I decided to turn this into a stick puppet. using a length of upholstery thread or fishing line, as well as a rubber band: pull the trigger to open or close Rex's jaws.
See it in action, and learn more about it: http://youtu.be/c9BTUQcyshs
Interesting notes on the build:
The example in the photos was printed in Ultimachine black and MakerBot yellow (creamed corn) All pieces were printed on my Replicator 2, except for the trigger, which was printed on my PrintrBot Simple to save a little time while the grip was printing on the Rep2.
Looks more yellow in the photos due to my lighting. In the video, and in person, the Creamed Corn color really does look like bone, and is a good choice for the skull.
More detailed Instructions to come, but the info here along with the video should get you up and running.
NOTES on V2 STL files:
rod-puppet_rex_v2.stl has been added; the side hole has been re-positioned to allow the mouth to close all the way. (you can always drill a small hole just above the old hole position if you have already printed the first version of the rod)
the rod end on either version may be a tight fit in the skull's socket, a little touch up to the rod end with a file or sandpaper will make it fit just right; if it is a good, snug fit, no glue is needed.
I printed all parts as oriented, with a raft: 2 shells, .2mm layer height, 10% infill. No raft was used to print the trigger and grip on my build. I normally don't use them. However, a raft is optional when printing the parts but may be beneficial when printing parts with small build plate contact areas (the skull and jaw) or may warp or lift from the plate due to length (the rod part can seriously benefit from a raft when printing).
jaw-puppet_rex-v2.stl is up, this jaw, while still loose, is designed to not fall off once the puppet is together, and it works great!
The old jaw (jaw-puppet_rex.stl) is loose fitting. if you already downloaded and printed, a needle can be heated on a candle, poked through the intersection of the joint, and a thread or piece of wire passed through the joint to secure it.
grip_2key-puppet_rex.stl is now up, and features two keyways, so the puppet can be side-triggered, or the skull can be aligned with the trigger (the traditional way)
print one of each part (Skull, jaw, rod, grip and trigger, for best results, use the latest V2 versions of the parts when applicable...excluding Puppet_Rex-assembly.stl, which is a model used for assembly reference)
assemble as in the puppetrex assembly.stl; glue the rod (if needed) into the skull, but don't forget to pass your string through the hole on the side of the rod, near the head out the bottom, tie the upper end of your line to the loop in the front of the jaw, with a double, knot. trim the excess. (hint: you can start the line in the side hole, and suck through the bottom of the tube to get the line through the rod easily, just be careful to not inhale the line!)
by using a rubber band on the top hole on the trigger, using another small fastener or some string (with the other end around the rod) it should pre-tension the trigger so orientation of the puppet isn't as important. use a 3mm screw (or a piece of 3mm filament) to attach the trigger to the grip.
The bottom end of your line line should be threaded through the passage in the top of the grip, and should be tied to the bottom-most hole on the trigger. be sure the trigger is pre-tensioned all the way, take up the slack in the line so the jaw is closed, and tie the line off. Also make sure you ream the pivot hole on the trigger, so it moves freely, without any friction.
puppet is working! so far, so good! no rubber band is needed if you bypass the trigger and pull the string directly; Gravity does the job nicely all by itself!
Added puppet_rex_stand.stl -a handy, optional display stand for your Puppet Rex! If you z-pauze at 10mm you can change the color for the text. I printed it in black with the text in yellow.; took about 1hr 15min to print. The grip fits into a socket on the stand, if it's too wobbly for your liking, a piece of tape or a small folded strip of paper will make it fit snugly.
Like it if you like it!