Thames and Kosmos reinforcement piece for robot arm

The Thames and Kosmos Remote-Control Machines set's robot arm has too weak an attachment for the up-and-down (altitude) motion's worm drive--the upper part of the worm screw's axis is attached to a piece that has too much play, and the worm disengages the worm wheel. It would be pretty easy to reinforce this with a 5x hole piece and two studs, but there aren't enough studs in the set.

So I designed a simple reinforcement piece. In the photo, it is the green piece. You might want to adjust th