From: FrryFox
Subject: Re: FL: FL : TL: Looking for source of “bearings”

Hardware store.

The “rings” you can find in the plumbing department (although they are grooved on the inside, because they are the fasteners for water pipes… like those on your toilet and sink). Use a dremel to widen the ring to allow more of the “ball” through. You can also thread piping into the rings to make extensions so the tail isn’t 100% rings and balls. (for a 30” tail, that would be a lot of hardware).

Or flat washers if you don’t want the collar and literally just want a “ring”. Check the nuts and bolts section.

For the “balls”, check a local plastics store (same place you would look for Delrin). The one near me sells Delrin balls in a few different diameters. Although steel would be better for the long run, it might be too heavy.

Or for S&G’s you could just use Universal joints… generally available in the hardware section of the store near the sockets. Craftsman’s will run about $7 a joint… no-name brands… 3 for $2.99. And they work just as well. The UV’s are made for sockets and have a (usually) 1/2” square male and female connector for chaining them together.

Rymeer and I chatted once about making a tail from wood or plastic using hand made 2-D joints in alternating pattern so half of them would allow (if hanging down) left/right motion, the other half fore/backward motion. If made a few of the joints from a wooden closet rod with graphite lubricated Delrin “pin” and chained them together and it seemed to work decently but I never finished the entire tail (mainly because i’ve been concentrating on refining my head piece skills). The advantage of this design is extreme low-cost compared to buying the joints. Disadvantage is the labor. Without my router table and jigsaw it would take well over an hour per joint, as is, it takes about 15-20 mins.

From: SkyLioness
I am looking for a source of those ball and ring things that roll on deodorants bottles use. They are good to use to make ball-joint eye movements and blinking etc for puppets and so on.

Something that just played over in my mind: Why even if you had enough to line up and drill and fit would make a wonderful swishing-in-any-direction tail. Mount the outside ring of the first ball to a butt plate, then drill a hole in the ball insert a rod that will lead to the other ring and mount it to that ring; then drill a hole in that ball and insert a rod and lead to the other ring and mount it to that ring and so on. Metal ball joints may be to heavy for use for a tail. Something like this,

\\ 
\\ 

O is the ball inside the ring,

= is the rod inserted into the drilled ball and attached to the next ring (repeat)

single unit looks like:

beware, ascii art follows:

 ||
 || |O=|O=|O=|O=|O=|O=|O=|O= 
 ||

This thing would have maximum flex to it, and would be fairly tough enough to stand serious abuse if put together right. Discs of a closed cell foam cut into rings can build up the diameter of the tail. This can be rigged with cable pulls to move it, curl it, whatever is needed. Elastic band such as elastic cord can be used like wise to give it a slight curl.

If anyone uses this plan all I ask is that you give me credit for coming up with it and you may use it freely. Thanks.

Anyway:

Anyone know were a ‘clean’ hopefully _unused_ source can be located?

From: FrryFox
Subject: FL: Tails in motion….

The single most irritating problem I’ve continually run into when trying to add motion to a tail is center of gravity(COG). The tail will, by gravity, try to hang down from the point at which it contacts the wearer unless some other force acts on it. The three pendulum concept is very valid (the motion is quite chaotic, dampening the motion is almost required), but the tail would hang straight down hitting the wearers legs whenever in motion.

The simple solution is to add a fixed spacer from the harness out away from the body so some curvature inward (toward the wearer) can be added and then curvature away from the wearer. With out the inward curve first the tail will naturally hang down again (ie find its COG). The problem lies in sitting down with said fixed spacer attached and/or an unexpected fall on your rear.

Another simple solution is to use malleable structure. Windancer’s tail is 2 9gauge wires. The wire is strong enough to give permanent form but it bounces around back there quite a bit when I’m moving. It also collapses nicely when its unexpectedly fell upon. PandaGuy’s comment is it looked like a “Pikachu” tail, but better to have to rebend it than have it surgically removed from my back.

Getting more complex…. Springs and counter-weights. Which is way too bulky and cumbersome for my liking. Multiple springs provide stability and motion. The counter weights provide the dampening and initial form of the tail…….

Hmmm.. This just occurred to me… Garage springs. To those of you with automatic garage doors, these are thick 2 inch diameter coiled springs made of about 8 gauge equivalent galvanized steel. Not sure on the cost, but they would have excellent motion properties (since the entire tail would be a spring). A solid (belted to the wearer) harness would allow for a intricately formed tail that with a little care would be able to defy the COG because of the springs properties….. damn. I had other plans for this week now I’m going to be in the workshop every night seeing how viable this is… I think ill shut up now and go back to the office.

From: Elan Ruskin

For the tail mostly tip flicking (feline suit) and maybe a bit of casual movement. There’s a remarkably simple and mechanical way to get an interesting range of movement, if anyone here can figure out a way to work it into a tail: a multiweight pendulum. The basic idea is that you take one rod, weighted more heavily at one end than the other, and attach its center of mass to one end of another rod with a ball-and-socket joint (free motion). Now you take this second rod, counterweight its other end so as to balance out the entire first rod (as well as its own weight), and fulcrum it to a still third rod, and you can of course iterate this as long as you like. If everything’s counterweighted properly, it should hang in equilibrium until the slightest force acts on any part of the system, at which point it all starts swinging around in a rather lively manner. Now, all this makes a very pretty sculpture, but I myself haven’t quite been able to work out how to make it curve like a tail. If one of you can do it, though, it’s a neat and cheap (and zero-electronics) way to add some movement.

From: WolfTail
Subj: Wolf tail creation

Every wolf needs a tail right? I could not find anyone making animatronic tails, so I decided to fill that void…

A web photo gallery displaying all the pics taken during construction is here: http://www.wolftronix.com/tail/

- thick wire, 9 gauge
- batting/polyfill
- plastic strapping
- upholstery roping
- feathered tails