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Dave, yeah I'm planning on making one too. Been umm-ing and err-ing as to what design to go for and what parts to use for a while, but just recently decided I'm going to try a kilobot version of a featherweight design I've had kicking about in my head for ages but that has never been built (Snakebite) so that means I'm going for a vertical crusher :)
seeing a crusher would be cool.
Theres no real size limit. Just some of the things like the pit etc ill need to see what size most robots end up being. Oh pit will go up and down, Might have pit release mounted so that it cant move about on the arena walls but can be pressed so instead of pit being opened by a person its the robots that actually open it. Dunno yet tho, Was thinking about having somthing similar to that spinning floor section on robot wars arena floor. Then make it so a hub can be bolted to it then have a disk or bar that bolts to that so theres a fixed spinner in the arena, Will be activated for maybe 30 secs after a robot hits a button. Depends if people are bothered about getting there robots smashed. Somthing like a 2kg spinning bar hitting a 1.3kg robot could cause a bit of damage.
i think Ive seen an American kilobot arena with a similar floor spinner..
2kg might be a bit much.. i think theirs is basically 4 stanley knife blades bolted to a spinning hub.
Crusher would be abit lame in 1.3kg i reckon but a pneumatic flipper could be awesome.. I was looking at doing that, just not sure what id use as a reservoir for the gas... might make a flippy one later.
Yeah I probably should have clarified that; although I'm calling it a crusher, I'm not expecting much beyond a firm grip, maybe a little bit of penetration (giggidy) especially as you could get some pretty strong top armour for not much weight.
It's going to be a threaded rod on a motor to power it, don't know what motor yet but I'll play around with some options and see how it goes.
I was never a fan of the disc of doom (or whatever it was called) in the RW arena, but a spinning disc coming up from the floor could be interesting. It would certainly bring an element of control back to proceedings, as roboteers would have to make sure their driving was up to scratch to avoid unnecessary damage but as Dave says, 2kg might be a bit too much. If I remember rightly, Hornet's disc weighs 1.8kg and look at what that can do at speed to featherweights nevermind kilobots :lol:
ill have a 1mm carbon fiber lid Jamie I'm sure you'll get through that! if not ill put cardboard on it lol.
hows about kill saws instead tom? Ive got some horizontal milling cutters you could use, spin em up with something and have them shoot out the floor battlebots style?
You allowing magnets tom? since your floor's steel...
Ye have magnets if you want.
In between fights you would want to be able to activate or reset the pit from outside the arena. Probably during fights as well.Quote:
Originally Posted by xtreme
dave i got loads of fridge magnets got coca cola magnet n magnet of a dog, stick them in your kiloweight then i dont owe u a tenner:)
Anyone making any progress with theirs?
After coming across some motors that might be good for this class - if a bit slow - I might knock one together from spare bits and take it to an event at some point...are there any plans for when you might be able to use the arena for the first time?
Such a shame I no longer live in the UK. I've got some wood (don't laugh!) hanging around which could make the perfect armour and plenty of old motors and RC cars. I'm pretty sure, what with my young 14 year old mind, that I'll be able to make something decent. I've been building all sorts of crap since I was 5 or so so this should be childs *cough* play.
Not like I'd be able to compete anyway... If only my school were more interested in anything at all! :rofl:
I've convinced a classmate who also builds things and sticks 24v batteries onto the tiny little motor jobbies you get in phones to make them vibrate for the hell of it. I can have my own little mini-competition ;)
Looking forward to seeing some of the bots being built... I want to see if they look as bad as my chunk of wood!
I am looking forward to the arena being finished and seeing the first few battles I€™m like most roboteers waiting for the arena to be completed, and then will probably start on a little project myself. I can see this size format taking off, as it can be run almost any ware at little cost this could be the future. :D
Still just need the polycarb and the basic arenas done. Doing the polycarbs only a couple of hour job. Just going to wait until a few of us have working bots before I get any polycarb, dont want to have to find somewhere to store it and it get all scratched before we even use that arena. Prob next month or so should have some bots done.
Well that's going to be slightly confusing, isn't it? If most people are waiting until the arena is made to make the bot's then... Haha.
Anyway, since I live in Spain, I'll never be able to compete for real, so I'll be hacking on of these apart: http://www.oneswitch.org.uk/IMAGES/1/tumbler0.jpg for the correct radio (skid steer) set. I'll be upping the motors most likely, and 6 or so mm thick wood for amour/chassis.
Wow. What great timing. My dad just brought in two old CD drives, I'll see what motors are inside. :twisted:
They'll probably be brushless or stepper motors so probably not that useful, to fast, too little torque.
