This device was designed for those with disabilities which impair finger motor function, but still have some use of the shoulder and arm to use a basic Up, Down, Left, Right, pointing device.
Particularly those who would benefit from one such as this, that does NOT require precision motion. General UDLR motions accomplish the needed functions.

Paired with a Head-tracking Mouse Software such as the one found at CameraMouse.org, users can have a quick way to provide a left and right click vs Blinking or Smiling. Up and Down can also be set to things such as "Scroll up" or "Scroll Down" "Forward" "Back" or any other function that the user requires or uses often. The aim is to improve those users in this particular niche a 5-10x faster interaction over tedious blinking or smiling. Which is known to be inaccurate and sometimes aggravating to use for large projects. This can cause headaches and jaw stress for heavy PC users or those who require a PC for work.

This design is set up to remain centered at rest with the weight of the average arm sitting atop it. With the base piece clamped or attached to the desk itself.
Only about 1/4 to 1/2 inch of movement is needed to select a direction for an action to be triggered. But the light base needs to be affixed to a hard surface to function properly and not move around too much.

Using a USB Keyboard Encoder, and Antimicro software for Windows, we can set the directions of the VMA1 (Visual Mouse Assist 1.0) to any function the user needs.
https://www.amazon.com/gp/product/B07BQGH8CL/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
https://www.tonyknowles.com/antimicro/

Paired with a Simple Sanwa or Uxcell Joystick, with the ball removed.
https://www.amazon.com/gp/product/B07WCKM2VM/ref=ppx_yo_dt_b_asin_title_o01_s02?ie=UTF8&psc=1

Also, I used some simple tapered head M4 hardware to secure the stick into place, and the top to the baseplate.

All the mounting holes for the stick to the palm rest, and the top plate to base, are left out, so you can drill them out based on what hardware you have available.

The Height of the stick can be set using washers to drop the stick further into the frame. You can also set the at rest angle using washers as "Shims" to better center the stick to the at rest position. In case the users arm shape causes a forward or backward tilt inadvertently.

Drill the holes slightly under-sized and allow the screw threads or those of the joystick post, to cut their own threads. You can use 2 part epoxy to secure the palm rest permanently if desired. Though it does stay attached fairly well into just a well drilled hole with self cut threads. There is a small ledge on the base where the Keyboard Encoder will be mounted, and holes will also need to be made for this. As there are many different ones/styles, I left a lot of these mounting locations generic. So a variety of off the shelf sticks/encoders should work with this design with little modification.

Glue/epoxy can also be used to bond the top to the base, though a screw may be the way to go for those with larger palms, and a heavier arm.

All sketchup files are included, for modifications and customization to suit any need or body type.

The Palm rest, can be scaled up/down to the size of the users hand using the measuring tool in sketchup and the scaling tool. Take a few measurements of the hand, from the base of the palm to the first knuckle of the index finger, to set the length to scale, and the width of the palm at the base of the fingers to set the width to scale.
This should be fairly comfortable for most users. But again, please customize as needed.

I am NOT the best 3D artist and my understanding of Sketchup is still somewhat limited.

PLEASE FEEL FREE to remix these parts for more ergonomics and comfort, and redraw the parts for easier printing if you have the time. I am sure those who end up using this design will thank you. As I do!

Please make whatever use of this design you can to improve the lives of those you feel it would help. I seek no compensation, and offer this part freely to my friends in the maker world and beyond.

Enjoy!

Creality

Ender 5

No

Yes

.20

20-40%

Be VERY mindful of sharp edges on the plastic if using a brim to print the parts. Trim the corners with an X-acto or rough them down with sand paper.

Painting is ok, but use a durable product that won't rub off, and is non toxic.

Do NOT Paint the Palm Rest.

It can be lined with Felt or Sheepskin for comfort, but you may want to use a band of thin rubber matting or cabinet liner cut to fit between the felt/sheepskin, to retain the palms "Grip" on the palm rest. 1/2" Strip down the middle from left to right, usually does the trick!

To get a flat top surface, vs angled, simply stop the top print before the posts begin to appear.

Any questions or setup assistance needed, please don't hesitate to contact me here. I'll respond as quickly as I can.