as a result) but comes with the "Hex Key Holder", which can be fitted with a standard screwdriver bit from a powertool to act as a crude "center". My experiments with using two such centers to drive the lathe weren't great, as one invariably ends up spinning and the piece stops. So it looks like the required parts at present are: Two Bearing-End-Body Sections, two Bearing-And-Tool-Fittings, A Boltplate and a Hex tool holder. You'll also want a Dremel Rest and a length of MDF/wood to bolt it all down to. And you'll need googles, and perhaps gloves, and a lot of sense.
For now, it is left to the user to figure out spacing of the body sections and how to align them. I'm working on improving that. :)

More Update: Really bad video of me demoing Microlathe: youtube.com/watch?v=6XXN6UkrnIw and a shot of the finished piece of dowel on my Twitpic: twitpic.com/y8jnl
Also, Microlathe was featured on Makezine! blog.makezine.com/archive/2010/01/tiny_printable_dremel-powered_lathe.html

Microlathe is a little dremel-powered woodturning/watchmaker's lathe that can be printed and bolted together with all those leftover M3 nuts and bolts that came with your Makerbot. In addition to the M3 nuts/bolts, you only require a 608 bearing (I got an extra one with my Makerbot) and an 8mm diameter spring to fit the bearing-end. You probably don't even need that spring.

So, if you have a Dremel handy, you can consider this "The Lathe That Came Free With The Makerbot"!

Microlathe is Parametric, and makes use of a "Global Parameters" script from which the others derive shared traits such as the radius of the bolt plates, etc.. you could try printing a larger one, but bear in mind the limited space you have to print the body portions, which are already quite large for a Makerbot.

MicroLathe makes use of shapes.scad, which was kindly released to the community under the GNU General Public License by Catarina Mota. Permission was explicitly granted for shapes.scad to be considered released under an Attribution, Sharealike license additionally in this case, to facilitate licensing crossover. Thanks a million Catarina!
Microlathe also makes use of teardrop.scad, which was provided kindly by Erik De Bruijn. Teardrop.scad is released under the GPL2 license, with the inheritance clause generously waivered in this case to permit release under a non-GNU license. I'm very grateful Erik, thanks!

I'd appreciate a small donation via Paypal if you find yourself using this to generate a profit (selling turned items, etc.), or if you just love it and want to show your appreciation. Otherwise, it's all yours to print for yourself or others! Just don't charge for it without asking me and informing the buyer that it's available freely here.

An openly designed Creative Commons Licensed robot.

Note: New Version (Beta 2.1) posted 06/05/2009

New features: 12 legs instead of 8, "drop-in" center platform, 1:1.8 ratio gears, many small changes.

I only update this listing for major revisions of the walker, it's possible there's a minor revision posted at my site that is not here: 4volt.com/projects/jansen/

What you see here is the Jansen walker, a laser-cut robot, based on the Jansen Mechanism. It has 12 legs and scuttles similar to a crab walking sideways. The brain is a Arduino, and the legs are powered by 2 micro-servos modified for continuous rotation.

This project is heavily influenced by Theo Jansen's natural gearing mechanism, it’s a very efficient mechanical leg design for converting rotary motion into leg movements, and is very elegant in my opinion. The basis is the relative distance of the 12 joins, Jansen calls them "The 12 Holy Numbers". The numbers were developed with a genetic algorithm. In a couple of interviews that he wrote the evolver on a Atari STe computer and it took literally months of 1990’s processing power to find the solution.

For more info on Theo Jansen as well as some video and pictures see strandbeest.com.

I've marked this as non-commercial creative commons licensed, but it would be very easy for anyone get me to license a commercial version to almost anyone. For the most part I would just like to make sure I agree with the usage, and make sure I am aware of it.

See vimeo.com/4221721 for a video of the motion.
The home for this project is 4volt.com/Projects/Jansen/

Also, if you don't have a laser cutter, but would like a set of laser cut parts for this project see: 4volt.com/donate.aspx#jansen

For those whole like to ban things, this is a printed speldge hammer with the word BAN reversed out of the face.
Post about it on my blog: eagleapex.com/2009/11/01/ban-hammer-3d-printed/
Made at hive76.org

This is the second half of my openscad.org gear sets.

I couldn't get the top and bottom parts of the double helical to union properly, so I ended up offsetting the bottom piece by 0.1mm :( It skeins and prints fine though.

This thing is part of a set:
- spur gears: thingiverse.com/thing:1336

UPDATE: I'm printing some gears and noticed a couple mistakes on the openSCAD script: the variable 'orientation' wasn't doing anything and the value 'extrudeInDiam' was in fact being used as radius. They're both fixed now and I uploaded a new version of the script.

Even though there are lots of great gears on thingiverse, I couldn't resist the urge to model some too :)

The combinations of parameters are too many to upload an STL for each, so I just picked a few.

I also made a version for helical gears: thingiverse.com/thing:1339

While talking to Zach I got inspired to model lego bricks in order to create custom bricks - the ones you always wanted but thought you never could get. Well now you can!

Of course it does not snap in place as nicely as original lego bricks but it should be good enough to create the custom lego piece you always wanted.

This is the next step in my attempt to make a Sarrus linkage based 3D printer. The idea is to have a cartesian mechanism without those long rods and bearings.

I built three of the Mark III and mounted them in a x-y arrangement as shown. They can move over a square about 105 mm wide, and someday may carry an extruder. They are driven by DC motors taken from inkjet printers. These motors are driven in a servo arrangement using quadrature optical encoders and optical strips removed from the same printers.