Bourno's How-To Build a Skelerector Page
Page 1 - Introduction Page
Page 2 - Front Bar Assemblies and Rotating Bar
Page 3 - Rear Bar Assembly
Page 4 - Lifting Bar and its Assembly
Page 5 - Base Frame
Page 6 - Putting all the pieces together
Page 7 - Pneumatics and the skeleton
Page 6 - Putting all the pieces together
Cylinder mounts - 3" of 1" square tubing (drill hole as required for cylinder end)
3/8" bolts at lengths 2-1/2", 3-1/2", 4-1/2"
3/8" washers
Assembly Pictures
Here is a homemade clevis.  I used the proper sized
nut that fits the air cylinder threads and then welded
on a couple of washers.

Use whatever works best for you.
Here is my air cylinder with its clevis being bolted to
the rear bar assembly.
Before welding the rear pivot of the air cylinder,
make sure the 4-bar is all put together as shown
below with the front arms resting on the stop pieces
and the 5" stroke air cylinder retracted all the way.
Manually test the mechanism
to see if it works and moves
The 2-1/2" bolts go into the rotating bar.  You may need a
washer or two to take out any excess play.