I am not the first on the list to do this, but this is my version. I made a L shaped bracket out of 1 inch PVC pipe and an 90 degree ell. I
drilled a hole through the ell for a pivot rod, which is bolted to the bottom of the casket using a pair or U-bolts. Bucky's tailbone sits in a
hole in the PVC and his neck is strapped to the end of the pipe. I removed the pins that attach his legs to the pelvis, and replace them
with small bungy cords. This gave him a lot more flexibility. The air cylinder is attached between the PCV bracket and the bottom of the
casket. The cylinder is attached to a 3-way solenoid. When the solenoid  is activated air is let into the cylinder making Bucky sit up. When the
solenoid is deactivated, the air from the cylinder is vented through a needle valve which controls the speed at which Bucky lays down, so Bucky
does not slam back into the casket.