This is part one of a redesign of the cupcake using the ultimaker 3-axis setup. It's intended to be backwards-compatible with existing cupcakes, which is to say that you should be able to print out the parts here, modify your cupcake enclosure, and install; more on that in another Thing. The pictures show the arrangement for the cupcake, which should give a reliable build volume of 194mm x 132.5mm x 145mm, or about 2.5 times the build volume in the cupcake with no increase in exterior dimensions. However, using the same printed parts you could scale this to whatever you'd like.
It's also intended to use the Mk5/Mk6 toolhead with a short bowden-style extruder tube and the Gen3/Gen4 electronics (Gen4 strongly suggested).
For this assembly I decided to use threaded inserts for thermoplastic parts instead of the more common through-bolt arrangement; although it increases cost a bit it allows for blind holes, which was important here since space is a very limited.
This is still a work in progress - full parts list and more detailed instructions soon.
NOTE ON LICENSE: I haven't seen anything of the Ultimaker apart from the publicity shots, which is to say that I haven't done any work with the source files and I don't know what license they will be released under. For now I've gone with GNU-GPL so that this is compatible with the cupcake, but I'll update as necessary when the Ultimaker is released.
1) Print 10 rod adjusters, 1 each of the x-, y-, and center bearing blocks, 2 Z-axis rod adjusters, 4 z stiffeners and one each of the z supports
2) Clean up holes and enlarge the threaded insert locations to 3/16"
3) Assemble with parts purchased from SDP-SI and Mcmaster