Corvis (temp bot name) rough ideas.

[Bacon Wizard]

True enough lol (great stuff!!)

i'm hoping the layered-scales nature of the armour will asist and mean i get to replace individual scales. HOPING...

Weaponry still remains very open right now, but bringing together some of the othe ideas and with ever more research into them I have some better sketches now and can begin cardboarding.


it looks an aweful lot like a multi-legged tortoise with the segmented plates and gomboc-shaped body. Potentially prophetic

Rename: Turtle War?

[Bacon Wizard]

Just working on the "plug-ends" for air-muscles. The muscles are contained in kevlar so are pretty solid, but the ends can pop-off on home-made versions.

I don't want to risk a poorly made or worn one going regularly, nor do I want to dedicate my time to the fiddly manufacture of each and every one, potentially needing fixed after every fight. So thinking of having them made according to the following ideas. Ignore the figures: they're an accurate representation but not necessarily what I'll actually be running.

muscle-ends.pngmuscle-ends 2.png

Any comments? Glaring errors spotted?

[craig_colliass]

I can see this type of pneumatic actuator shows promise. if the end assembly could be made at reasonable cost this would be an interesting project to follow up Are there any Roboteer machinists that can quote for these parts?

[Bacon Wizard]

I can see this type of pneumatic actuator shows promise. if the end assembly could be made at reasonable cost this would be an interesting project to follow up Are there any Roboteer machinists that can quote for these parts?

They can exert around 35 x the force of the same size cylinder (at rest) and weigh a fraction of the amount. The downside is they only move 25% of their overall length as a rule of thumb.

Hence why they are the basis of mi proposed walking system, and potentially of a weapon too.

Am about to order a roll of kevlar braid from Australia

[Bacon Wizard]

Had a chat with the carbon fibre layup company finally.

The low-down is this. We can lay up as much carbon fibre as needed to make a very high-power spring and expect a draw-weight of a couple of thousand pounds. But I can't afford it, and it'll all go wrong (break) if it gets a dry-fire at the wrong time, or smacked at just the wrong moment.

The weight is not an issue, although higher than I had thought because of the re-enforcements I would need to make to the arm-ends and cams, and to prevent anything from possibly flying-off and hurting folks. And then I have to have an actuator to re-set the spring.

Despite all this, it would still be both light and powerful. But not, I suspect, quick to reset. And the layup folks give me some rough dimensions and it'll take up a LOT of room in the bot.

All for the princely sum of circa £1000 !!!

In short, I think we're looking at plan B. It will not surprise you I'm sure, that plan B is based on the spiked-club of a mantis-shrimp lol

[Bacon Wizard]

Managed to acquire 13 festo pneumatic solenoids, some of them fast-acting and a couple of which are actually vacuums. Happy days. All 24v.

[Bacon Wizard]

What is the general opinion on the following? This weapon could be best described as an upside down axe, or spiked-club.

Theory is that the bot will have a spinning gyro/flywheel inside, and that by engaging a clutch I can use some of that energy to actuate the following loose design. Firstly, is this simply a loophole in "no heavy weight spinners" which it would nevertheless get disqualified-for? In which case, the obvious alternatives are my next port of call.

And secondly, how about the concept in general? The idea of the spike is to potentially get under the other bot, or if not then give some penetration.

weapon 2.PNG

It's designed to be a kick in the nuts. lol

[Bacon Wizard]

OK.. wow this is a learning curve! But that's good

Have been playing with circuits.. still not used to the maths, but it's all simple really just a bit of a shock after years of not doing any...

It turns out that bumping-up the voltage from 24v to anything between 24 and 72v is really rather easy. People have been talking about discharging huge capacitors which I guess is good for weaponry,. but for overvolting motors off the max allowed battery cells in series something far less "OH F**K"-ish is required.

