I made a chest section for the puppet out of balsa wood so that I would have something solid to hold on to while animating. Firstly I bought a block of balsa wood;
This kind of looks like I'm presenting it like it's Balsa Of Destiny, but actually it was the only angle where I could get the whole thing in clearly.
Marking out the shape of the chest section.
Here I used the Dremel to sand out a hole for the bar to fit around as well as sanding down the corner to make nice smooth edges.
Like a glove. If you wore gloves in the middle of your chest and glued them in place with Araldite. It could happen...
I also made tie-downs - I had to make my own because my puppet's feet have M3 sized holes, while the standard armature kit provides tie-downs for M4 sized holes. This turned out to be a bit of an inconvenience because apparently no shop in the world sells M3 wingnuts, so I had to order some online.