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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.
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.
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.
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
Quote:
Originally Posted by lowes3
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.
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.
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
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
http://www.youtube.com/watch?v=9ibaEOpYPAg
There are more episodes if u look around!
:proud:
why steer clear of the electronize?Quote:
Originally Posted by psycho_fling
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.
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
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.
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.
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
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 :proud: ) 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 :)
Steel difficult to work with? Not at all. Some steel angle or box cut with a hacksaw and bolted together with armour bolted on is not difficult.
Electronize a pain to set up? Plug them in and off you go. Took me a half hour to set up a sabertooth and even then they aren't as robust as an electronize. I've gone through several speedos and still found the electronize to be the only reliable ones I've come across able to take the ratings continuously that they specify.
I have never heard of nor seen a ladder used in any way for a robot chassis and can't really imagine how it would.
To be brutally honest, your best bet for finding out whats what is not to write questions on here but get along to an event and ask questions there. You will learn far more in an hour or two at an event than several days on the forum. Believe me, I know!
I see, well, I'll be quiet then. I can agree on Electronize being super easy to install, though, took minutes.
Edit: I'm only going by what my father says on steel being hard to use, he says he has had many problems with steel, angle grinders just not doing anything, wrecking the discs and just making a mess, a metal saw as you say would probably be a better bet. I'll pick his brains in the morning. :)
steel isn't particularly hard to cut with an angle grinder if you use a correct disc but i doubt anyone would have the patience to cut a sheet of steel with a hacksaw :rofl:
alex
When working with an angle grinder i'd recommend using good quality discs. Not the ones you find in a pound store, buy some from screwfix or similar. Take the cut nice and slowly, use the weight of the grinder and don't force it down as you will wear down the discs in seconds. It also sounds silly to say but make sure you are using a metal cutting disc (around 3mm thick) and not a grinding disc (about 6mm thick).
I found that using a small 115mm grinder will take a long time with a few mm thick of steel. A 230mm grinder will however go through it like butter. I tend to use my big grinder for cutting and the small one for grinding and those small tricky cuts.
Most importantly, make sure you wear protection! Goggles, gloves and ear defenders are essential.
We use pretty average quality discs, but we have a large diamond edged disc and a small one (large and small grinders), would they be any good? They don't have a rough edge as such, but harder disc for harder metal?
I'll have a look around for some decent discs too, thanks.
just make sure you use metal discs on metal and not stone cutting discs :)
also if you get some quality 1mm discs will help as it is 'pushing' less disc through the metal
what about motor mounts? do people use the ones from robo challenge.
Yeah I believe they're used quite extensively. The Robo Challenge mounts are a great low-cost and ready-made solution for fitting drill motors into a robot.
I've used motor mounts in the past but now I just sort out the mounting of them myself. This basically involves cutting the gearbox shape (which is like a pair of 'D's back to back) into whatever material I'm using for my chassis and securing it in place with a mounting plate that comes as part of a cordless drill (it screws in in between the chuck and the spring that controls the clutch action). It's not too complex a process but for a first-time build, I would just go for ready-made mounts. Keeps things simple.
Hi Adam we are based in Gateshead pm me your pnone number and I will give you a call :)
Clive