This is a penholder for a polargraph plotter. It has a Nema17 with an excenter for pen lift and uses 2 small deo rollers for pen lift instead of a servoand servo arm.
Here you will find a short video: https://www.youtube.com/shorts/AHvNnPZwCPw
There are 3 inserts. They can be used for different pen or marker diameters to bring the pen tip as near as possible in the center of the pen holder.
All parts are printed in PLA with 0.15mm layer height, 4 perimeter and 5 top and bottom layers. The motor mount only needs support.
The 5mm pin has to be glued into the excenter.
You will need the following tools:
12mm drill or reamer to clear the 12mm bores in the motor mount
5mm drill or reamer to clear the 5mm bore for the pin in the excenter
M4 screw tap for the setsrews in the excenter
You will need the following additional parts:
4 6805 ball bearings
2 pins 3x25mm for the levers
2 setscews M4x8 for the excenter
1 pin 5x20mm for the excenter
1 screw M4 x 25mm for pen fixing
1 nut M4 in the motor mount
4 screw M3x8 with washers for Nema17 fixing
1 Nema17 steppermotor 22mm with a shaft length of 20mm
2 roller similar to https://www.pharmaglas.ch/glasprodukte2/deo-roller/deorollerrollon10mlklarglaskomplett.php
The author remixed this model.