Lol I want to build a huge mechanical snake!
http://www.snakerobots.com/S7.html
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Lol I want to build a huge mechanical snake!
http://www.snakerobots.com/S7.html
And what exactly do you plan to do with that?
Frighten the girls away, ye will.
Here are some festo air-muscles in opposition to each other. Even a home-made muscle of that size can lift over 60k. These are rated to 6bar and are being pushed to new speeds (normally top speed is 100hz, or 50hz for home-made)
Festo ones are very expensive, but it's entirely possible to home-make air-muscles with decent performance quite cheaply and using kevlar braid instead of nylon which most use.
http://youtu.be/j71vV1xq9jU
I highly recommend a search of "festo" on youtube, they've done some amazing vehicles and robots.
Sounds like a great robot design, would love to see it going! If you have the technical ability then definitely go for it. Do Not Make A Brick!
Thanks for the encouraging words! And nice to see you on the boards. Been a busy have we?
It is the story of my life that I know a bit about the weird and wonderful, cutting-edge stuff, but am a complete novice at the basic stuff that is the real foundations of it all. So lots of learning to be done.
And there was never any chance of this turning out as a brick!
I'd say both ends of the opinions here are right. You will benefit hugely from building something simple and putting it in the ring to understand the physics involved. The bent m20 bolt that was mentioned was on the front of our robot. We're still learning by the millisecond, a year down the line and barely beyond our second robot. The other thing that matters, though, is to not discourage. Don't think the only way in this hobby is to build like the masses. Without people with wacky ideas we wouldn't have our hobby at all.
With that said, please go and build something weird and wonderful. If you're prepared to learn from it if it goes wrong then everything is to gain.
Yes very busy. Just designing my next machine called Goblin. That too will have Kevlar armour so long as tests look good. An to hit some test bits with predator to see how usable a material it is.Quote:
Originally Posted by Bacon Wizard
We've used Kevlar on Mute for a long time and its still the same pieces on the side that were originally fitted, its 8mm thick stuff that was used as protection in Bank walls, we've recently fitted some new pieces to the top of Mute to stop the axes.
If the stuff does get cut (nothing has ever made it all the way through) we just add some hot clue and apply a slighty amount of pressure with a big hammer and its like new
http://i150.photobucket.com/albums/s.../Muteready.jpg
Its the black stuff with white patches in middle of mutes side pods, the white is were is been hit by another bot and just skimmed the paint off
:) Liking the look...
Yeah, don't worry. I know enough about composites to know full-well that kevlar armour would be just fine if applied properly. If it was a carbon fibre/kevalr composite, it could be made almost twice as thick without any weight considerations. And if sheer-thickening fluid was applied to a non-composite layer of fabric on the top, it'll stop absolutely anything.
what resin would you recommend? im still pondering
Definitely epoxy laminating resin. It's more pricey but don't even think of using any anything else for combat. On paper it's brittle, but it has cross-linking properties with some but not all fibres. Kevlar and carbon, are both suitable. Much stronger than vinyl-based or basic fibre-glass material.Quote:
Originally Posted by james...venom
Spend money on a good hardener. Some of them have UV protection too ((UV degrades epoxy) and that's handy if you don't want to paint it.
You very much need to do it under vacuum-pressure (vacuum-bag kits) and I'm not sure I can recommend using pure kevlar for fight-bots (am still looking into this) but kevlar has no structural strength, only resistance to penetration and dispersion of forces. ie, you could end-up with the resin cracking from blunt-force trauma despite a weapon not actually getting through the stuff (think wire-re-enforced glass) Which is why I am thinking carbon-fibre/kevlar blend might be a better option anyway.
Carbon is actually slightly heavier than kevlar, but the added strength aught to mean you could include a core material/filler and get a thicker, lighter and yet stronger shell overall. (In theory!)
I am looking into polycarbonate composites which I thought sounded like a great idea but not too much luck so-far. Maybe Polycarb can be the core material if that plan turns out to be a good'un.
Forgot to mention, of the layering epoxies, the more of a pain it is to work with the better.
