17/06/2024
Time to talk about the hot part of Freak.
The custom built hub motor.
Following on from my old undercutter Splodeyboi I wanted a more reliable weapon system. It had three flaws. Belts breaking, motor burnout, motor getting hit.
Having seen the very durable hubmotors on Daedalus, Saw Loser and Night Fury. I would give it a go.
I chose to start with a tarot 4008 brushless motor. For a number of reasons
A low motor because a hub motor gains a lot of extra height with big bearings.
It’s a motor that can take more power than I was planning to throw at it. A margin of safety for burning out.
Low rpm. So I can put a large weapon on it without it breaking the tip speed rules.
Now I have to design a strong structure around the internals of the motor.
The central fixed shaft is a 10mm shoulder bolt. That pulls everything tight together and threads up into the top crossbar. mounting the hub motor to the frame with a solid core piece.
The structure that holds the assembly together is turned and milled from 6082 aluminium.
The donated stator and rotor components are secured with epoxy. And I added tiny keyway after attempt one proved they would still spin given the right circumstances.
The magnets and the windings are coated in a mix of epoxy and glass microbeads to fill gaps and keep everything exactly where it’s supposed to be during fight chaos.
Onto the very bottom of the hub motor fixes the hardox steel weapon discs and bars. Made to match the bolt pattern from splodeyboi so I can use the old weapons I’ve had stored away.
By June the entire robot was complete and off it went to robot rebellion. Fingers crossed that it would do everything I hoped when tossed into the real world very abusive test that is the arena.
It never failed. It did things that I know would have broken splodeyboi. I couldn’t be happier with it.