I bought a 555 noise circuit from maplin, which ends in a Transistor.. that all creates a square wave in your main supply (ie, oscillating) which because it's oscillating can be transformed up by the usual means,. Or a lighter version simply charges a series of 24v capacitors (smallish ones) in turn and then discharges them in series. An inductor is required to drive the circuit and to pull current from the batteries, but it's not as big as a toroid transformer if you don't want the weight. A bridge rectifier, and various capacitor/inductor combos can be used for a smooth result.

Job Done.

I am playing with using the same toroid core for both inductors, because some of the feedback and amplification effects are really interesting albeit over my head at the moment.

This may be very naive of be, but I'm gonna look at using motors as the inductor or even transformer in circuits too.. that way, there's little added weight.

[daveimi]

This is a stupid question but what do you need an inductor for?

[Bacon Wizard]

This is a stupid question but what do you need an inductor for?

Nothing stupid about it.

Couple of reasons why you might want one. One is to smooth the current. They don't like to change quickly and so are to current as capacitors are to voltage in that respect. Think flywheel, only electrical.

The other way, is to drive the rest of the circuit during the off-duty cycle of your oscillating dc source, if you need to: again, flywheel. Buck booster circuits use this, as per picture:

600px-Buckboost_operating.svg.png

Another but complex (to my new eyes) thing is by winding it with 2 solenoids and supplying these from different directions, you can set-up feedback loops which cause their own oscillation as the field reaches saturation, and then collapses. You need oscillating DC if AC is not available, and in this way an inductor can perform several functions at once, including a transformative one that is considerably greater than a traditional toroidal transformer of the same size.

And finally, my understanding is that in the correct setup, an inductor with a decent ferrite core, due to it's inherent stability (current) can actually pull greater current from your battery than would otherwise be the case. This of course discharges it faster and I can see that you need to take care not to damage the battery. Believe me, I'm still working much of this stuff out.

Considering it's basically a loopy wire, I think they're quite amazing bits of kit.

[daveimi]

So how come you need this in the design?

[Bacon Wizard]

Need? This is Robot WAR. It's not about doing the minimum required, it's about making your opponent cry like a girl in the arena, then going for a pint afterwards. Nobody NEEDS better weapons, faster speed, more grip.. but it's all a bloody good idea if you can get it, no?


I have one, single, serious motor. It's an Etek and is driving my pneumatics and the weapon. ie, everything.

It can run on anything between 12v and 96v providing it's cooled and that the time is kept shorter with high voltages. 10Hp @ 48v

I could stick with what it will do without such measures.. but why the hell would I limit my bot to that? I want to smash the crap out of my opponent up to the point where I've won the bout, not politely tickle it and then wait in line for my turn. I want to shove them wholesale into the wall so that they're left dizzy and nauseas, not just amble to my death. I want the weapon to knock them into next century.

I want to be faster, stronger, more mental.. if I have a chance to squeeze a bit more out of my motor when I need it, I'm taking it. My design is already dodgy enough, being a walker. I'm not going to muck-about with anything else. I'm taking every advantage I can.

Frankly, I am a newbie at this, but working out a circuit that can instantly turn 24v into 72v (minus losses) wasn't hard, and I don't understand why everyone doesn't have that option. The weight of the circuit isn't significant for a heavy.

My 3 x 24v battery packs will be in parallel, and most of the time I'll want to keep it to 24v, and last the distance.

But when I absolutely need to treble my output, it's there for me, instantly.

[Max]

Will you not be exceeding the 50v AC maximum rule wity your design? I don't fully understand it but it sounds like you are turning it to AC, bringing it up to 72v then converting it back to DC. 72V AC obviously excess 50v AC

[daveimi]

It just seems a bit "over-engineered" ie...why do you need an inductor simply to bring in more voltage (which you could do with a simple remote switch)? As engineering apprentices at 16 we were given the train of thought that in most cases simplicity will equate into reliability.

[Bacon Wizard]

Max, DC boosting is well-known, normal, ordinary and old (WW2)

All you have to do is turn the supply on to charge caps, and turn it off again to discharge them. You don't even have to turn the DC off, just re-route it.

Intermittent or unregulated DC is way different than AC.