Most people will rewind them for use in rc planes and helicopters like this: http://www.bavaria-direct.co.za/index.htm
Got my last exam on Wednesday so hopefully will be able to make a start on some kilobot stuff after then. Need to sort out Kaizer first and service Drumroll but all being well I'll have some part-constructed kilobot with me for the Robots Live Edinburgh event in June. I highly doubt it'll be running then but should be a chassis at least.
@ Jordan: I've taken apart varios disk drives, the motors in them are really nothing special. I could only open one because my dad realised (after I asked him if he was sure) that one of them worked fine, just old as all. The one I opened had 3 motors, one for the tray, one for spinning up the disk, and another which I can't remember what it did, but it was identical to the one powering the tray.
The two identical ones are actually pretty powerful for their size, I'll have to find out howmany volts they're designed to run at, they're a possibility. If not I'll add 'em to the stash of god knows howmany old and new and bodged motors I've collected over the past few years.
Sadly, the motor that drives the actual disk is a stepper motor, as you say. Masses of wires, I would hack apart the bit of circuit board that the wires were attatched to but the bit I need is right in the middle, so, that's a no go.
I have around 60 spare euros hanging around, so I'll go and buy some fresh motors. Old RC model motors are a little simple and... the same now days. ;)
How many volts the motors run at needn't be a barrier, I'm trying to get a kilobot done atm using some 28 volt ex-military motors :proud:
I have no reaql idea what to do for weaponry though, I don't trust my 'engineering' with spinners so I may end up with a servo lifter type device on the front, or possibly just some sufficiently evil looking eyes.
Craig said: I am looking forward to the arena being finished and seeing the first few battles I€™m like most roboteers waiting for the arena to be completed...
Me too. I was at Robogames in San Francisco a couple of weeks ago and spent a fair bit of time fighting 3 lb robots in an 8 foot by 8 foot arena. They have some serious 3 lb spinners and battles can be very spectacular. The crowd can get up very close [good plexiglass or whatever] and a fight between 3 pounders is as good as one between bigger classes when you are really close to it.
Here is a video of a couple of 3 lb robots fighting in the 8 x 8 box:
http://www.youtube.com/watch?v=5SNba6eg ... re=related
Anyone know of any small (2A-5A) RC speed controllers that can be run from a nominal voltage of 3.6V? And that aren't too expensive?
I've made two 3.6V battery packs up from an old 7.2V Nicad pack I had lying around to provide power for a kilobot because a) they weren't really doing anything and b) I've already got chargers for them so it would save me having to buy new gear. The only problem is that most speed controllers have a low-end voltage input of 4.8V minimum. There are some speed controllers on Technobots that run lower than 4.8V (some of the Pololu range) but they're designed for logic input and I don't know if/how they can be modified to take an RC input. If I can't find anything I'm considering resorting to small-scale servo switch units.
As for the kilobot itself, I've postponed the crusher design for now as it was going to be too costly for a first attempt so I've decided to go simple-ish and classic with the design. Recognisable classic actually, in the form of a Cassius II replica (minus active spike). Pretty much settled on drive motors, wheels, battery, weapon power (a bad-ass 20kg/cm servo weighing in at 160g :twisted: ) and chassis shape/materials. Going to make a cardboard cutout and try the parts out for size in that first. If I opt for the servo-switch method, I'm looking at a total cost of £45-£50 which is pretty win for something which, on paper, should be moderately decent. And if it gets smashed up, then it won't have been too much of a costly endeavour (in keeping with the original robot design, the armour will most likely be polycarb)
OK, just clarification on some of the rules ideas of this class.
What is the requirement for failsafes?
For antweights the weapons need to failsafe but the drive does not as a running robot doesn't create much of a risk and also servo's do not always go dead centre when they failsafe so will keep creeping. I think we all know what the rules are for feathers.
To me I think that the weapon failsafe would be sufficient for this class having seen the como drills performance, nice and puchy but put your foot in front of it and it aint doing any damage. I think this comes into the 'you can always put your foot on and crush it' category.
I also means I can use the 'compatible' spektrum receivers on these which would seem to make it a lot cheaper to put together a few kilobots considering they are about £30 cheaper that the genuine spektrum receivers.
Andy
Any news on how the build of the arena is going? When might we expect to see it, and 3 lb robots, in action?
I've been putting together a little machine over the last couple of months, I'd seen the idea of a 3lb class and reckoned it would be as good a weight as any to restart on, there's many nice components designed for hobbyists and 'conventional' robot builders at this size.
http://a.imagehost.org/0502/Untitled-1_9.jpg
It's a nifty little machine and can climb over pretty much anything (note the plow goes 360° and if you only want to go forwards or back you can happily somersault along). Still rather a lot more to do, including cut and fit a titanium plow, it only weighs 650g at the moment.
http://www.youtube.com/watch?v=jn8JAMcWbQQ
I look forward to more arena news, especially if it involves an obstacle course!
