There are some safety issues with the current iteration of the RepRaTS scooter.  There are a number of exposed threaded rods which present a hazard, especially on a motorized vehicle.  The lack of steering rigidity can make the scooter difficult to handle at times, and the exposed wiring presents some safety concerns.  I am in the process of fixing these issues.

All of the cad files for the scooter are available in the linked OnShape assembly.  All of the prints were printed in PETG with a 0.8mm nozzle at 0.4mm layer height with a 30% grid infill.  No parts require supports.  If you need supports, check your print orientation.  The parts labelled "plug" are meant to be glued in place.  To do this, first align the plug and spacer against a reasonably flat surface, and then glue with a wicking superglue.  I like to use Loctite 408 because it dries clear, but any superglue should work fine.  Also, the part labeled "steerer_tube" is meant to be superglued to the forks using the same procedure described above, to improve rigidity.  The motor controllers are placed in the housing and then zip-tied using the empty mounting holes on the scooter's neck above and below the controllers.

https://cad.onshape.com/documents/5c75d8bdd0fee75dc4319205/w/8036154f3c635b92e20f56a1/e/dee311946e14a8120c067eab

The key to this build is using tension in the threaded rods to give the beams strength and to keep the printed parts in compression.  The printed parts should not deform up to the max recommended torque for 3/8" low strength threaded rod, so do not be afraid to tighten aggressively.  Make sure to evenly and slowly build up to the max torque to avoid warping the beams as you are tightening.  If you find warping the frame to be an issue, simply back the nut out until the warping goes away and try again to tighten evenly.

The steering spacer height may need to be tuned to allow adequate tension in the three threaded rods without seizing the steering bearings. Ideally the bearings rotate freely with minimal slop when the threaded rods are fully tightened.