You get some that need baking. Others room temp. Guarantee that the one you'd ideally like is impossible to do without special kit. Which is why I'm more likely to save-up and get a firm to do it for me :(
Right, have finally got some proper figures for my proposed X-bow style actuated "captive bolt" or spear type weapon.
A collector I've been able to reasearch has a hand-held arbalest which weighs 18lb and has a draw-weight of 1200lb (5,200N)
There were larger and heavier ones that went up to x 5 this power for use from ramparts.
These were using spring-steel whereas we have carbon fibre, and the weight includes a large stock which I will not require at all. We also now have the reverse-energy configuration and compound-bow technology.
I am confident that I can seriously hurt an opponent bot with this arrangement, and possibly the first move should be a simple FW (not a walker) with this kind of weapon on-board for testing. I need to know how effective it is before designing the rest of a HW walker, because the entire bot will need to work around the size, shape and weight of the weapon.
It WON'T be top-mounted though, it'll need to be housed within the body somehow. "Reverse-energy" type arrangement will help make this possible, but it's still a concern.
My plan for my hw is to have a high pressure pneumatic ram with a spike on the end, it should make 1000kg of force which I'm hoping will be enough.
I know a lot of people have advised against weapons like this in the past but I hope it will be able to do something and at least it is not another flipper!!
I would gladly take a shot gun to any of my machines. A tethered projectile weapon will do little damage
No wonder: a shotgun is unlikely to deliver much more than 3500 fp. Far less than what I am now proposing.Quote:
Originally Posted by typhoon_driver
An Axe is just a projectile tethered by a handle. Its merely a question of how you generate force. I suspect you think this is gonna be an arrow on a bit of wire. It's a linear ram, but not pneumatic.
You store energy up in a spinning fly-weight and release it upon contact using a spear-tip or "tooth"
I'm planning to store energy using modern materials used as springs (steel won't do the job, it's too heavy and sluggish) and release it upon contact using a spear-tip.
It all comes down to how much energy you can store.
It's not been tried before as far as I can tell, but the figures stack-up. So I'll trial it and if it doesn't do the job I'll move to plans B and C.
At the worst, I'll turn it into a straight crossbow without using it in a robot at all.
sorry but i can't really see this being an effective weapon, all it will do is push the 2 robots away from each other or at best a small dent in thin metal
even with some of the heavyweights on robot wars they either made a small hole in thin armour or pushed the robots away from each other and they had 100kg of weight absorbing the force where as feather have such a small amount of weight and less grip on the floor
this is assuming i have it correct and your building a feather
Plargen, I will most likely be building a series of very standard almost off-the-peg feathers on which to test certain concepts, but corvis is eventually to be a heavy. I will have 200k to play with.
If you have the technical ability to create it that's great. Its really good to see some different designs and thinking outside the box. As an event organiser, if you could send some technical drawings of how the projectile will be tethered and the mass of the object being fired we can make sure it is safe to contain in the arenas. It may well be if its anywhere near as effective as you suggest, and you seem to know what your talking about, we may want to arrange some testing of your machine at our workshop to be sure it's safe to contain inside the arenas
Lemme build the damn thing first!Quote:
Originally Posted by james...venom
It's not a projectile, it's a ram. But would be more than happy to provide drawings, video of it working etc before attending anything, and let you test it, sure.
the 200kg version sounds like it could have potential
Well, heck it might not work, but like I said: i get a very cool item even if it's not up-to this particular job.
I've seen a broadhead arrow (that's the wrong sort) go clean through 3mm hardox, and that was just from an ordinary x-bow. So I'm in with a chance if I can keep the weight of the ram's shaft down.
The difference is its very easy for us to calculate the force a spike might have on a ram and we can simply work out if its likely to fail and the spike come out etc how ever we would struggle to say if a crossbow type method is safe without seeing it and testing it first. As I said its great someone is thinking of new methods :)
Yeah, I get it completely. It's an unknown quantity and needs to be checked-out. No problemo.Quote:
Originally Posted by james...venom
We're a year or two off that occasion anyhow.
