After some weeks of CAD and prototypes I've got something working after spending most of yesterday doing building and soldering and coding.
This is the base, 3D printed in PLA, version 20 billion or something. I have a box full of nearly identical ones now but this one is lighter than the others with holes and clips in useful places.
The wheels are also 3D printed with sections of bicycle inner tube for tyres. They don't have axles - the protruding inner rims sit in recesses in the body shell so there's less strain on the servos in case of impact. In theory.
The flipper mechanism with its servo already in place.
And this abomination of soldering is the electronics. There's an Arduino Mini Pro, a 433Mhz radio receiver, a 5V voltage regulator, a connector block for up to 4 servos and a battery connector. Getting the radio to work took several minutes of programming (by which I mean hours) but all good fun.
And it does actually all fit together. First off the 2 cell LiPo battery slots in under the drive servo casing whilst the servos and attached wheels go inside it.
The flipper mechanism is bolted onto the weapons platform using the access holes I stupidly forgot to include in previous versions.
And the electronics bend around 90 degrees to fit in the remaining gap.
The lid holds everything in. The drop-down bits rest just about the drive servos so they can't jump out of their housings. They also hold the electronics in place laterally. No screws or bolts; it clips in securely. Theory again there.
Aside from the excess of servo lead it's done. Maybe the lid could do with coming forward and down a little more though.
And it actually works although the remote control currently looks like this. More 3D printing when time allows.
It weighs 153g where the official limit for this class is 150g
(and I'm really not sure there's 3g of excess servo lead in there). A smaller battery is the obvious solution - this one is 370mAh which probably more than needed. OTOH I bought four of them so I'm financially pretty keen to save the weight elsewhere.
