|
Ages ago, there were plastic, posable dolls. Inside was a couple of rubberbands that kept their arms and
legs together with the body.
This is what is the basis for this armature for a dummy. Only on a much larger scale... lifesize.
By threading the bungee cords through the right pieces, the bungee cord creates a "pressure" that holds
the pieces together.
There are three bungee cords used in the armature. One runs between the "wrists", up the arms and through
the shoulders.
Another runs from the ackles up the legs and through the hips.
A third rund from the neck down to the hips.
To freeze the elbows and knees into a position, a bolt is run through the back-to-back PVC elbows, and is
tightened down with wing nuts, to make the joint nearly immovable. They can always be loosened again for repositioning.
I actually created one of these for a christmas display. It wound up inside a Santa Clause, which was bent
on one knee in front of our manger nativity scene. The dummy santa was able to stay virtical, and only needed to be anchored
to a spiral stake in the ground because we feared vandals might walk off with him.
I did use foam rubber to give it demention, but depending on the character that the armature is being used
for, foam rubber is an option.
The bungee cords threaded through the PVC is in green.
The bolts that freeze the shoulders, elbows, hips, knees and ankles are in red.
You MIGHT need to run a bolt across the shoulders & hips. In that case, they don't actually
sell "bolts" that are THAT long. You'll need to pick up 1/4-20 ALLTHREAD to make a bolt yourself. All Thread is a rod that
is threaded. You can cut it to the desired length as needed. Be sure to add an extra inch or so, so that the threaded rod
is long enough to pass through the elbows.
All elbows that are back-to-back need to have a very shorth length of PVC pipe between them. This should
be about 1 1/2" to 2". You want to be sure that the elbows are actually touching, with NO pipe exposed
at the joint between them. This is NOT to be a tightly fitted connection, you want the pipe to float "freely" between
the elbows.
If the pipe is cut too long, it will wedge itself into the elbows and make it very difficult to position
the fittings. About a 1/4" short will prevent the pipe from wedging into at least one of the fittings, thusly, ensuring that
the armature remains loose and easily adjustable.
Remember, the bolts and wing nuts are going to be the way the joints are made unmoveable.
The bungee cords keep the joints that are NOT bolted... together. When the armature is positioned, with
clothes and possibly foam rubber, you don't want the fittings falling apart after the foam rubber and clothing are covering
them. Repositioning and lining up pipe to fittings with the weight of the foam and clothing is a tremendous
pain in the tail.
The bungees keep a "tension" that holds everything together. Do not glue any parts together!
Doing so will cause the adjustability of the glued joint to be lost.
Cutting the PVC to proper length...
PVC can be cut shorter, but it's tough to add MORE PVC if the cut is too short. Also, consider the clothing
you're using. Is the clothing YOUR size? If so, you can measure your bones to make the armature your size.
After a bit of trial & error on my project. I discovered that if you simply subtract an inch for each
"bone-to-pipe" measurement, it'll turn out perfectly. Nothing's worse than seeing your clothes on a prop that's too tall or
the arms too long for the costume.
Unless you really want to create a frankenstien, with flooders and sleeve cuffs that end up at the elbows.
As you cut the pipe, you have to make two of each. A left & a right. I found it easier to take all the
measurements and write them down on a small diagram of the armature. (with an arrow pointing to the armature section that
the measuement was ment for.
After all the measurements are taken, proceed to cutting the lengths. two of each. I even went as far as
labeling each piece with a marker, (Upper Arm, fore arm, thigh, calf, foot, shoulder,) it's easy to get them mixed up.
Oh yeah... Don't forget those short bits for between the PVC elbow fittings.
Once all the PVC has been cut, you'll want to "TEST FIT" everything, to see how it measures up. Sometimes
it helps to lay out the cloths, flat on a floor or a table, and see if the joints are positioned properly. Checking to see
if the knees and elbows are going to "bend" in the right places.
If anything is obviously too long, then hack a bit more off. If anything is too short, well, you'll need
to cut a new length. Put the "too-short pieces" off to the side, so it doesn't accidentally "find it's way" back into the
project.
Drilling holes in the PVC Elbows...
This isn't a "tough" proceedure, but it is a bit tricky. The best way that I can come up with is a little
trick using a marker and a long pencil.
Using the pencil as a representation of the bolt that will pass through the elbows, you can position the
pencil on the elbows, (with the short piece between them,) as the PVC elbows lay flat on a table.
Steel bolts are nutorious for their "inflexability" so it's important that the pencil is laid on top of
the PVC elbow assembly, in such a manner, that the pencil passes through the assembly without it touching the inide walls
of the elbows. In other words, "cenerted".
You can then, center up a mark on the elbows, (the mark will be on the curved part of the elbow.) and may
seem a bit off, visually. You can then drill the holes in the PVC elbows, where the bolt is to pass through.
