Introduction: Dune Shai Hulud Sandworm Puppet
Time to conquer the worm. Make this Dune Shai Hulud Sandworm puppet. Sensitive to vibrations, it will emerge from beneath the sand to engulf any object or anyone within reach.
Animatronic motion based on XYZAidan's Robotic Gripper, a flexible claw device.
This puppet is approved by the Butlerian High Council. Made without electronic thinking machines or computerized 3D printing.
Step 1: Put Some Spring Into This Step...
Aidan's original robotic gripper is made from 3D printed flexible filament. I wanted to replicate the mechanism with more simple materials and see if I could craft it without the use of high tech. The wires or cord are pulled through the arms by an electronic servo motor but we are only going to manually pull it.
The Sandworm has a three section mouth so this is a variation on the 4 arm gripper design.
I used muslin as my base material. I hot glued segments of a cut up plastic straw which will act as the guide tubes for the pull cord. You need to leave some space between the straw segments so that when the cord is drawn in, the arm will naturally curl up on itself.
I used two strands of kite string as the cord to pull the arms in. I first tried some fishing line but that was too stretchy. It does take some force to pull the arms close in but I guess that also depends on how stiff the arm material is too.
So in experimentation, we need something to pull the arm back to its original flat out position when we relax the pull on the cord. I hot glued some plastic canvas on the back of the muslin to stiffen it up and provide that memory muscle to pull everything back. I suppose you could rig up some rubber bands or elastic bands or some other suitable material to bulk up the base layer.
For the main body of the sandworm, I needed a big Slinky type spring to give it the bounce and stretch of a wiggly worm. I didn't have a spring that big so I wound some stiff wire around an empty cardboard tube to form my own spring. The tube would be cut into two sections. A small part to mount the head of the sandworm and the other part to be as an internal support for the spring body.
I ran the pull cords through the body of the spring tubes. The "gripper" is hot glued to that small tube and then taped in place to the top of the spring. That lets the head of the sandworm bend over when the puppet is held upright. You have to adjust how much play is in the spring and tape it to the lower tube which is also the grip for the puppeteer.
Step 2: Bag It Up...
I sewed a fabric cover for the sandworm. You could go all out to make a silicone/latex skin.
Don't tell, but I used my electronic sewing machine. It was only on straight stitch though. I had changed the regular presser foot to a gathering foot. It didn't really scrunch up the seams like I wanted because the fabric was so thin. I was looking to get the rough sandwormy texture with the rough looking worm segments.
I just ran several seams across the piece of fabric to create the worm segments. It was then sewn into a tube to fit over the spring body. Do all of your sewing on the "wrong" or inside so you can flip things inside out to present the "good" side.
I then sewed covers that fit over the individual arms or mouth segments.
Step 3: Sink Your Teeth Into It...
I used a red magic marker to "paint" on the inside of the mouth segments. I could have used a different color fabric when I sewed the mouth segment covers but I didn't have any thin red fabric handy.
To simulate all of the crysteeth, I dabbed hot glue. I think drops of white painter's caulk or 3D fabric paint would have worked better but I didn't want to wait overnight for it to dry.
Place the mouth segment covers on taut. The individual mouth segment covers were hot glued or tacked in place only at the bottom so the cover would move free with the arm.
The body tube was pulled over the mouth segments a bit to bend them down to correct positioning. The long tube cover was hot glued or tacked in place to the mouth assembly.
Step 4: Gotta Pull Some Strings Around Here...
I think you have to experiment on how to actuate the puppet. I first had each of the three control cords tied along a single stick but keeping all lines taut didn't seem to work out. The lines still tangled up even when threaded through plastic straws as spacers. I finally just tied up each control line to a keyring to make it easier to pull. Pulling one or two rings is easy but it takes some practice to get all three in sync.
Look into animatronic tails to see the structure to make for a two stage controllable worm. You can then position the sandworm mouth in any direction for more advanced puppeteering.
So there you go, a practical special effect. Sandworms of any type, alien monsters, flesh-eating orchids, easy to build and fun to use.
P.S. If this all seems prototypey, it is. My more ambitious goal was to incorporate this into a Jack in the Box or the hidden arm that pops out of a Useless Machine. Shai Hulud automata or whirlygig? How about a Dune Shai Hulud Sandworm instead of the mechanical gripper for a Claw Machine game/prize rig. Someone should make it.