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 Here is our first look at the items making up the entire frame and
mechanism together. We attached the lower points of the scissor sections to each
other using 1/4" x 1 1/2" hex bolts. Cut your lower square tube down
to 47" long and now drill a 1/4" hole in the bottom side. Drill the
same hole in each of your other two sections as well. Remember to put these on
center and 3/8" from the ends. Then drill one final hole in the angle
aluminum exactly 4" above the one in the end. Measure this on center from
the other hole. Attachment will be bolt with flat washer through square
tube / flat washer / angle aluminum / flat washer / lock nut. Do not fully
tighten this connection, as the scissors need some slack to move, but it does
need to be snug to prevent slop.
You will need to pre drill your holes for attaching the sides
together, drill your pin holes for the cylinder and drill the holes at the end of the
sides at the bottom to attach your foot's extension. You will be gluing the 1
5/8" plywood brace or divider between the the two side to just ONE SIDE of
the frame using six 1 1/4" drywall screws. This frame will be
disassemble-able in the event we ever need to replace the air ram. Flush
the brace up with the top of the uprights and to the back. This will give us a
cavity between the two sides for the air cylinder to rest partially inside of.
 The
extension's top hole needs to be
placed in exactly the same spot as
the bottom hole so the extension
can be taken off, turned around and
bolted back into place the opposite
way to shorten the footprint and
store the extension.
 Once you have all your holes drilled and then attach the final side to your
framework with 1 1/4" drywall screws and the 5/16" carriage bolts,
your air cylinder should be "floating" between the two sides. The placement
of the holes for the pin are a "one shot" type situation. If they
aren't perfectly placed your cylinder will be lopsided. To ensure that mine were
right I measured at least twice and then used a tapered drill bit to predrill
the holes. A tapered bit has a pinpoint to it that tapers back up to like a #8
body. That means it will enter at a precise point and will not wander as it
travels through the wood like a regular bit will do following the softer grain.
 With both sides on next stand up the frame and use a square to make sure it
is vertical. Then using 1 1/4" drywall screws, attach the stabilizer to the
back at the floor. Notice the screws are centered to each of the 3/4"
sides. Here's a little trick when doing scroll work like shown above; once you
have drawn a shape that looks right to you and is centering the middle section
for its attachment, cut out one side with your jig or scroll saw in one piece
and use that off fall as a template for the other side. Both sides will then be
exactly alike.
As soon as I tested the mechanism I learned that when the air cylinder fully
 deploys, it tilts out forward slightly, putting a
 bind on the cylinder sliding back
down into the body of the pump. To counter this I used a hose clamp around the
top of the pump's cap to hold one end of a small chain that limited the pump to
perfectly aligned to the ram. No binding has
occured since.
Success! The mechanism for our
exorcist is now together! We will
be hooking air up to it later, but
for now we need to turn to our
puppet. We'll call her Regan. |
