APOC - Beetleweight

[Igor]

I really liked the innovation of the early series of Robot Wars.
Roadblock simply turning bots over, Cassius doing a back flip, Hypnodisc, Razer, etc. PSYCHOSPROUT!
But then I liked things like Scrapheap Challenge and The Great Egg Race where different solutions are found to the same problem.

It's not just about mindless destruction. (But mindless destruction is still good fun)

Unfortunately the current champions, Tombstone and Carbide, are very similar so I've finally decided to give it a go. I know my creation is unlikely to win anything, I just want to have a bit of fun and if it inspires someone to make a bigger, better, badder version, then fantastic.

I went for a Beetleweight as it's still relatively cheap but not as restrictive on weight as Antweights. I really want to create something different.

So I give you APOC (A Proof Of Concept), a walker. Having looked at Klann, Jansen and even Trotbot mechanisms, I settled on a modified Chebyshev mechanism. Modifications include the use of a single crank and a double parallelogram to keep the legs vertical.

Photos show the movement as the crank rotates. This will form half of one drive "pod". Each pod will consist of 2 of these mechanism, 180 degrees out of phase. There will be 2 pods to provide tank steering.
This only provides a single degree of freedom (pitch), so the aim is to twist (yaw) or tilt (roll) the pods independently from the forward/reverse drive to give a 2nd degree of freedom in a different plane.

This is a first build so mistakes will be made.

[R9000]

This looks fascinating! I really hope it works well!

[Igor]

Second mechanism added 180 degrees out of phase to produce one drive pod.

By placing the rocker on the opposite side of the crankshft, one crankshaft operates both mechanisms.
Only need a 1 cylinder type crankshaft rather than a 2 cylinder type crankshaft is needed so it's a bit less wobbly

Some hex nuts replaced with nylocs. Either the hex nuts tightened and caused binding issues or loosened and the screw heads clashed between the two mechanisms.

Drive pod now runs a little free-er under manual test.

Brushed motors ( 12V 1000 rpm) on order. If the mechanism doesn't work, I can use the motors in a more conventional bot.


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