first robot questions :)

[lowes3]

i have never built a robot before but have wanted to for quite a while now. i have some 24V 44W motors would these be suitable for a featherweight? i have seen alot of people use drill motors, would these be a better starting point?
i was thinking about a simple 'rambot', 4wd, that can run eitherway.

i also have no idea how to build a frame for the robot if anyone could give some suggestions.

[elobire]

Re: first robot questions

im also building my first robot (finishing it off now), so i cant really talk from experiance. what i do know is that drill motors will be what you should use. i also had 2x 24v motors which i bought without thinking. i soon realised it would be too complicated to use them in a simple robot.
you can get the wheels, motors and mounts from robochallenge:
http://web.me.com/robochallenge/Robo_Ch ... nical.html


hope i was of help,other people should be able to give you better advice on the speed controllers so i wont bother confusing you.

[Ellis]

Re: first robot questions

Drills are a good starting point, they have plenty of power, they're dirt cheap and come with good gearboxes. As for a frame, I'm guessing you don't know how to weld, if you're not sure how to start a chassis. I'd suggest a ladder, for again, a cheap but if well made, decent chassis. I am using parts from an old ladder for my first bot, they're strong (well, not the strongest, but with supports and thing they're great) and are very easy to make use of, very light too.

But, you should be thinking of motors, speed controllers, radio gear and batteries before a chassis, you'll end up with a chassis too small or larger than necessary if you do it the other way round.

I'm not being very helpful here , have a look around the build threads and the featherweight threads, there are loads of first time bots being made, and lots of very helpful suggestions.

[lowes3]

Re: first robot questions

i was thinking of 4 12V drills from argos, but i wouldnt have thought theyd be very powerful. but theyd be ok for a featherweight?
nope i dont know how to weld at all steel ladder frame? polycarbonate would be no good?

i thought a Sabertooth dual 25A speed controller, would that be able to supply 2 drill motors each side, so 4 all together. i was planning to build it on plywood or something first before i built it properly.

no youve been very helpfull thanks for your help

[elobire]

Re: first robot questions

i was thinking of 4 12V drills from argos, but i wouldnt have thought theyd be very powerful. but theyd be ok for a featherweight?
nope i dont know how to weld at all steel ladder frame? polycarbonate would be no good?

i thought a Sabertooth dual 25A speed controller, would that be able to supply 2 drill motors each side, so 4 all together. i was planning to build it on plywood or something first before i built it properly.

no youve been very helpfull thanks for your help

the drills from argos would be more than powerfull enough. either get them or the identical motors from robochallenge,depends if you want to save time ripping the drill apart.
building it on plywood is a great idea, done something simular with mine (although i did it because i was bored waiting for parts).

also as relentless said, check build diarys and threads in the featherweight section, you will learn alot from other people asking the same questions that you are.

[Ellis]

Re: first robot questions

You'll be surprised, drill motors pack quite a serious punch, 4 of those and you'll have a very fast and powerful robot on your hands, people often use just 2. I'm not all that good with ESCs, but I am using 2 30a Electronize ESCs (cheap and cheerful), some love them, some hate them, I don't have any experience with others so I can't really give a real opinion, all I can say is they work good for me.

Steel ladder? I've never head of a ladder (I mean fullsize ladders) that isn't aluminium, some 2 step ones are steel, but aluminium is very very light, quite strong and I'm sure you can find an old ladder from somewhere. You'll have major problems using steel, it's a fantastic material but horrible to work with without the right tools. Lots of people on the forum do have the right tools, if you give precise measurements then I'm sure they'd be happy to cut you a piece or two.

Obviously you'll need a radio system, I'm using the Planet 5 2.4ghz transmitter/reciever set (quite cheap), I don't have much experience with others either but I can say it's been fantastic, and very very easy to set up so far.

[psycho_fling]

Re: first robot questions

Welcome to the forum and a good choice

yeh polycarbonate is a good idea were you thinking for armour???

with regards to speedos (speed controllers) id steer clear of the electronize save your self some trouble and for a dual controller much better and when you get more into the sport you will want something more precise

alex

[lowes3]

Re: first robot questions

yeah for armour and for the base and maybe chassis?
what speed controller would work with 2 12V drill motors on each side, so 4 all together? ive heard of a sabertooth dual speed controller. i dont really want anything too expencive for my first build.

as for radio gear i was thinking of using my old futaba radio gear from a model aircraft. i know it will probly be an illegal frequency for battles but i would just use it to see whats what and if i could actually get the robot working :P

Adam

[rallikas]

Re: first robot questions

http://www.youtube.com/watch?v=9ibaEOpYPAg
There are more episodes if u look around!

