So, last year a neighbor was throwing out a wheelchair - nothing wrong with it. I grabbed it up knowing I wanted to use it for a scare I could roam the neighborhood with.
I took off the back (6 screws) and replaced it with a wooden platform for the scissor jack. I used steel L frame on base and two pieces bolted together for holding the scissor jack. U-bolts around the chairs arms hold the bottom and top (top U-bolts not in this picture)
After getting it to work, I redesigned the foot connector ...
Here it is when sprung...
Front view when sprung...noticed I did disconnect the hips from the spine...was worried about it being too heavy.
This could easily be transformed into a pneumatic prop, removing the pvc foot trigger and building a 'floor' for adding a tank for air (I thought a tank could be disguised as an oxygen tank for poor old skelly) and a cylinder to spring it.
Hopefully, I'll dress up the skeleton as Aunt Libby, where she will look sickly but normal, and then spring it to show bones underneath. If I do, I'll update this thread.