Drawbot 3D printables now online
Motor mount bracket. Put some 30mm offsets into the motor, put the bobbin on the motor shaft, attach the mount to the offsets with some M3 nuts and then screw the mount to a board. The bobbins will just barely avoid the bracket and get the strings very close to the board.
Pen holder. Crude. This is my current area of research.
If you have better models, comment below!