This is a set of files to make the 3D printed parts of a 2D "delta" kinematic drawbot.
It will need a few extras:
- most bolts are M3, you'll need a selection of bolts and some nuts with some grubscrews in the same size
- "shoulder" bolts are M8
- small bearings for elbows and wrists (4x for each elbow) with 3mm centres
- large skateboard bearings for the shoulder joints (4x in total) with 8mm centres
- timing belt (T2.5 I think)
- NEMA17 (or 14?) stepper motors
- stepper controller board - my code is designed to use the Eggbot EiBotBoard
- 6mm carbon rod, around 1m total for each arm but this depends on how big you want the machine
- pen lift servo is a standard micro servo
Pulleys on the stepper motors are taken directly from droftarts' excellent pulley library, the arm pulleys are modified from the library so I've marked this whole thing as a remix.
Probably around 0.2mm is best
What you like, 20% or denser probably
Holes, fittings and assembly
Holes will mostly need to be reamed to 2.5mm and tapped M3. You'll probably need to ream the rod holes to 6mm to fit the carbon rods in. Nut slots should be OK to just drop M3 nuts in but depending on your print settings they might be tight. You shouldn't need support material for any parts.
The servo horn might need modifications to fit the pen linkage, I had to bolt mine in place with very small bolts but epoxy might work for you.
All parts were created in OpenSCAD, some parts have extruded DXF files created in Inkscape which should be included. The code is not very nice so don't laugh at it.
The drawbot is run from a very rough Processing sketch that interfaces with the EiBotBoard via USB. It will draw SVG files from Inkscape. It uses the geomerative library for Processing for SVG reading which doesn't seem to work in recent versions of Processing, I use Processing 2.1.2(32bit) on Windows which you should be able to download.