Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:3455568.

Couldnt get the bearings needed for the MTvplot project so i just made my own, two halves glue together (carefully!) using standard superglue, extra care is needed in doing so as you do not want to glue the tube to the gondola arms.

Pen holder then just glues on the outer tube using superglue as well