For those with difficulties rotating the Frame unit to print without supports.
This is uhltimate's original frame, just rotated to lay perfectly, and 0.1 trimmed off that surface to create a better 1st layer.

update 1/17/24: Very little tolerance was made for the parts to join, which required a lot of filing after print to join the pieces. So I increased the tolerance on the square hole of the spring to make it easier for people to join the pieces afterwards.

I printed a few for the kids. :)

Find original model here : https://www.thingiverse.com/thing:6394708