News: My mate Vikki is now on-board as chief advisor, using her experience as an aircraft engineer. I am currently having a crash-course in space-frame design (HW corvis will deff. be a spaceframe, not monocoque)
Armour is looking like polycarbonate plates, each of which is attached to the frame via tempur-foam bushes and stiff springs and covered in 6+ layers of sheer-thickening-fluid-impregnated kevlar (not in a composite) No chance of being pierced, and the rest is all about shock absorbing.
Have contacted custom carbon-fibre parts manufacturer in Uk for advice on arbalest weapon: I can't make it myself: too much chance of air-bubbles in the composite (and those would explode under the pressure, making a crack in the weapon = fail )
Am now looking for a really basic FW on which to test armour and other ideas. No intention of winning anything. Just want a RC, moving, wheeled, box that's viable.
:)
Tiberius. n'uf said.
yeah, the comparison is a good one, to be fair.
Is your armour going to keep out Tibs's claw though? The weapon does interest me (waaay back in my ridiculous vapour design days I had an idea for a giant crossbow spike) but I'm curious as to whether the Hardox sheet that you mentioned being penetrated was anchored down or not, because I can't not visualise this being a very efficient and effective way to propel yourself and an opponent in opposing directions rather than actually penetrating anything...
If you keep the mass of the ram and spike down and move it very fast (low moving mass + high flow rate) then you have a chance of stabbing through something.
As mass of the spike is <<< robot mass then they shouldn't get flung apart as much but still pack a punch due to having a lot of momentum. High velocity should also reduce the time the impulse acts making for lots of force. You could try recessing the spike into your robot so it has ample time to accelerate before hitting anything.
I think it should be the other way round, the spike should be made from very heavy material like tungsten and be made as small as possible - same principle as used on armour piercing KE rounds. Having said that, I cant see a crosbow launched tethered projectile attaining the velocity of a cannon launched KE penetrator... But still worth a try!Quote:
Originally Posted by daliad100
Yeah, I am still working this out. It needs enough mass to be felt by the other bot, but needs to be light enough to get some speed-up.
Walking is never going to beat wheels for pushing. I'll just have to live with that. I'm hoping geckskin will be commercially available so that at least we can withstand a pushbot.
Armour-wise, I am confident you won't get through it mon. I'll be using sheer-thickening fluid on the kevlar. It keeps out a 50cal bullet, so you don't stand a chance of penetrating it, frankly. Blunt-force trauma is a different matter.
And of course walkers are inherently flippable.
That's the plan. But I don't yet know how large the bow itself needs to be to generate the required forces. That'll pretty-much dictate the rest of the bot's design.Quote:
Originally Posted by daliad100
I'm counting on the reverse-energy configuration to help. Here's an example of perhaps the market leader for ordinary bows right now. Imagine mine with the arms 10 x thicker and the whole thing narrower.
http://youtu.be/yhVNMoRXjOY
Cocking it is also a concern. I could end-up with something that takes 30 secs to re-cock but which nobody want's to get hit-by. Or it could be weedy and quick. I need to do some proper maths.
Has anyone ever attempted a bot that anchors itself to the arena floor with suction for better weapon-deployment and/or anti flip?
Magnets....
Yep, John Reed with Killerhurtz -see the movie Antazz posted.
There a turbine and extremely fast running motor created suction between bottom plate and floor.
In Beta he used a gazillion magnets.
But anti-flip. Worst case scenario robot and piece of floor get airtime. The flippers atm are "powerfull".
Yikes!.....Quote:
Originally Posted by maddox10
Very interesting bots, I like the thinking. I've been looking at gyroscopes also.
Your avarage heavyweight FP flipper uses a 100mm bore ram with multiple feeding valves.
5*5*pi*55=4300 kg of force.
In feathers a 50mm bore ram ain't an exception. That's a ton of force...
Doesn't seem much point trying to resist it then.. concentrate on SRMECH innit.
I can see why people enjoy FW.. power to weight ratio must be through the roof.
Hannibalito 4 uses a 78mm bore FP ram.
Containing those 2.5 tons of force ain't that easy.
In our Robo Challenge arena we have a 4mm hardox floor which means magnets are a good bet and alot of people use them. In heavies, Its probably not worth looking at as the wooden floors get damaged and your likely to be sucking in bits of dust, broken bits of MDF/Plywood etc and cause your self problems.