3D printing my own head
Channel: Orion Lawlor
Date: 26/09/2012

I'm using my friend's older Makerbot Cupcake (heavily customized and upgraded with Stepstruder and gen4 Thing-o-matic driver boards) to print a 3D model of my own head.  Solid fabrication is really interesting technology, but it's currently pretty slow, taking 20 minutes to print a model less than an inch high.  On the plus side, it only used a few cents of ABS plastic, since the model is honeycombed inside.

Setting this thing up was really hard.  I'm a C++ programmer who uses UNIX and builds circuit boards for fun, I've built my own CNC lathe, and it was *still* hard.  The biggest problem was you can't tell if a given problem is hardware (jammed up pulley), wiring (which direction does that plug go?), electronics (bad motor driver), software (wrong control program), configuration (bad machine.xml), or just a bad model.  I had problems in each of those things.

The biggest issue is the documentation--it's clear and helpful IF you find the right page for your exact configuration.  Otherwise anything the documentation says is wrong!  For example, I had to work out that I had:
 - Cupcake stock mechanicals and steppers.
 - Stepstruder Mk6 extruder.
 - 3mm ABS filament.
 - Gen4 (2.4) motherboard w/ Arduino Mega 1280, upgraded to 3.1 firmware.
 - Extruder Controller v3.6, upgraded to 3.1 firmware.
 - Stepper driver board v3.3.
 - ReplicatorG v0037 (Skeinforge 50)
It's sort of a hybrid machine, which is cool, but I had to manually hack the ReplicatorG XML machine file and startup gcode to make things work.  I ended up removing all the "homing" stuff from the gcode and unplugging the limit switches, so I could just manually center the build platform and extruder at just the right height.

To keep the ABS from popping off the build platform after about 1/8" of build, I printed onto a pink post-it note, which provided a tiny amount of flex to keep the part from sliding off the build platform.  I need to figure out how to set up the heated build platform (HBP).