[Kevin Kolodziej]

We experimented with printed gears prior to the 2013 season but ended up not using them due to strength concerns after testing. These were intended for drive gearbox main gears. We did have a few polycarbonate gears printed by a sponsor and those held up just fine during testing but opted for a different ratio in the end. These were 20dp gears, 1/2" face width.

We successfully used 3D printed gear box plates for the entire 2013 season though. Those were 1/4 thick, solid ABS from a Dimension 1200 BST printer.

In 2014 we used printed ABS PULLEYS (not gears) for our roller claw intake without any issue the entire season. The prints were done as two halves with steel dowel pins (1/16" diameter) between the two halves with press fit holes. The pulleys were impacted during rough play and even held up just fine when a screw on the roller claw wheel backed out - and the mechanism proceeded to bend the screw past the mounting point and continue to operate. No ill effects on the pulleys at all. The files were printed directly from the Vex CAD files for the pulleys (I believe they were 32t, HTD profile). The only modification we made was adding a 1/2" hex bore. Bore was oversized by .001" or .002" and we ran a 1/2" broach through the bore after completion to smooth out any deficiencies in the corners.

In 2015 we lost access to the Dimension machine but were awarded one of the Ekocycle printers. We printed some Vex EDR sprockets with 1/2" hex bores to run chain from our tote elevator and our can arms to encoders and potentiometers. This printer isn't quite as fine as the Dimension printer so we oversized the hex hole by .005" but took the tooth profile directly from the Vex CAD files and they worked great all year.