UK Kilobots - 1.362kg (3 lbs) Combat Robots

[RogueTwoRobots]

Re: UK Kilobots - 1.362kg (3 lbs) Combat Robots

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

[joey_picus]

Re: UK Kilobots - 1.362kg (3 lbs) Combat Robots

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

[daliad100]

Re: UK Kilobots - 1.362kg (3 lbs) Combat Robots

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.

[RogueTwoRobots]

Re: UK Kilobots - 1.362kg (3 lbs) Combat Robots

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

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
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

[psycho_fling]

Re: UK Kilobots - 1.362kg (3 lbs) Combat Robots

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

[RogueTwoRobots]

Re: UK Kilobots - 1.362kg (3 lbs) Combat Robots

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

[widow_twanky]

Re: UK Kilobots - 1.362kg (3 lbs) Combat Robots

Anything more you learn about that model of servo would be welcomed

OK, now had a look at it and 'run' it at 11.1v. Not a big molten mess but did release the magic smoke.

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

[widow_twanky]

Re: UK Kilobots - 1.362kg (3 lbs) Combat Robots

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

[Bodge Job]

Re: UK Kilobots - 1.362kg (3 lbs) Combat Robots

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.

[legorobotwars]

Re: UK Kilobots - 1.362kg (3 lbs) Combat Robots

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.)

Ah, you should check out my videos!
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!

[joey_picus]

Re: UK Kilobots - 1.362kg (3 lbs) Combat Robots

It wouldn't be totally impossible, a few antweights have used/still use Lego parts and survived spinner attacks (Lego wheels in particular are quite durable) but you might be pushing your luck with an alll Lego robot :P

[legorobotwars]

Re: UK Kilobots - 1.362kg (3 lbs) Combat Robots

Indeed they are Joey, they absord impact quite well! Oddly it seems better to have exposed tyres than not to!

Hmm, seems like an all-lego 'bot should be a catorgary of its own. Though I can vouch for these motors, they are good, powerful for their size and the speed of the Xl's isn't bad either. And as for the control, lego now have a speed controller...control thingy bob. So you have complete control over how fast the motors turn.

[Metal Demons]

Re: UK Kilobots - 1.362kg (3 lbs) Combat Robots

Here's the start of my kilobot - it's going to be a spinner, big horizontal blade driven off a brushless motor

[xtreme]

Re: UK Kilobots - 1.362kg (3 lbs) Combat Robots

Nick that looks sweet.

[Kenny]

Re: UK Kilobots - 1.362kg (3 lbs) Combat Robots

Bit of a update on 180 the chassis has been machined from a billet pics below







The chassis weighs on its own 250grams and with everything in side it weighs 450grams lol, disc , selfrighting arm and top armour to go and a wire up