Team Saint Robot Builds

[craig_colliass]

Hi Dave
I always say "If you always do what you have always done, you will always get what you always got." I'm doing this to see what effect it is going to have on the pushing power of the robot it isn't the final design but a test this information will help the next design step.
you build what you want to and see how it works. if we don't try new things we will be stuck with what we have, for me the whole point is to try something new. It's an inventors sport after all.
People will give advise and this is good, but the decision to try something is yours.
I have a robot kettle,
an 8 legged robot walker,
a HW robot that does hand stands,
and one that swings a 4 foot sword,
I win next to nothing but have loads of fun
Remember failure isn't a sin, but sometimes not trying is!

[daveimi]

That was all I needed to hear Variety is the spice of life.

[craig_colliass]

IMG_2026.jpg
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Some pictures of the new project a pneumatic walker, this is going to take a long time to finish but you have to start somewhere.

The configuration is ATM 8 legs, 2 degrees of movement, 16 actuators and at least 2 on board compressors.

The pictures are of the function mock-up with mechanical valve control, and the next 2 are work in progress to make the leg patterns to get the shape and distance right before cutting 8 of them out of 20mm HDPE, at least that's the plan to start with.

[Eventorizon]

A giant 110kg + pneumatic Octapod... this will be so cool when its complete!
Or is this not for combat?

[craig_colliass]

The target weight is 27.2Kg but I think this may be a bit difficult/impossible to achieve.

One of the reasons for doing this is to prove the impossibility of the 2 degrees of freedom rule we have in combat robotics. (and as a result no walkers!)

If I can I might use it in Featherweight fights, but the main thing is as a design and build exercise. the design is still fluid as to how it will look and even how it will steer.

But first things first lets get the leg mechanism working!

[Eventorizon]

I think the 2 DoF rule s there to prevent shuffle bots, which it should be IMO. But yes its a shame there are no walkers. I have a few ideas but no money to test them out sadly.

If you can get it working properly though it will be amazing!

[craig_colliass]

yes I have in the past argued about what is and is not a shuffle bot.

https://www.youtube.com/watch?v=4Zjh62hh2A4

under the present rule Pilgrim is a shuffle bot!

[Eventorizon]

Yep, same goes for the giant Attacknids, they don't count as walkers despite their complexity. As you know though, Pilgrim, the Attacknids and shufflers are fundamentally cam based, its just what comes after the cam that is different. While I would look at Pilgrim and the Attacknids and call them walkers, when it comes to the rules we can't have exploitable rules that would allow shufflebots to gain a massive advantage. Yep, its complicated...

[maddox10]

Oeps.

Pilgrim is a Strandbeest. A cam based shuffler.

[Rapidrory]

In antweights, almost anything without wheels passes as a walker and gets 50% weight allowance, and yet still almost no one makes them; I won the 'best walker' award at a previous AWS because I entered the only walker! So even if the rules did count cam based shuffle bots as walkers and gave a big weight allowance, I don't think there would be a sudden explosion of them.

we can't have exploitable rules that would allow shufflebots to gain a massive advantage

I don't see why not? If you're putting the effort in to building a walking mech, you're accepting a hit on mobility to gain extra weight. Even a simple shuffle mech is difficult to do well and and light weight enough to give you weight spare for weaponry. Even if other weight classes went with the extreme of ant rules with 50% extra for a basic shuffle bot, I think we'd see one or two shufflers which would be a good thing, but I doubt any of them would be winning an event any time soon..

[craig_colliass]

Thanks Rory I couldn't put it better myself, I have tried to explain this in the past but gave up!
Just leave this here


https://www.youtube.com/watch?v=_qTQsH52r8U

[Rapidrory]

That's mad Craig.. I love it! a small air tank might be good to smooth out the air supply; that compressor sounded a little sad :L

[craig_colliass]

Thanks Rory I'm thinking of using a plastic coke bottle

BTW under the current rules this is a walker!


https://www.youtube.com/watch?v=JlSayvpQH54

[craig_colliass]

Just put this here as the second video in the walker project.


https://www.youtube.com/watch?v=o0T_txuo86Q

The project is going OK at the moment and the leg configuration seems to be OK for now.

They are made of 15mm HDPE, stuff I had left over from making all the wheels for Gabriel. At 15mm it is stiff enough to support the 27kg.

I'm now going to be looking at making the other 4 legs and sorting out brackets for the robot. the legs will be fitted on a backbone style chassis with a platform on top for the compressors and v/v gear. I'm not sure how to do that yet but lets get the legs done first!

[Max]

Wow this looks incredible! The audience will go wild when they see this walking into the arena.
I am curious though whether it technically has 2 degrees of freedom, as it is still essentially cam based surely the position of the legs is fully defined by the angle of the camshaft meaning 1 degree of freedom? And I guess you wouldn't be able to demonstrate two degrees of movement separately.
Maybe this could be overcome by controlling it with a microcontroller and solenoid based valves, but assuming you have a fixed walking gate it could still be classed as single degree of freedom. I guess this shows just how ridiculous the 2 degree of freedom rule is as in order to have a true 2 degrees of freedom you would have to be able to remotely alter the gate in real time which is just impractical in a fast pace combat environment