I disassembled and reassembled the Printrbot+ this weekend. I’ve now upgraded it quite a bit, with accuracy and speed in mind. It now uses GT2 belts and molded polycarbonate/brass pulleys in place of its stock XL belts and printed pulleys, and Acme leadscrews instead of the original threaded rod. Aluminum 5mm-6.35mm couplers connect the leads crews to the z-axis motors, instead of the original set of molded plastic couplers. I bought all of the parts for this round of upgrades from techpaladin.com. Nathaniel was super-helpful, and informed me of parts I’d need that became in-stock just before my order shipped and in time for me to add them.
The result of these upgrades make me very happy. First I printed a popular test object, Mr. Jaws. It went so well that I decided to push the envelope and drop the layer height setting from .4mm to .2mm. This higher-resolution print took twice as long (~27 minutes vs ~14.5 minutes), but the edges of the print are much smoother and the ridges much less pronounced.
This morning was time to try printing Yoda Lite. I brought its STL file into the program “Slic3r” to convert it to the geode commands that drive the Printrbot+, with layer height set to .2mm, and the software predicted a 2 hour print time. I lowered the fill percentage to .3 from .45 so that the object would be more hollow, but it still was going to take more time than I had if I wanted to arrive to work on time. So I set the object to print at 50% scale and the time estimate dropped to about a half-hour. Capital.1
I had one abortive print attempt in which 1/3 of yoda printed and then the object stuck to the extruder nozzle and popped from the bed. In order to prevent this from happening again, I adjusted the z axis endstop to print the first layer slightly lower and more flattened by the extruder into the kapton surface of the print bed. You can see this flattening in the circle of plastic or “skirt” around Yoda. It’s a little more flattened than I’d like, as every subsequent layer also gets flattened and the detail in the print is affected, but I wanted it to really stick to the bed this time. The result has some problems around the ears, but made me happy nonetheless. It’s a definite improvement over the pre-upgrade prints.
- Never used that one before, but “Yay” just didn’t look very professional. [↩]