I decided to start on the electronics of my new spinner beetle. I knew everything needed to be tight and compact and given that I am running on 4S to get the most out of the weapon motor, this presented a few problems.

The first is that the 10A Botbitz don’t take more than 3S so that put them out for drive ESC’s. Second the battery was going to be quite a bit bigger than the 3S in Anvil and the other beetles which would make the chassis larger and thus heavier. Finally running full power on the weapon motor meant I needed to get the larger ESC, a 70A Red Brick, taking up more room and weight.

I was going to use the 12A-RC Sabertooth I had lying around from an old feather design but then I remembered… my Antweight. I had got a 5A-RC Sabertooth for an antweight that never made it beyond CAD.

Looking up the stats I was pleased to see that it took 4S and was far smaller than the 12A. 2 hours of staring at the parts later I ended up with this…

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After removing the Red heat shrink and the pressed Alu heat sink on the Sabertooth, I put some thermal compound on the 5A’s Fets and with a glue gun secured it to the top of the secondary heat sink on the Red Brick.

From that I ran wires from the Red Bricks power terminals up to the 5A to get power to it and simplify the wiring. After pre-attaching wires for the drive motors and grouping together the signal wires neatly I shrunk the two ESC's together into one compact unit.

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Sabertooths are known for not being too reliable in combat if they are not protected or reinforced. Here the heat shrink keeps the capacitor in place and I also added some extra glue to the base. All the internal wires are heat shrined together in pairs and clusters so any stress is spread across all the connection points and now rather than being over 35mm high the whole unit is now 27mm, just enough height left for some Velcro to go in the 30mm tall chassis.

There are some down sides to this design. Sharing heat sinks is one issue and possible overheating. Also if anything breaks it means the whole unit has to come apart which might take two long at an event. However this should be a good first version which I can improve on over time.