Here is a front elevation draft of our skeleton that will be made out of a combination of steel and aluminum to achieve a very durable, professional grade animatronic while keeping the weight down to reasonable levels. Not illustrated here is the upper section (that will be horizontal during use) of the leg which will be be 25 1/2" long and is listed on the Skeleton Parts List shown below. The strange looking ribcage assembly has been designed to have a hand drill mounted to it that will spin a weighted cam that will cause the body to shake as mild or violently as we desire based on the speed of the drill and weight of the cam. Although I have never actually used anything like this before I am confident that it will work and have decided to build the entire skeleton before doing an actual test run. Using the parts cut out list and the two elevations here, you should have no problem getting all your parts ready for assembly which we will be moving on to next. Even though I own a welder and could easily weld the joints on our skeleton rather than using bolts and locknuts, I chose to use the bolts instead so that those of you wishing to build your own who may not have a welder would still be able to take on this project.

   I have an idea of how to create the leg joints for our fit throwing baby and will be going first to that element just to get it established and make sure it is going to work the way I am hoping. Using 1" square 1/8" wall steel tubing (don't ask me why the steel industry calls square shaped steel "tubing", as I still can't figure it out myself) Starting with the upper leg section at the "knee" I measure back from the end 1 1/2" and then using a die cutter, slot one surface back to create a clean rectangular opening. Be sure to clean up the edges well with a file and sandpaper smooth for a long wearing joint. Next I place the top of the lower leg that will be the other half of the knee into a steel vise approximately 1" and slightly crush it just enough to slip inside of the upper knee slot. If you look closely you can see the lower pipe end just fits inside the slot to fully cover. Since my dummy will be fitted with a foam rubber body, I don't want the knees tearing up the foam inside when he stomps his feet. The cover here should all but eliminate it from eating the body.  Now I will round the bottom edges of the slotted end and attach the knee together using a hinge pin made with 3/8" steel rod that has been drilled out on each end  for the hitch pins that will keep it together. Make sure to measure accurately before drilling the holes to just clear the space of the pipe plus a washer on each side. This will keep the leg from flopping side to side when activated. My hopes were that this joint would keep the lower leg from moving very far outward during use, as I need his feet to hit the floor at a certain spot on the pedestal to create the illusion of an authentic movement. Conversely I also didn't want the lower legs to bend backwards very far either, as this could allow the shoes to get caught under the edge of the seat box. The limited movement of this joint turned out to work perfectly for my needs on this prop, so I simply created the same type of joint at the bottom of the lower leg to function the same way for the ankles.  

   Once I had the knees and ankles working I laid them side by side, feet pointing down and separated them the overall width apart that they will be once attached (11" between). This was not shown in the elevation draft due to my trying to keep the time investment down on this project, but it will be covered here clear enough to hopefully answer all the questions you might have. (***IMPORTANT NOTE***; I would not use these same dimensions on a second dummy for this project! I am showing here all of the documentation it took for me to make my project and how I did it, but I decided once this was completed that one thing that would benefit from change next time would be less distance between the legs. So if you shorten the leg assembly braces from the 13" shown here to 11" you may be a little happier with your completed prop***) The piece you see laid across the back of the upper leg is the first of two 13" leg assembly braces I used to keep both of his legs parallel to each other during operation. The pipe clamp is there so when I drill the holes at the joints for attachment the pieces can't migrate and cause the assembly to be out of the tolerances I will need for the animations to work. In this shot you see the 1/4" hole I have drilled has been squared off using a small elliptical file, allowing me to use a 2 1/2" carriage bolt as shown. On the bottom of the lower piece I will use a split washer and a lock nut. This photo is jumping ahead a bit, but it shows you what the underneath side of the leg assembly will look like at the back. The second leg brace is spaced 3" away from the one on the end. Be sure to measure down the legs to be sure they are square and parallel before drilling your holes. Before this assembly is complete we will need to mount the cylinder clevis and drill holes in the horizontal leg sections for our 1/2" pivot rod. Measure 7" from the back of the leg assembly and mark on center to drill the 1/2" hole in each side. The brackets you see here attached to the pivot rod will be covered in the next few steps.