Was wondering where you'd went Ewan, it's been a while since I've seen a post from you :P
Nice looking little kilobot there! That's probably one of just a few properly active ones around just now, most of the designs people have been discussing haven't yet fully materialised, mine included.
Those are the Lego Technic tracks aren't they? Just curious what you're using for rollers/hubs/whatever-you-want-to-call-them in place of the plasticy yellow rollers that are part of the Technic track kits, as I was contemplating making a tracked kilobot out of them but deemed the yellow bits too much of a weak spot for being brittle/not very robust.
In fact, a general parts breakdown would be cool if that's okay? Motors, controller etc? :)
They're actually the tracks from this kit http://www.inertialabs.com/srv.htm , still plastic hubs mind but somewhat tougher than lego (and given inertia labs is trying to sell them to the military, they're good enough for me!).
The motors are some of these http://banebots.com/c/MS-16XXX-050 , speed controllers are some of these http://www.robotpower.com/products/scor ... _info.html and all of it is run at 11.1v (a big fat 1000mah pack in fact, am probably going to run a smaller 14.8v pack for combat/short competitions, it lasts for 40mins of driving as of now). This build has been my first foray into carbon fibre and it's great stuff, tough as nails and yet cuts with the band saw like butter (has thoroughly blunted my countersinks though..).
Am liking the look of yours so far, was always a cassius fan tbh. What are you powering the arm with, if you've yet decided?
Hey Ewan, long time no see :D
Last time I spoke to you in person was Exeter 2007, man its been a while.
I really ought to get to making my kilobot, these look awesome :)
Ooh I forgot about the Scorpion Mini controllers, they look quite nice and compact. Might well consider them if I end up increasing my battery voltage.
What I'm looking at for the flipper so far is a big heavy-duty servo. This one from Giant Cod reportedly has 20kg/cm of torque (although that is at 6V):
http://www.giantcod.co.uk/9805bb-towerp ... p-177.html
I'm going for a servo with that much torque in the hope that it will be quite similar to having a pneumatically powered flipper. To get a speedy flip and not just a push-up, I'm going to mount the linkage connection between the servo and flipper quite near to the flipper pivot point so the leverage ratio will be quite high. But hopefully with the high torque from the servo it will mean that there will still be enough power in the flip to chuck opponents and right the robot.
That, and the fact it's only £12 :lol:
What do people think to lego power functions as drive motors?
According to here the Xl motors have 40 Ncm stall torque, 220 ish rpm (no load, 9V), draw 1.8A when stalled and weigh about 70g and the medium ones have 11 Ncm stall torque, turn at about 400rpm (no load, 9V), draw 0.9A stalled and weigh about 35g.
I think they are both under 2 in all dimensions and you can probably do something about mounting them using the holes or glue/solvent (pretty sure the majority of lego is made from abs.)
http://cache.lego.com/images/shop/pr...00-xx-12-1.jpg
Yeah Dave get building! =p at this rate we'll have a featherweight scale tournament by the time this arena is ready, I look forward to it.
The scorpions are very nice controllers, they've barely got warm after 40 minutes of driving about even packed together relatively tightly.
I'd imagine with a big enough servo you'd be able to pull it off (you've probably seen some of the antweights doing just the same thing), it's worth considering overvolting the servomotor to get some extra torque and speed (one thing I'd be wary of about the servo you've linked is the apparent lack of metal gears/no metal output stub to mount on which may lead to breakages if you're running at maximum torque). Of course if you overvolt you'll need to bypass the servo control board which likely wouldn't like it.
The lego motors look alright, certainly usable with those torque ratings although you can get better for the same weight. Do they have position feedback as the four-strand lead might suggest? =s
Great minds eh??Quote:
Originally Posted by k_c_r
Got two of those sat on my kitchen table. I've been testing these to see if they can be used effectively. They work just fine of a 7.2v lipo but are still noticably slower than you would want for a flipper although you could get something quite respectable in terms of tip speed with various mechanisms and a longish arm.
I'd like to run these at much higher voltages so will gradually increase the cell count until i get to 14.8V. Quick inspection of the internal electronics doesn't make me think this is too unreasonable. All the capacitors and stuff are rated for it, just depends on the little integrated circuits which i can't identify and the motor windings. The motor appears very similar to the Como Drills 918 which we are using for drive. It'll either end up as a melted mess or it'll work. Generally the results of this type of stuff is relatively instantaneous and very definite :proud: .
Anyone looking for a nice cheap speedo could consider doing what some of the antweight guys do and stripping the board out of these. Simply take out the potentiometer and measure the mid point and replace with two fixed resistors. ATM I'd say dont run them over 7.2V but I'll get back after I've wired up an 11.1v lipo and 14.8v lipo.
