# EXTREME Prototype- Animated arms and head prop



## drzeus (Jun 25, 2011)

I've never seen this linkage although I would imagine someone has done it before.
Last night I animated the moving head for my "Frankenstein" lifesize, then I decided I was going to animate the arms as well.
Utilizing the motion of the central pipe, I devised a method of raising /lowering the arms as well.
This is in VERY EARLY development, and I'm pretty certain the motor doesn't have enuff torque to raise the foam forearms (not shown) of the creature as they are quite heavy. Although, the alternate raising of the arms may assist the mechanism somewhat acting as a counterweight to some degree.
Any ideas/ Thoughts?
What motor would you suggest? (I'm on a tight budget).
What armature would work better raising and lowering the arms (or am I simply on the wrong track here?).
You guys are the best. Throw me a bone OK?!!

Thanx!
DrZeus

2011-07-25_20-46-27_809.mp4 video by Terry_Myers - Photobucket


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## RoxyBlue (Oct 6, 2008)

I think this is a very clever approach to animating both head and arms on a prop - no lines to run (or break). I suspect you may be right about weight being an issue. Have you tried running it yet with some weight on the arms?


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## niblique71 (Dec 2, 2009)

In the video, it looks like you're mechanism is fairly well balanced. If you maintain that balance you could probably add even more weight to both arms as long as the weight is equal. As you add more weight, you'll want to make sure that you have some lube on the moving joints especially your arm actuators since they do slide a little. The friction will increase with weight. At some point you could exceed the strength of your PVC, but I think you're on the right track.


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## drzeus (Jun 25, 2011)

Yep.
Just added the Foam arms. Complete failure.
Motor freezes as its raising the arms. Might be a timing (balance) issue.
You guys are Dr Frankensteins in your own right.
Appreciate the input!
Keep the thoughts coming please!
This will work with your help!


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## niblique71 (Dec 2, 2009)

I suspect it's friction rather than weight that is causing your failure. Did you try adding lube to the arm actuators?? How about lube on the shoulder joints??

A video or pic of the prop with the arms attached might help one of us to get you on your way. But keep in mind you still have to add covering (fabric?) and other "Drag" inducing items to your prop. You might have to go with a stronger motor. But I'd keep experimenting. I still say that with the right tweaking you might have a successful prop on your hands.


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## drzeus (Jun 25, 2011)

Thanks for the help niblique.
You could very well be right about friction.
I'll try to get another vid uploaded after work today.today


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## Daphne (Oct 18, 2006)

This is a neat design. Please keep us updated. If anyone can help you come up with a solution, it is this bunch!


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## SuperCreep31 (Nov 22, 2009)

if you want both arms to move up and down at the same time maybe you could connect the 2 pieces being pushed in the middle and then add a spring to take some of the load off the motor? That was just my first thought... maybe worth a try.


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## Hallomarine (Jul 16, 2011)

SINCE you didn't have the forearms on, we couldn't see how the motor will react. My thought is this: clothing will cause friction on the arm movements also. A wiper motor may give you more torque to over come that. I'm looking at Super Creeps idea. Any springs may cause more initial resistance, but would definitely help with the return. Good luck and keep us posted. You're off to a great start. HM


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## TheOneAndOnlyKelly (May 7, 2009)

You might also look at adding counterweights on the back of the shoulders (Possibly hanging down) to balance the load. I'd experiement that way as well. Anything to help reduce the load on the motor.


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## The_Caretaker (Mar 6, 2007)

The counter weight should work, it might be best to use the motor to return the arm back to its starting point it will run at an even pace that way, also you won't have to rely on gravity to return it.


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## RoxyBlue (Oct 6, 2008)

What type of motor are you currently using, BTW? It looks like a vent motor (4RPM gearmotor), but hard to tell.

Another approach to consider if you have the time is to try this out on a smaller scale with lighter weight materials. If you're using regular PVC pipe, try making a framework out of the type called "hot and cold". It's thinner walled and would therefore be a bit lighter in weight.


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## drzeus (Jun 25, 2011)

Thanx guys.
Sorry I haven't gotten around to doing much more with the prop yet. Its just standing in the family room (the wifes thrilled!). Im a tad ocd and have gotten distracted by another prop. I will post progress soon...
Yes, this is a vent motor. Can't beat a $3 motor! I bought a bunch of em and hope to make use of every one.
Roxy, is the "hot and cold" pipe your referring to called "pex " pipe? I just picked some of it up at menards. Its colored either red or blue. The stuff I bought is pretty flexible. You're probably speaking of something else?


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## RoxyBlue (Oct 6, 2008)

The pipe I was referring to is called CPVC. I got it at either Lowe's or Home Dept, and it's whitish in color. It's not flexible the way pex pipe is.


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## drzeus (Jun 25, 2011)

K. I'll check it out Roxy.
Thanks for your input.
I'll keep you posted on the progress...


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## drzeus (Jun 25, 2011)

Thanks for all the assistance.
I'm a long way from getting this functional but you've all sparked some normally non-functional synapses.
As a typical haunter, I never throw ANYTHING away. I've been holding on to our sons used roller blade bearings for 15 years- dug em out, and guess what? They might work! 
The bearings are inserted (with slight modification) in to a 3/4 to 1/2 pvc adapter.
Gonna require some reworking of the arm structure, but...
Give me your ideas please (and thanks for the bones!)


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## RoxyBlue (Oct 6, 2008)

I'd say go for it. This is, after all, a prototype, so experimentation comes with the territory

Anything that will reduce drag should help.


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