Newbie question - how to animate a turtle?

Hi. I am not familiar with rc but I'm hoping I might find some guidance here.
We're doing a stage play which requires a turtle or small tortoise to
remain onstage for long periods of time. For a long list of reasons (which I won't even bother to go into) we'd prefer not to use a live turtle.
However, there are distinct downsides to using a simple prop turtle made of plastic or ceramic. We an in-the-round stage and members of the audience are going to be quite close to the turtle, and, as I said, it's on the set for considerable lengths of time. If we use a simple prop, it's going to be evident to everyone in about 3 minutes that it's not real.
Our prop man thought he would be able to rig a prop turtle up with some rc stuff so that we could make it's head move (either forward and back or side to side) on command from the tech booth overlooking the stage. But, with just a few weeks before the show opens, he doesn't seem to be making any headway. He doesn't really have rc experience and, when a person starts searching the internet, there is just so much information, it's hard to know how/where to start.
We've been looking at various robotic toys, pets, etc., trying to find something that would have parts small enough to put inside our prop turtle and wouldn't have movement that was too quick for such an animal. So far, most of what we've found is too fast/powerful.
Would anyone here be able to give us some recommendations? Any help at all is greatly appreciated. Thanks.
Jennifer
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Maybe try hacking some of the Wowee type toys like seen here: http://www.wowwee.com / Depends on how big the turtle is.
As for realism, I am guessing the audience will know it's not real, no matter what you use as a "stand-in".
Just my 2 cents - JCD
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This should be a pretty easy project for anyone with RC experience -- what you want is just a couple of servos connected to the neck of the turtle. You can buy these at any hobby store, and I don't think they'd need to be particularly powerful. The whole electronics will consist of:
1. R/C transmitter -- a simple 2-channel analog one will do; this is what the prop guy up in the booth will use to control the turtle. 2. R/C receiver -- goes inside the turtle, and converts the radio waves from the transmitter to servo pulses 3. Two servos -- receive power and servo pulses, and move a little lever arm accordingly 4. Rechargable battery -- powers the receiver and servos.
The rest is whatever armature and mechanical linkages are necessary to make this thing look like a turtle with a moveable head, but I assume your prop guy can handle that part. (You could build this out of LEGO, or Erector Set, or wood, or whatever medium you like, and then cover it with a rubber or plastic turtle head/neck.
If you're getting down to the wire, it might be time to enlist some help. Your local R/C hobby store can probably put you in touch with the local R/C group; these are usually pretty active in the summer. Anybody who's built an R/C car, plane, or boat will know everything needed to make the above work, and could probably get your prop guy unstuck in a few hours.
Best, - Joe
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get a real turtle, put a fake shell over its' real shell. Hide an RC receiver, battery, and HV supply under the shell. Put electrodes from the HV supply to the feet of the turtle, and one on its' head. When you want the turtle to move, press a button on the transmitter, and it'll shock the turtle and make him move...
??
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Why does it matter if everyone knows the turtle is not real? A stage play is all make believe, none of it is real. The only important question is: Is it entertaining :)
-- jc
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I have about 40 years of experience working in theater and film, so, believe me, I know there are cases where it doesn't matter if the audience knows the prop is real or fake. Without listing a dozen examples from this show, I'll just have to ask that you trust me to have reasons for wanting the audience to question for themselves whether the turtle is real or not. Many of these have to do with some of the themes inherent in the play. And, just to go back on my word and give one concrete example, there is some business of one of the characters "feeding" his pet turtle some lettuce. If we use a very obviously fake turtle, when that moment comes, it either draws a laugh at the ludicrousness of it or it raises questions about the character's sanity. Neither are the response we're looking for at that particular moment.
Of course, the audience realizes most of our props are fakes. But, when you're playing in-the-round and the audience is sitting, literally, with their feet on the stage, the degree to which you have to try to make your fakes seem real increases. When you're dealing with live entities, the problem of suspension of disbelief becomes touchier. The next poster, RMDumse, is exactly on the same page with our thinking...we'd like the audience to assume the turtle is fake, then just throw in the tiniest bit of movement to make them doubt their opinions.
Thanks to the rest for your RC advice. We're looking to get in touch with local RC folk (which, unfortunately, seem to be a little thin on the ground in our area.)
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You might want to try a web site like www.servocity.com. I buy alot of RC stuff from them. They have transmitters, receivers, servos and all kinds of mechanical linkages. Their web has some very helpful information as well.
If you call them, they'll probably line you up with everything you need.
BRW
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I think the best of surprizes ito let everyone conclude that, and about 4 minutes in, it twitches a little. Just enough to worry them it might not be a simple prop. Like those manikins in the mall, that stand there for 10 minutes not moving, then they repose.
http://en.wikipedia.org/wiki/Suspension_of_disbelief
Just when they accept they are looking at a prop, but accept it as a turtle anyway, you reward and awe them for their disbelief.
The larger subject you are asking about is animatronics. http://en.wikipedia.org/wiki/Animatronics You might want to google on the subject with turtle and see many results. Looks like 60,000.
Looks like you might even be able to rent one already made: http://www.lifeformations.com/galleries/animals/index.htm #
-- Randy M. Dumse www.newmicros.com Caution: Objects in mirror are more confused than they appear.
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I used to work for Sight & Sound Theatres, which does very large scale biblical dramas. They use a lot of animatronic animals.
There are certainly times when a real animal on stage looks fake because it is not moving. The real animals just get used to their jobs, and don't even bother to look around at what is going on around them.
Stages can be a challenge for R/C because there are lot of radio mikes and other RF sources. An alternative is to use a purely mechanical motion, directly moved by an actor who is handling the turtle (perhaps by inserting a finger in a hole on the upstage side or underside of the turtle). It is reasonable for a turtle to simply stay inside its shell when it is placed on the floor (of course the ability to do this may depend on the play).
Sight & Sound Theatre is known for "Grand Spectacle," so they have an additional reason for animatronics. But, for most stages, I suspect it is best to avoid animatronics entirely (even if it is more fun for the technical staff).
If you want to do the animatronic turtle easily, I would suggest forgetting about the legs. Just buy any R/C car that has a steering servo. Remove the guts of the car (the wheels and drive motors are not needed). The stering servo should have an arm on it. If the head/neck of the turtle is a separate piece from the turtle, you can mount the servo inside and connect the arm of the servo to the end of the neck. Simply moving the steering on the transmitter can then move the head in and out of the shell.
Joe Dunfee
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