I have uploaded on Thingiverse "robcap3V1" and "leftrobcap3V1" for to close the elbow of the forarm. This part is necessary if you plan to go on with the project of the complete arm. It also gives a finishing touch to the forarm...

Here you see it attached to the forarm, with the "elbowshaft1" glued on it.
It needs to be glued to "robpart5V2" or "leftrobpart5V2" depending on which arm you built.

I also changed "bolt" to "bolt_entretoise", because every body doesn't have aluminium pipes in his workshop to make some entretoise/spacer.
Here you see where they are meant to be used.