Hi all - My first bot (full-body hammer kind of thing).

Hi there, my names Ellis, I'm 13 years old and I'm a newbie in the fighting robots world... or atleast the building part, I was watching Robot Wars before I could use the TV, and have most episodes on tape. I was also very into TechnoGames slightly later on, Scrapheap Challenge, Junkyard Wars etc. So I'm here now to try and fullfull that dream I've had since I was so young.

Ok, well, since this would be my first bot, I'm going for a featherweight. The basic design is a full-body hammer like robot, like Tornado or Storm II from the RW days (obviously, much smaller).

I have the basic design concept in my head, and will soon be making some plans and sketches. What I have in my head so far:

-2, maybe even 4 drill motors, with the gearing system still attached (will make sure the cogs are steel or other, although drills are drills afterall, still worth checking. And I do know that it would be massively heavy).
-ATLEAST 4 wheel drive, looking for 6, and I'd achieve that with chains if I do (much lighter than messing around with cogs, and less mounting and things to deal with).
-Looking for a spinner resistent setup, god knows how I'd achieve that with such a strict weight limit, but maybe leather intertwined with ali would work? (Steel front end, I think, but that means welding would be very hard, any other suggestions would be greatly appreciated).
-No weapons yet, I'm thinking of a shaped wedge/ramp on the front for extra control whilst shoving other bots about. (Basically, a typical ramp, but with a small lip like thing at the top, preventing other robots from just flying over the top when I slam into them, also, if flipped, it wouldn't render the pushing power I have useless, it would just trap the opponent underneith).
-I THINK I'll go with invertible but I'm not sure, I'd need other opinions on things like that.

LOTS OF WRITING *phew*.

So yeah, speedy, lots of torque, skid steering ofcourse and a good driver (RC cars since I was 3, you get quite good after a while! :D)

Also, on a slightly different note, would just being completely RELENTLESS (ie: ramming spinners) repeatedly, and not allowing them to get up to speed be a good tactic?

That's about it. I think.
OH! And the bots name would be Relentless, but I spotted itt's been taken by someone else... So, I was thinking BladeMaster or something would be good. Again, opinions would be great!

NOW GO AND GIVE ME YOUR OPINIONS ON THE IDEAS I'VE HAD! I'll need all the help I can get.

Thanks,
Ellis.

Firstly hello Ellis and welcome to this crazy hobby :proud: hope your designs come to fruition.

Leather and ali wouldn't stop some of the spinners going around...if Nick has his way very little other than a concrete bunker will stop featherweight spinners, but he's certifiably mad :P Your best bet would be either steel or Hardox (which is a wearplate steel from Swedenland!), if you're not using any active weapons and have a small enough chassis you can probably go for that all around. I'd advise at least 4mm thickness, possibly with 10mm or more of some plastic behind it, bear in mind Hardox only comes in 3.25mm and above thicknesses.

Go for 4wd with 4 drill motors rather than 2 motors and chains, chains mean extra work to get the wheels aligned so they don't come off, tensioning, and they can come off mid battle...as it's your first machine you want it as simple as possible.

I'd definitely go invertible, a few robots have tried self righting hoops but those can be hit and miss, and also get ripped off :P with the amount of flippers and wedge type machines around you're best off being invertible or having an active method of self righting (which will eat into your weight)

Regarding the tactic of ramming spinners and not letting them get up to speed, that's pretty much all you can do with spinners :P

Hope this helps.

Ok, so, invertible it is. That WAS my initial intention, since after watching some of these bot fights on Youtube, it's very rare that one won't get flipped over.

And, regarding drills, I've got a pretty low budget, would lower-end do? (cordless, ofcourse).

Oh. And one more thing, invertible means armour on both bottom and top of the bot, and since they are the 2 most unlikely spots of a bot to get damaged, I could surely go with thick plastic? Or plexyglass or something... I'm just trying to get the best power to weight ratio I can. Light and fast can mean weak, but heavy and strong can mean sluggish. I want the best halfway point, drifting towards the lighter side, speed and agility being the key.

ARGH, god knows, I don't know. How about slightly more exotic metals like Kevlar?

Kevlar ain't a metal, lol.