Test out your first set of drilled elbows to make sure the holes are properly located. This will help you
to position the holes correctly in the next sets of elbows as you work things out.
After the elbows, knees and ankle joints are drilled out, you'll have a pretty decent idea where the holes
go for the hips and shoulders.
While the drill is all warmed up, you'll need to make anchor points for the bungee cords to be anchored
to. These are simply holes at the tip of the feet, at the end of the arms, a hole in the back of the PVC T-fitting, (so that
the cord passes through the back wall of the fitting,) and at the end of the pipe used for a neck.
Once the elbows are drilled and they have all been tested to see if they'll work out right, take the pieces
apart and lay the pieces out, in roughly the way that they'll be assembled. Take all the bolts out, because the next thing
you'll be doing is threading the bungee cords through the pieces.
Threading the Bungee Cords...
Let's start off at the feet. The bungee cord will be threaded up one leg, across the hips and down the other
leg. Each end of the bungee cord is threaded through a hole at the toe end of the feet. Slip the cord through and tigh a decent
knot in the end of the cord. Bungee cord knots are prone to slip out, so it may be a good idea to Hot Melt glue to the fibers
of the knot, to help prevent the knot from slipping out. A good measure of successfull bungee knotting is to leave a few inches
of cord PAST the knot. The knots MAY slip a little, but this is normal.
Once the bungee cord is threaded through the PVC peices, you can assemble the pieces and insert the bolts
(washers behind the wing nuts) & all-thread through the holes and leave them loosely tightened. Tull out a bit of
the bungee cord, so as to create a somewhat strong tension. It should be strong enough to make it a little difficult for the
pipe to pull free of the PVC elbow fittings. Once the tention is set, use the vice grips to clamp & hold the bungee cord
firmly. (You did thread the cord through the hole first, right?)
The Vice Grips are usually adjusted by a knob at the end of the larger handle. Rotating this knob one way
will tighten the grip the jaws have, while the opposite holds true in rotating it the other way. Usually, when the gip is
being adjusted, (and you're close to the setting you want for it's "grip", a slight turn is all you really need.
You can then tie another firm knot in the cord right up next to the vice grips. Then drizzle a glob of hot
melt glue over the knot in the bungee to help hold the knot. Once it has cooled completely, you can unlock the vice grips,
by squeezing the tiny "inside third" handle towards the big handle. Carefull at the grips will spring open with a jump-like
action.
Check out the knots. Is there any evidence that they are slipping out?
The legs and hips are together, with the bolts and allthread, with washers to prevent the wing nuts from
"digging into" the PVC elbows. Try to adjust and position the legs, bend the feet flat to the floor, so that the legs are
standing virtically, (and leaning forward slightly.) It should stand on it's own.
If the knee bolts are loose, you can bend the knees, then, tighten up the bolts and they should be fairly
difficult to move from their position. You can move the legs in relationship to the hips as well. Tighten the hips. They should
remain firmly positioned.
Now, it's time to move on to the arms and shoulders. With exception of the elbows and the slight differences
in pipe length, the arms and shoulders are assembled in much the same way, tying a knot in the bungee, threading through the
holes, pipe and elbows, tentioning the bungee cord, placing the vice grip to hold the tension and applying the hot melt glue
to the knots to keep them from slipping. Cut the cord so a few inches is left after the knot. Even if the knot slips, it's
only a little slippage. Again this is normal for a bungee cord.
The neck, back and hips are a simpler assembly. Most of the tough stuff is over. Hopefully you have enough
cord left to thread through the hole drilled into the pipe for the neck, down the neck, through the PVC Cross Piece, down
the "spine" and through the T-fitting and straight through the hole in the back wall of the T. You won't have much to pull
through here, but it still needs that tension. Be sure to knot the cord and use the holt melt glue to help hold the knot.
Leaving a few inches for a bit of slipping.
The armature is complete.
Go ahead and try to adjust the armature into various positions. Try to position the figure to sit in
a chair, with it's leg crossed over a knee. See if it'll sit on the ground with it's arms propped up behind itself. Stand
him upright and ajust the knees, elbows, ankles and shoulders. Twist the torso at the hips and shoulders, Totate the arms
at the shoulders, rotate the legs at the hips, bend the legs at the hips. See if you can get it to balance on one leg.
See if you can get it to balance on no legs... (Uh, well, maybe not.) But it's pretty flexable. And
you can freeze most of the joints so that he doesn't move all that much.
~~~~~~~~~~~~~~~~~~~~~
Please be sure to visit "How to Halloween" A new up and coming site on building your own Halloween decorations for next to
nil!
The Halloween-L is a great website & forum. You should go there NOW! Ok, after you view my website. But right after that,
go there! (If you know what's "Boo" for you!)
|
