This is a new design for a Column Delta printer. It runs Smoothie and works great. (Ok, I'm really not a big fan of Smoothie, but the mechanicals work great.)
UPDATE 4-24-15 Up-rev'd some parts. Added an effector with a built-in 51mm blower fan mount, and added an E3Dv6 groovemount with integral nozzle blower duct to suit the new effector. You can print both to use together, or feel free to use an older effector rev without the fan mount.
UPDATE 3-23-15 Added thermal fuses to the BOM. Per the developers, Smoothie should NEVER be used without thermal fuses on all heated components, and is not intended for use by people unable or unwilling to design and implement adequate safety circuits. Smoothieware does not detect many common heater faults. Machine safety is up to the end-user.
Unlike normal Deltas, this printer uses a square frame rather than the standard triangular frame. This makes the arm/effector system slightly less rigid, but in exchange makes the frame fabrication and alignment exceptionally easy. Building a rigid and well-aligned frame around 90 degree joints is simply much easier than using 60 degree joints. This also makes the frame easier to reuse and convert to/from a Cartesian printer if desired.
In the future, I intend to add the fourth arm to improve drivetrain rigidity and speed. Some very high-end commercial Pick-And-Place Deltas use four arms to enhance speed and precision. All necessary hardware to do this is designed into the printer. But controlling the fourth arm will require some pretty significant firmware modifications, so it's on the "to do later" list for now. I may get around to it eventually.
Carriage/effector parts loosely based on the Mini Kossel. Design concepts and some STL sources were pulled from:
Special thanks to wolfmanjm for his work on Smoothieware code to implement updates to the Linear Delta kinematics to make the system easily configurable for non-standard tower positions.
BOM and SketchUp source model are attached.
Print motor brackets and preferably effector+groovemount in a heat-resistant material. (I used PET.) PLA is fine for everything else. None of the parts need supports if your printer can do decent bridging/overhangs.
Lasercut the base plate yourself or get Ponoko to do it for you.
I think all the required hardware (nuts, bolts, etc) is listed in the BOM, but no promises. Let me know if anything is missing. Assembly should be pretty self-evident from the build pics attached. Drop nuts in nut-pockets, insert screws, etc.
Smoothie wiring and configuring is pretty easy if you follow http://smoothieware.org/3d-printer-guide step by step. My custom config file for the square Delta kinematics and Viki2 panel is attached to this thing. Please review all settings and wiring before applying power!