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I thought I would open a new thread rather than put this in an existing one.

Some thought that I have are;

How come everyone seems to focus on animating the skull head movements from inside the skull?

To me these movements seem unnatural as the skull does not pan/tilt like that.

Has anyone thought of external control? Why not animate the spine? make it pan and tilt rather than the head? is it because the servo is the simplest and easiest thing to use and it can only be used inside the skull.

What about the spine, I have seen this on some older Disney props. Animate the neck joints as that's what really moves when we tilt our heads. Or is the reason that its just much more complicated (and more expensive)?

Has anyone tried animating the neck?

Or is it a natural evolution of the home haunters experience......


I was thinking like threading Electrical BX wire shield (which bends like a neck) through hollowed out neck bones (this way one can also place wires through it) and then using a 3 wire system on the peripheral of the bones that would tighten to pull the neck in the direction required. or

out the wires farther out like real muscles and control them with servos or pneumatics and cover the wires with some decayed "soft tissue"
 

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I have similiar thoughts.

I considered something like this.

Actually I figured I would mount the skull on a gimbal and actuate it from down below.

As far as actually recreating real natural movement?

I am trying to figure out how you can do it.

I had a real crazy idea some time back. Use electromagnets.

Each vertebrae would have four small electromagnets. The facing surface on the adjoining vertebrae would have a small rubber magnet. The electromagnets would normally be all set with opposing pole energised. This would keep the neck straight due to the repel rule. When you want the neck to move, on the side you want to compress you change the polarity on these magnets. You could even do it in sequence so it would look natural.

Rotation is the hard part.. Likely will have to live with something occuring at the base, or inside the skull. Although the spinus process area might provide a means to achieve rotation via my crazy magnet idea. Lot of wires. For a fully functional neck with six vertebrae would be 42 wires using a common ground. I figure you could use small speaker wire, so bundle would be about 1/2 inch or so. Now the controller is another story.

I thought about cables as well. Just not sure if you pull up through openings in the vertebrae it will work.
 

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Open up and say "Aaaaahh"
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The servos are mounted inside the skull to simply hide the servos. Most people mount the skulls on Bucky skeletons where hiding mechs is virtually impossible given you can see every bone. Servos are used because they are easy to control with VSA, a visual software that syncs audio to servo motion.
 

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Hmmm...
I kinda like the concept of torso-mounted servos. The biggest obstacle would seem to be access to the chest cavity, but that could be solved by a little cutting and hingeing of the rib cage. If the Bucky is wearing any clothes (Grim Reaper, partially clothed corpse/zombie, barbershop quartet singer) then the surgery would not be noticeable. The idea of having latex or other stretchy covering over the cable sheaths to simulate tendons sounds good, too. One other thing - a "nodding" motion could be achieved by mounting on a gimbal (per spinman's suggestion) and using elastic or rubber bands to pull the skull in one direction. This would increase the load on the servo a bit, but you now have room for larger motors. Tilt could be done the same way, with a longer servo horn to increase the range of motion. Rotation would probably still be done via an inside-the-skull servo. I'd use Nitinol wire for the cables. Very flexible and durable, and not too expensive.
Damn...another challenge.
 

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Jaw and eyes still inside.

I think controlling the skull externally is very doable. I plan on starting a small test project to make a simple articulated neck. Rotation is the tough one.

That being said, I think a servo or actuator of some sort will need to remain in the skull. This goes for the eyes if animated as well.

To control the nod and tilt function, I think it can be done from below with cables. As far as rotation, there is not reason the servo's could not be mounted on a rotating platform.
 

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I just assumed that the servos were placed in side the skull because of the steel bar that runs through the spine. If you take that out your skeleton will slump over, unless of course you have something stronger then servos controlling it. (Buckys are very heavy and place alot of demand on the servos... this is why when placing the servo plate on the rod, you want to get the center of gravity just right.
 

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I need a neck.

I have plenty of the skulls Doc used. I need neck vertebrae. I would prefer to not buy an entire bucky.

Anyone have any ideas?
 

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For my Kmart skulls, I was planning on making my spine ... 1 vertebrae at a time out of sculptamold (bought from AC Moore) .. its a paper mache/plaster product... fast drying time and really light.
 

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Servos are used inside the skull for many reasons. This is not to say that no one should be thinking outside the box (or outside the skull), but here are some of the issues:

1. Weight. The skull is relatively light, but bucky skulls are pushing the limits of affordable servos, so we try not to add much more weight. Even if the weight was the same, moving it from below would require more toruqe from the servos because of the leverage involved.

2. Concealment. This one is obvious. All the controls and wiring can be hidden inside the skull

3. Cost. If you start playing with other controls besides servos or try to make electromagnets for this project, you will probably be spending more than just buying servos.

4. Compatability. Almost everyone is using VSA software which controls servos. It seems to be the best solution out there for syncronized audio and servo movements and also relay control and DMX. You could develop something else, but why re-invent the wheel? VSA is also pretty inexpensive.


Admittedly, the movements of the 3 axis skull are not 100% anitomically correct. The pivot point on a human head is lower in the neck, not up inside the skull, but the rod end which is being used as a gimbal is pretty low in the skull giving us a pretty good trade-off. All the points above are covered and the motion is pretty convincing unless you just got out of medical school.

I am interested in seeing what comes out of this thread, and don't mean to discourage this sort of development at all. I am just pointing out why it has been done the way it has been done so far.

It's people with vision that make great new things happen, so by all means, keep up the good work.
 

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Likes th' idea o' bycycle cables fer movement I does, an' no ones way is set in stone jus' 'ow ta make th' 'ead move, so as our most learned professor HB said, go a'ead an' nvent '/design th' better mouse trap.. who knows, it' jus' might be 2009's Project o' the Year!

Whic' brings up an' idea..

Capt. Jack
 

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Nice work.

Helps to have the right equipment to machine stuff huh!

His design is exactly one concept I thought of. Not quite as sophisticated of course. Mine being less. LOL !!

I think I see a very thin servo between the universal/gimbal and the aluminum plate I suspect he intends to mount eye movement too. (edit) Uh no it is a pulley. Had to enlarge the pic to see it. Not sure how he is going to rotate.

I don't see a jaw. Or a moveable one. ( edit ) I saw further in post he mentions jaw movement.

Now as far as the haunters here, I suspect objections will be posted, because one would have to find a way to hide the apparatus in the case of a skeltal prop.

This is why I am gravitating toward the other tail solution. Hiding very fine cable through holes in the neck vertebrae is easy to do. Now to control a head mounted on top of a neck of this design will likely require larger servo's. Since I will mount the servo's below this will not pose a problem. I intend to offer rotation from the base and mount nor and tilt servos on the rotating base.

My prop will be the graveyard type. I am hoping to use pneumatics to raise the skulls up from behind tombstones.

A dialogue between the skulls regarding missing parts, and then a rendition of " I AINT GOT NO BODY "

I just scored some more pneumatics on ebay. Picked up a Humphrey 10 valve 24 volt manifold. I suspect this will have limited use, but I only paid $11.00 including shipoping. Also picked up a hi volume filter for $12.00 including shipping. And 10 flow control valves 1/4 by 1/4 with one fitting being the plastic compression type for $36.00.
 
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