Andy
That's excellent Andy. Supplied data is one thing but it doesn't beat real results from real testing. Anything more you learn about that model of servo would be welcomed :)
I'm definitely not expecting fast-flip speeds, but as you say, with a suitable ratio I can hopefully get something reasonably effective. For a first kilobot it will certainly be a learning experience!
Ewan, the lack of metal gears caught my eye too and it is something that I will be monitoring. Once it's all built I think several test flips will be in order to see how the gears stand up. If they aren't up to the task, I think there are less powerful servos (still in the region of 12kg/cm) on the Giant Cod site that have metal gearing, so that's a back-up for the moment.
Just want to say too, although I've not built much so far, what I have done has taken less than an hour of construction time. I thoroughly enjoy featherweights but it's nice building something smaller that doesn't require as much 'heavy-handed' tooling (for lack of a better description). Whether the construction is strong enough to stand up to some of the brushless spinners that are being designed/built remains to be seen :proud:
It's looking very good so far I must say :)
I've had some good results from using slightly overvolted servos in front hinge flippers at antweight level - you've seen Jigsaw before and the mechanism on that works quite well despite having no real design thought at all going into it, although I'd advise beefing up all parts of the linkage including attachment points and hinges because if you do design it well and optimise it for maximum flip, there's a good chance the mechanism might have quite a kick in it towards the end of its travel or even lock up. Unless you model the lengths beforehand in CAD or card (which I anticipate you will being a better designer than me, heh) trial and error is the key to getting it right, and I had a fair bit of error :P
Lego released the protocols that they use http://www.philohome.com/pf/LEGO_Pow...ns_RC_v110.pdf
Aparently the IR reciever can support pwm but I it's where 4 bit binary number is sent with 0001 as full forwards, 1000 as brake and 1111 as full backwards.
I would probably have to buy one to test what wire does what and whether anything has to be done to the radio transmitters signal to make it work.
:rofl:Quote:
Originally Posted by joeychevron
Me model the lengths in CAD? I'm useless at that stuff! I can make simple CAD images for getting an idea of how a robot will look but that's about it :proud:
No the flipper linkage will indeed be a whole heap of trial and error; pretty much a case of
*drill hole here* *test* *not that great*
*drill hole there* *test* *hmm, a bit better*
Lather, rinse and repeat
It was actually seeing Jigsaw's mechanism as well as some vids of it in action that made me want to make a front-hinge flipper and then a combination of being a Cassius II fan and not wanting my robot to look like a rip-off of Jigsaw/Envy that made my mind up about building a mini replica of Cassius II 8)
so instead of making it look like another robot and people saying hmmmm thats a copy your going from the start 'guys this is copy' so no-one can saw anything hahahahahah
Hmm yeah, having just re-read that it doesn't quite make sense!
Although I guess I could argue that Jigsaw and Envy are still active robots whereas Cassius II hasn't fought since 1999/2000? So at least that way I'm making a replica of an iconic robot from the past (not that there's anything wrong with Envy and Jigsaw :)) rather than copying a successful modern-day robot
OK, now had a look at it and 'run' it at 11.1v. Not a big molten mess but did release the magic smoke.Quote:
Originally Posted by k_c_r
I've now taken it apart and it seems that the only damage is to the track from the live feed and a shattered signal diode. The rest of the board actually seems to be ok (meaning it hasn't burnt out to any visible extent). Beefed up the track with a bit of wire and now need to get a few appropriately sized diodes and play about with some resistors etc. It's actually quite nice bacause the board is big enough to see what is going on rather than trying to work under a magnifying glass all the time.
Andy
replaced the diode and the servo works just fine. Seems that a play with some different diodes or some in parallel may pay some dividends.
Andy
sorry this is out of the blue, but I have a idea about the arena. (some ones probably said this but I can't be bothered to read through all of the pages so I will say it anyway)
I think there should be a quite steep hill going up to the pit button or spinner button.
or you could have a 1 or 2cm gap in the arena to get to the pit button or spinner button or even a flamethrower button. :twisted:
you could have a shallow pond or puddle to stop the non water resistance robots and incorage amphibious robots.
you could have a button on the ceiling which drops large ball bearing balls onto the other robots this might encorrage flying or jumping robots if they are legal. :?
I also thing there should be more completly autonomous robots in the arena so you could let fully autonomous robots have a larger weight limit.
These ideas don't have to be used but I think they are good ideas.
Ah, you should check out my videos!Quote:
Originally Posted by daliad100
www.youtube.com/ochayedonald
incidentally, with the rechargable batteries from Lego the heaviest weighs 805g-ish.
Thought I'm not sure an entire lego construction would stand up to metal constructions!