Final (ish) design. Fully functional at this point. Still to do:
* add a ledge with a bit of cushioning on the front of the torso cutout. Turns out out full cushioning is not needed. Just a small portion to keep her plate from sliding towards her.
* Add bumpers to the rear corners to protect the back cushion
Anyway pics of the final design are attached. Tray DXF was designed in Fusion 360 and laser cut from 6mm acrylic.
-Some way to attach to the wheelchair (used the four slots to run webbing through with buckle clips). There are trim pieces, Fusion 360’s assemble was giving me grief.
-Cup holder – Couldn’t find a commercial one the right size and 3d printing something to hold potentially hot/heavy liquids didn’t seem like a good idea. Ordered a commercial one and printed an insert to make it the right size. Also had to add a depth ring so it wouldn’t hit her thigh.
-Edging to keep things from falling off – Nothing I could find commercially so designed an F channel that friction fits. (small pieces of dbl sided tape keeps everything from slipping.)
-Had to hold a laptop- Yikes! The tray is only attached at the armrests, front was completely unsupported. So-figured out how to design hirth joints so they could swing down and dowels could rest against the foot rests of the chair. The tray portions of the joints are designed with an F channel to attach to the tray. Would have preferred they swing front to back for added strength but they would get in the way of her torso on one side and the cup holder on the other. Tested and very solid. Particularly proud of that implementation.
-My own criteria was that nothing should be permanently attached to the tray to allow for design changes. Acrylic is expensive so did not want to damage it.
![cup holder adjuster|666×500](upload://x9SeaUI878fSPGUN8aHSUqUdZkk.png) ![tray assembled|666×500](upload://dibkCicFEquKumV6cfCtQzwT7Wg.png) ![tray underside|666×500](upload://jzd6KBJJgUMK7IVR92XJvpeZGwn.png)