ACA Week 2 update

We have 3D printed most of the essential components of the swerve gearbox. The 3D printer has been working really well and we were able to complete a lot of jobs without monitoring the print at all times. There was twice the SR-30 support material was jammed and I had to untangle the materials, but that was due to the way the filament was wrapped when it was first shipped to us.

Below are some pictures of the gears and components we have printed:

We also printed the drive shafts for the gears that are not featured in the pictures above.

Overall I have been using 100% density and 5 shells in Balanced mode to print all of the parts, considering that they all take on some torque and I wanted to ensure the structural integrity and maintain the durability of these parts. From the tests we ran this Monday exploring the 3D print qualities, it appears that there is not a significant difference between Solid mode and Balanced mode at 100% density. Since there are small teeth on the gears and pulleys, and the extrusion sometimes does not fill the gaps between the inner circular shell and the exterior teeth shell well, I used 5 shells for all of the parts to strengthen the teeth on the gear.

The longest print job was 27 hours for the pulley and double gear. From the monitoring camera of the 3D printer, it looks like the wall behind the indented teeth around the pulley are really thin, maybe about 1 mm or less. I have not yet had a chance to confirm this as the Fab Lab is locked on Sundays. The other print jobs usually took 5 to 15 hours to complete. The gears took a shorter time, some less than an hour because there are fewer components in one job.

We realized that we have to apply glue on the build plate before each print job because the filament would not stick otherwise. It is a surprising solution as all MakerBot sent us was a regular glue. The glue solves this problem pretty nicely. The only issue with gluing the build plate is that is it difficult to clean the glue on the build plate. We were using hand sanitize gels to do so, and it seems to work better than using acetone or rubbing alcohol because the gel prevents the glue from turning to a solid and is easier to rub off with the spatula that came with the printer.

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