I started building a McWire. Gave up, around the time I got a full-time job, and picked up with a beta set of Printrbot parts. Now that I have a working machine, building another...
Build log: McWire
I began in 2007-2008 sometime building a McWire, using the laser cut parts from the RRRF and mostly ordering parts from McMaster. I got the X and Y axes done, but had to put it on hold because I moved from TX->CA.
Recently (April 2010) I picked it up again and have the mechanical build complete (as of July 2010) and the electronics check out. Next up:
- Extender/adapter cables for the steppers (with 1/4x20 leadscrews, NEMA-23 seems overkill and I'd like to use my NEMA-17 motors that have .100 headers)
- Experimentation with wooden leadscrews or larger metal ones (although I'm concerned with the weight); getting an ACME tap leads to all sorts of options here, but high torque requires better anchoring to the motors or explicit bearings.
- Experimentation with ball chain and thermal paper cores (the spindle around which receipt paper is wound -- they have 12 segments internally and the arc of each segment is very similar to the ball chain pitch -- I'll post a picture). EDIT: these ended up being very low precision, and abandoned.
Build log: Printrbot
In March 2012, I picked up a beta set of parts for the Printrbot. They were really rough around the edges, so I have endstops held on with sheet metal and holes drilled into the printed parts, painter's tape, and Lego. It works fairly well, but the base forms a parallelogram and doesn't play nicely with fast Y moves. Next up, I've printed the parts for a Mendel90 and hope to get that working a bit more reliably.
Currently running with Generation 6 Electronics and NEMA-17 motors (smaller ones than I originally intended) with a Greg's Wade's extruder, for 3mm filament. PLA prints about 90% reliability, ABS more like 30% (very dependent on outside weather conditions, and without a bed mosfet it's a bit difficult to manage the temps).
Build log: Mendel90
Sept 2012, hope to start soon.