Many people with disabilities such as cerebral palsy (not limited to CP) can grasp with their hand but not rotate at the wrist. This means that they can not draw or write on paper, as the the pen is usually parallel to the paper.

This device is designed to hold a pen or marker vertically while being held itself horizontally. By loosening the thumbscrew, the pen or maker can be switched out at will.

It uses a captive square nut and a thumbscrew to help maintain the pressure on the marker. The openSCAD file can be adjusted for different diameters, finger grip positions, etc.

This model is designed to accept the following parts:

Bill of Materials:
(1) 10-32 1" Plastic thumbscrew
McMaster-Carr Item#: 91185A386
https://www.mcmaster.com/#91185a386/=1ebxch4

(1) 10-32 Square NutMcMaster-Carr Item#: 94855A283  https://www.mcmaster.com/#94855a283/=1ebxdyp

However, any square nut the same size would be fine, any bolt or thumbscrew that fits the nut will be fine. The openSCAD file can be altered to adjust the size of the captive nut.

To insure the nut stays captive, thread the thumbscrew through the hole in the end through the captive nut. This will ensure the alignment is good. With the thumbscrew in place, fill the channel in which the captive nut rests with hot glue. Once cool, it will prevent the nut from coming loose even if the thumbscrew is missing.