Replacement head for Ultimaker to allow the use of the E3D hotend.
This allows jam free printing at elevated temperatures for PLA, ABS and PC. It can also go phenominally fast. ABS at >150mm/s is no problem, as you can run it at 265deg. This also gives very strong parts with superb surface finish.
It has mounting points that replicate the lower Ultimaker plate, so as you can attach your favorite cooling fan. The E3D head is held in with a single screw and captive nut.
YouTube link of my first version printing here http://youtu.be/5YNZmCaw0O4. Apologies for the poor camera work!
With thanks to Sanjay at E3D for his support!

Please see the fanduct optimised for this head
http://www.thingiverse.com/thing:131647

Click "Open in Customizer" to turn the image of your choice into a Lithopane! We used the Mona Lisa, but you could use any photo you want. The Lithopane tool generates a 3D model that looks like a rough terrain map.

Download the file, print it on your MakerBot Desktop 3D Printer, and you've got a picture perfect pane to hang on your window.

Three cheers for the lithopane pioneers on Thingiverse, such as cymon and pp3dpNL! For more information on this old art form, check out the Wikipedia article here: http://en.wikipedia.org/wiki/Lithophane

Have you ever wondered how an automatic transmission works? I did, so I looked it up and then designed this desktop model. It has six forward speeds and one reverse. Real automatic transmissions have a hydraulic or electrical system that engages different clutches and brakes to shift gears depending on the driving situation. With this model you control those simplified brakes and clutches yourself.

The clutch is actuated by sliding the drive shaft through to different positions (which each have two gear markings), while three separate brakes each also have two gear markings. You select a gear by engaging the brake and clutch position associated with your desired gear. See demonstration video: http://www.youtube.com/watch?v=-FyC3dn3HJY

I tried to design the gear ratios to be fairly close to what some real cars use, and this is the result, where the input is the crank and the output is the annulus:
1st gear: 1 : 4.29
2nd gear: 1 : 2.5, 71% increase
3rd gear: 1 : 1.67, 50% increase
4th gear: 1 : 1.3, 28% increase
5th gear: 1 : 1, 30% increase
6th gear: 1 : 0.8, 25% increase
Reverse: 1 : -3.93

The OpenSCAD file is included and is highly parametric in case you'd like to play with different gear ratios. If you select a different number of teeth, it will print out the resulting gear ratios at the beginning of the output. I also used Matlab to investigate more thoroughly how the gear sizes affected the various ratios. I used transmission.m as an aid in optimizing the ratios to be somewhat evenly spaced.

This was all printed in PLA at 120 mm/s on a Replicator 1 with Sailfish firmware, default layer height (0.27mm). Everything came out perfectly on the first print. I swear, complex models don't have to be difficult, and who needs glue when you can print snap-fits?