Bee-bot bulldozer

I teach robotics to kids and Bee-bot is a must!
I though that it would be cool for Bee-bot to be able to collect objects from a track and place them in a corner. This could be presented as a recycling center, Bee-bot being the worker that separates plastic,glass,aluminum etc from each other.
Currently I have released two versions.
The first version (Bee-bot bulldoze plastic pin) has a plastic printed pin that is inserted in the hole at the back of the Bee-bot during installation(the plastic pin can be seen in the pictures uploaded). Depending on the use, the plastic pin might break at some time.
As a result, I designed a second version(Beebot bulldoze metal pin) that has a hole, in which you must glue(use CA glue) a 4mm threaded rod with a length between 10-20mm. You have the option to print one of the two spacers provided if you want to tighten the PLA part to the Bee-bot using a nut.

If this project gave you an teaching idea and made your life easier, please consider mak