Thread: Closing fist prototype

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After a summer trip to CA, I got inspired by a part of the Revenge of the Mummy ride at Universal Studios Hollywood. Particularity, the part where you pass under a group of hands/arms moving/reaching down at you from the ceiling. I knew I just had to make my own for Halloween.

Despite riding it three times, I forgot to attempt to take a picture of it. I do remember that none of the hands closed a to a fist grabbing. Not to stop the creative juices.. but I decided one or two of five I have planned will do this.

This is what I've come up with so far and it's not perfected yet.

Ice maker tubing is used, with pull ties attached at the tips with bail wire. Wide 45-60 degree cuts are made where the joints are to allow bending in the correct direction. The palm is made of solid oak for strength, the finger channels are drilled out at 3/8". All lead out a single hole in the base of the forearm. The the tubes are nailed in position, small nails to allow the ties to move past freely.

The problems so far are that the ties get twisted around in the palm channels and that I'm going to need a strong motor to pull all five ties at once. Singles pull very easy otherwise.

Yes, I'm looking at motors, air would be too quick to get the creepy movement I'm looking for.

Anyways, any suggestions are welcome. Maybe I've inspired some of you to try it yourselves.. Still got 2 months.

P.S. If anyone actually has a pic of this part of the ride. I'd love to see it. Only could find one on the web during construction. No hands were in place yet.

Kool!!!!!!

Maybe the reliability of gravity would provide the pulling necesarry with a lift to reset it. Experiment with a tin can and adding sand to it, maybe a big tin can, more sand, one grain at a time..... get it just right, s l o w pull.
Balanced closely, a small motor with a lobe/cam rotating under the weight could work.
I built a teeter-tooter balanced plastic pipe large gun which was elevated via a small electric motor inside a turret on the motorcycle half-track.
Steel springs did the balancing, taking up very little space inside the turret.
I scared So Many people as they would be examining this strange machine and suddenly the 10ft. long gun barrel would go up and down!

What about a wiper motor? Pretty cheap from what I hear and you would have both the closing and opening action of the hand. I would think that you would not have to have the fingers close all the wAy, too.

My 2 cents....

Ny buddy mem22 pointed these out to me a couple of weeks ago...they are life sized and come in right and left

Wooden Articulated Hand

Here is one that has been out there awhile...probably the one you saw during construction

Simple Animatronics (robotic hand)

[ame=http://www.youtube.com/watch?v=Nbe7PgLUaUw&feature=related]YouTube - My robotic hand[/ame]

..maybe for slower closing hand you could setup a crank ghost type of system. or check out
Flying Pig for wiper motor setups

Billman, that's perfect. The fingers flex easier with those materials than what I used.

I'll post more pics after I start getting the entire prop started. Like the ride, when it's triggered, various hands reach through the roof sweeping and grabbing at anything below. Think the Army of Darkness graveyard, but from above.

Are the arms going to be animated at all?
(as in: will they be moving up and down at folks under them?)

If so, perhaps you can let the weight of the arm be the pulling force on the lines, and just concentrate on a motor to pull the arm back up.

If you run the lines from the fingertips, all the way down the length of the arm (and secure the ends to the ceiling), as the arm lowers, it should pull on the lines, and the fingers will close at the speed in which the arm lowers...perhaps that will give the "grasping from the grave" effect you want.

As for the question of a strong motor, it should not be too hard if you just run a length of fishing line from the back of the hand straight up through a small hole in the ceiling - eliminates the issue of torque by lifting at the base end of the arm, and with a cam, you can change the velocity of the lowering and raising of the arm.


May need a few motors though.

Perhaps you could construct a long repeating crank to make the arms move up and down.

Heres a link for the how to on the hand. Simple Animatronics (robotic hand)