In general, most of the tolerances for printing the autotester are unremarkable. However there are a few items to consider in printing the objects.
- Color – Some parts such as the mixer stand and the carousel top and bottom need to be printed in white. This is because they are the backdrop that is used when analyzing the color of a solution. It is recommended that the remaining parts be printed in either white or black. This is to avoid introducing color variations into the analysis process due to reflected light off colored parts.
- Strength – The gears are 3D printed. Although these are not high speed gears, the plastic needs to be strong enough that they will not break or wear down. I used PETG, nylon will certainly work. ABS may work (although there is a risk that teeth will break). PLA is probably too soft. The gears and threaded screw were printed at 100% fill. Other parts were printed at 20% fill. Note that the carousel base is a gear.
- Supports – in general, supports are not needed. The only exceptions are the carousel stopper and the mixer stopper, which should be printed with supports.
- Resolution – Most parts were printed with a layer height of .25mm, except the screw thread which was printed at .2