[elobire]

Re: first robot questions

Welcome to the forum and a good choice

with regards to speedos (speed controllers) id steer clear of the electronize

alex

why steer clear of the electronize?

also dont get the transmitter from giantcod, i had it for about a week and it started breaking. go with the planet 5, they seem to be the best thing for a low budget.

[psycho_fling]

Re: first robot questions

basically because in my experience they offer poor control and it is hard to get a pair to work effectively, plus £70 doesn't seem cheaper to me

[RogueTwoRobots]

Re: first robot questions

Electronize aren't the most precise of controllers, but they do a good job for what they are and are fairly robust. You'd need one of each side of the robot. They can be a pain to get working together but two important aspects are: the trim levers of a radio control transmitter (they allow you to make small changes to the positioning of the stick/speedo) and the little adjustable speed control dial on the controller itself (you can use this to regulate the output of the controller i.e. 50% speed, 75% speed etc).

Most DC motors tend to spin slightly faster in one direction than the other, and since you'd be putting two back-to-back in a robot, the robot won't drive forward in a straight line because one motor is going faster than the other. But you can use the trims and the adjustable speed dial to fine-tune your Electronize setup to a degree such that it will drive in a straight line. If you're prepared to spend a bit of time fiddling about with these aspects, you'll end up with a setup that is relatively simple to control.

A pair of 15amp Electronize controllers combined with a mixer (a device that allows you to 'mix' the two controllers so you can drive your robot with one joystick, like a computer game) will cost the same as a dual controller that will have built-in mixing, so it's really six and half-a-dozen as to which one you choose. I've never used the Sabretooth but from what I've heard, the Electronize controllers seem to be able to put up with more abuse (both physically and electrically) so wouldn't be a bad choice to begin with if you wanted to.

[RogueTwoRobots]

Re: first robot questions

Additionally, the first motors you refer to sound a bit under-powered at 44W, compared to drills which I believe to be around the 75W mark (although comprehensive, definitive data on a cordless drill motor isn't something that flies about a lot so I can't be sure on that figure).

If you go for two drills on either side, so a 4WD rambot, I would aim to have a controller that could handle 30A per side. Any 4WD machine I have built has used 30A Electronize controllers and I've never had a problem with them. The Sabretooth does 25A per side but I couldn't be sure how reliably that could handle surges in current from four drill motors. But again, I've never used the Sabretooth so I'm just going on assumption here.

Lastly, I see you're from Newcastle-upon-Tyne. Maybe send a PM to one of the Team Toon members. They've got a few featherweights and are from Gateshead so they could maybe show you some of their machines to give you an insight to the workings of a featherweight. Failing that, try and get yourself along to an event, where you've be able to check out a lot of machines, ask a lot of questions and learn a helluva lot more than what we can tell you here. The UK featherweight championship competition was held in Newcastle last year as well, would've been ideal! It's a bit further away this year though, down in Somerset.

[lowes3]

Re: first robot questions

it sounds like the speed controllers are the fiddely bits to set up. ill probly just have to buy some and build it up, then have a fiddle about. i have had loads of RC things in the past but none that i have had to set up speedos really.

ill probly just go for drill motors then, the 44W motors that i already have are quite chunky as well which probly isnt good for a small robot.

Electronize controllers seem to be the forerunners at the moment for my simple first bot

i didnt relise there was anyone near me building robots. that would be great if they could show me anything, or give any advice. ive been looking at the events that are happening soon but none of them seem to be under 5 hours away from here was there an event in Newcastle last year?? that would have been perfect for me to get some info.

Adam

[RogueTwoRobots]

Re: first robot questions

Ach, they're not too fiddly to set up in all fairness. You can literally take them out the box, connect some wires and you'll be good to go. The fiddly bit only comes in to it when you need to make small adjustments to get it running the way you want it, which will probably be different to the way it runs straight out of the box. It's worth it the effort though to take the time to fine-tune it.

The UK Featherweight Championships, which is the big featherweight event of the year (full combat, spinners allowed) was held at the Centre for Life in Newcastle last year as part of the Maker Faire exhibition. I think the date was 14th/15th March. That's one of the northern-most events we've had in a while. More recently there was a Robots Live event at the East Fortune Air Museum near Edinburgh with heavyweights and featherweights fighting it out. It was a more relaxed, exhibition-style event which can sometimes be better for showing people around as there is no pressure to get robots repaired quickly. But really, any event is a useful library (and a cool library ) from which to garner valuable information. Most events are a 5-hour trek minimum for us too, so I know the feeling, but keep an eye out in the Live Event section for any upcoming events that may be a bit closer to home for you