In terms of strength to weight ratio, grade 5 titanium is the best material out there for armour - it's expensive stuff, however, and pretty unnecessary unless you REALLY need to keep the weight down. I reckon your best bet is to armour up with a big 3.2 or 4mm hardox wedge...actually, you could realistically armour the whole thing with hardox. There's at least two nasty crusher / axe bots out there so if you've got the weight one might as well stick at least something on the top and bottom, especially as you'll probably end up bolting a lot of your components to the bottom plate. Ali is a good bet for the bottom plate - though get some decent engineering grade material (6082/7075/etcetera). Avoid plexiglass or similar plastics - the 2 best for robot purposes are polycarbonate and UHMW polyethylene (which is a bit flexible, good for outer armour, not so good for structural parts).

12v cordless drills are pretty much all the same, so get the cheapest ones you can :-) you can always build the motor combination yourself later. Personally, if you want to do something like Tornado or Storm, I'd say you have to look above just drill motors as they're really nothing special - the key to those two robots was their extremely powerful drivetrains. You may want to think about using 6 motors, or bigger ones (18 volt DeWalt hammerdrill motors or RS775/Speed 700 motors come to mind), to get the effect you're looking for.

As for the lightness issue - the only reason to use lighter materials is to be able to stick in more of them, or other components. Building anything lighter than the weight limit is just not a good idea - you end up lacking traction (so you can't push effectively), you lack momentum so your ramming attacks aren't as effective, and you end up flying miles when you get flipped or hit by a vertical spinner.

Joey, I'm not mad :-P just a bit more ambitious in engineering terms than you :twisted:

Ok, well, I am only a beginner, and have NO idea what would be good for what, could you possibly link me to something you would see as decent? (Motors wise).

And thanks for the helpful comments guys, keep 'em coming.

Here's probably the easiest off the shelf solution: http://www.robotpower.com/products/magnum775_info.html

Basically it's a planetary gearbox designed for a RS775 sized motor, which is a good step above a drill motor in terms of output power - in fact a couple of those would do a good job of powering a pushy featherweight, with the option of upgrading to four at some later date when you're feeling a fair bit richer.

A robot with a couple of those (or a similar drivetrain) powering it and a big ground scraping hardox wedge on the front stands a pretty good chance of being really effective. :)

Fantastic! Thanks man.

Now, I'm thinking chassis and armour again. I like the idea of a mainly ali or possibly thick polycarbonate shell, with a steel or some other HARD metal for the front scoop/wedge like thing. Titanium for now is just too expensive, and I have no idea where I could get it localy, I mean, postage via the internet is an option but it would much harder to get it just how I want it.

So, I think titanium can be ruled out for now. So that leaves, thick plastics, steel, ali, and very basic cheap iron. Iron can be ruled out I think, it's quite heavy as far as I know and not massively strong. Cheap though, and I can get it locally.

Ali, obviously, I can't weld it. Which could be a problem, but it's a fairly cheap option that I can get localy.

I like the idea of polycarbonate, maybe not for the side and back panels but for the lid? and the belly it could be good.

And I'm pretty set on steel for the wedge-like bit, simply because it'd give me alot of strengh and a good amount of weight on the front, for extra BASHIN' POWAH!

Lol. Any other metals that aren't crazy expensive?

EDIT: I am in Spain, English, but in Spain. So that particular motor is no use since the postal cost + taxes is just too much for me at the moment. English websites are great, since it'll be much cheaper and faster. Anyone got a similiar thing for the UK? Or even, Ebay? Second hand motors, is that a bad idea?

By the way, I am looking on google myself, I'm not going to sit back and let other people do the work, it's just that someone might know a good source.

Hi Ellis, and welcome to the forum.

There's been some good ideas and information mentioned so far, hopefully they'll help towards your design.

Take a look at this video:
http://www.youtube.com/watch?v=28_rB...om=PL&index=49

Umm, kind of, it looked like that bot was more speed than push but it looked about right. And that was with drill motors? Wow.

Ok, well, great, thanks. That makes things much easier!

One more hurdle. Wheels, where the hell can I get wheels?! 100mm... I have no idea if that sounds right or not. Hehe.

Anyone know any good UK suppliers?

I believe Robo Challenge sell special 100mm blue wheels that screw directly onto the shaft of drill motors, so they should be a good bet for you if your using drills.