My 10lb spool of 1.75mm diameter ABS plastic came today, in a lovely grass green. Next up is to design and print out a few parts to mount the spool to my machine. Then lots of big, continuous prints.
10lbs of 1.75mm diameter Green ABS plastic
Once I had the machine all hooked up and adjusted, as well as my machine parameters set in ReplicatorG, it was time for the first test print. This was around mid-summer 2010.
Machine all wired up for its first print
For the first test print everything was quite a tangle of wires and loose circuit boards. I had no fume extraction system like I do now, so I used a table fan and an open window.
First Print
The first print turned out pretty well. I printed the classic Unfold’s Self Portrait 3D scan. For this print, I basically just made educated guesses on my initial skeinforge parameters based on previous printing experiences with my Fab@Home, in order to establish a baseline to improve upon. I believe the layer height on this print was around 0.5mm. Since then, I have gone though a lot of meticulous calibration to achieve much better quality prints. Though, this is all a work in progress and I am still working to continuously improving the quality and repeatability of my prints.
In order for the ABS plastic to stick well enough to the polyimide film build base it needs to be heated to at least 100°C [212°F]. I purchased an Omega CN7500 temperature controller to provide power to the flexible heaters. One of the really nice things about this controller is that it features auto-tuning PID control so you will get the best temperature control without having to manually set all of your PID constants.
Wiring to the PID Temperature Controller
The blue wires connect to the flexible heaters, four per connector. Then the orange-ish wire is a J type thermocouple connector. I used connectors instead of hard wiring everything to make it easy to remove the build plate if needed.
Testing the Heated Build Base
First tests were successful after the controller ran through a few heating cycles in order to calibrate the PID settings. For the tests I was concerned about the EMI that would be generated from the relays turning on and off in the controller, so I placed it behind a steel block. This EMI could potentially crash the machine micro controller while running code. I had run into this problem on my Fab@Home by placing the temperature controller too close to the micro controller. This time, I made sure to mount the temperature controller out of the way, and I have not had any problems.
