My 1st 3D printer was a success, and right after getting it working I had moved onto my next printer. I had identified that the convention was to overbuild printers, for example, there is a commercial printer that can mill aluminium if a spindle is swapped out for the extruder, which I find ludicrous! I wanted to experiment with a few methods of getting the cost down:
Axis Drives: The printer uses braided fishing line and an M8 bolt instead of timing belt and pulleys, which worked pretty well. I did, however, find that the fishing line slipped over time, so I introduced a few lines of G-code after every layer so that it homed itself to reset its position. I concluded that fishing line could be used effectively, however, it would have to be fixed in place on the pulley to ensure that it wouldn’t slip.
The rack and pinion drive worked very well, and the only issue that I had was how difficult it was to get it perfectly parallel to the motion of the axis. The main issue is that the axis has to be built in such a way that it limits the range of movement, so if it was used it would compromise the range of motion.
Linear Rails: I saw the v-groove on flat bar as an interesting idea and wanted to test it. I used steel rulers for the X-axis and aluminium angle iron for the Z axis. Both have stood up to thousands of hours of printing with almost no wear.
This printer was a fantastic workhorse and aside from the small slipping issue it was a perfect machine.