Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: elobire on January 08, 2009, 11:44:32 AM

Title: first robot
Post by: elobire on January 08, 2009, 11:44:32 AM
hi im only 14 years old and i building robots is allways what i have wanted to do.
i am looking to build my first robot but i only have a small budget of £10-15, will this be enough?i have managed to scavenge a few bits and pieves from some old rc cars i have which iclude-2 6v moters and 4-5 other unknown motes and some remots and controll boards.
 i have built the "real robot" magazine robot and that worked out fine will this be that easy?
will i be able to make my robot in a £10-15 budget and does anyone know what the best V DC moter would be and where can i get them?
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thanks Elobire :)
Title: Re: first robot
Post by: frodo on January 08, 2009, 12:01:01 PM
i think the £10-15 is a little little. try to aim for around £25-30 and scavenge what you can. servos are better than motors but motors are fine. how are you programming, PIC or AVR?
Title: Re: first robot
Post by: elobire on January 08, 2009, 12:15:12 PM
i think the £10-15 is a little little. try to aim for around £25-30 and scavenge what you can. servos are better than motors but motors are fine. how are you programming, PIC or AVR?
sorry i have no idea how to do that or what it really does.
i gues i should have done a bit more research before posting.
i might be able to increase my budget to around £25-30 but i need to know what to get before i go out and buy things i dont need.
Title: Re: first robot
Post by: frodo on January 08, 2009, 12:23:37 PM
i think what would be good to do for about £25 is the $50 robot tutorial. that will explain everything. i'm sort of new at this aswell but you'll get the hang of it.

the tutorial page is:
http://www.societyofrobots.com/step_by_step_robot.shtml (http://www.societyofrobots.com/step_by_step_robot.shtml)

the english price list is (if you are in England, i'm just assuming here):
http://www.societyofrobots.com/step_by_step_robot_british_parts.shtml (http://www.societyofrobots.com/step_by_step_robot_british_parts.shtml)

by the way, a motor is electromagnetic whereas servos are controlled by either digital or analogue gears and electricity.

Motor (below)
Servo (bottom picture!!) lol
Title: Re: first robot
Post by: want2learn on January 08, 2009, 02:45:30 PM
Hi,
Can you solder?

Actually building a robot is a lot more involved than building the 'Real Robots' one because it was essentially a kit that came piece by piece with a magazine.

£10-15 is a little low for a full robot, BUT, it's enough to build the basic circuitry for the $50 robot (if you can solder).
While you're building that you could be saving for other parts. One of the great things about Admins $50 robot tutorial is that you don't specifically need to use fancy materials if you can't get or afford them. All you really need is a little ingenuity, time and patience.

As for servos and the likes, you can salvage these from r/c stuff too (in cars they are normally used for steering.
The difference between a motor and a hobby servo is that a motor will need a circuit to interface to the microcontroller (the microcontroller can't supply enough power to it) and will more than likely need a gearbox (or really tiny wheels). A servo is a motor with a gearbox and some circuitry to drive the motor already wrapped up in a nice little box. There are other differences but at this point i wouldn't worry too much about it.

If you do choose to follow Admins tutorial I would try to stick to servos as this will make it easier. If you can't get the hitec servos recommended just post a question asking if the ones you have seen are suitable (before buying them).

You'll need to buy a programmer too, if your computer has a serial or parallel port you could save a bit of money on the programmer by buying/making an older version << thats for the avr microcontrollers and possibly one reason avr uControllers became really popular, i have no idea if you can buy or make a cheap programmer for PiCs or any other chip producer.

The problem you're facing now is one that many have faced before: Starting from nothing.

It costs money
It takes time
It requires patience
AND PERSERVERANCE

Best of luck
Title: Re: first robot
Post by: cooldog on January 08, 2009, 03:27:13 PM
As for servos and the likes, you can salvage these from r/c stuff too (in cars they are normally used for steering.

rc cars don't usually use servos for steering
Title: Re: first robot
Post by: frodo on January 08, 2009, 03:54:24 PM
As for servos and the likes, you can salvage these from r/c stuff too (in cars they are normally used for steering.

rc cars don't usually use servos for steering
what do they use instead then?
Title: Re: first robot
Post by: Razor Concepts on January 08, 2009, 04:24:39 PM
Actually servos were first created to steer hobby grade RC cars. Robot guys just figured they would make a cheap gearmotor. But the toy RC cars don't use servos.
Title: Re: first robot
Post by: cooldog on January 08, 2009, 08:04:02 PM
As for servos and the likes, you can salvage these from r/c stuff too (in cars they are normally used for steering.

rc cars don't usually use servos for steering
what do they use instead then?

usualy a motor with gears that is programed to only move for a certain distance
Title: Re: first robot
Post by: madchimp on January 08, 2009, 10:55:34 PM
usualy a motor with gears that is programed to only move for a certain distance

toy R/C cars do it that way but every hobby grade R/C car I have had uses servos there is quite a difference in the quality of the toys versus the hobby R/C equipment. Just something to keep in mind when searching for things to cannibalize for parts  ;)
Title: Re: first robot
Post by: marc on January 09, 2009, 07:31:20 AM
well before I started with robots I was into Rc and the most cars use normal servo and even if you
buy a cheap one there is a change that that car has a mini servo instead Nikko (n I don't know if you know that brand but it's populair in holland ) cars have servo's
with the really cheap chinese made cars there is a mini motor in plastic that will do the steering or a mechanic speedregulator will do it.
i'm just into robots but I know things about rc cars so if you have quistions just pm me

good luck

Marc
Title: Re: first robot
Post by: elobire on January 09, 2009, 09:45:07 AM
Hi,
Can you solder?

Actually building a robot is a lot more involved than building the 'Real Robots' one because it was essentially a kit that came piece by piece with a magazine.

£10-15 is a little low for a full robot, BUT, it's enough to build the basic circuitry for the $50 robot (if you can solder).
While you're building that you could be saving for other parts. One of the great things about Admins $50 robot tutorial is that you don't specifically need to use fancy materials if you can't get or afford them. All you really need is a little ingenuity, time and patience.

Best of luck

thanks for the reply
yes i can solder a bit im sure i will need to be good at it for my robot to work properly.
a programmer is to tell it what commands to do right?, do you know where i can get one from.
i think il have to come up with some more money if i want to start this properly
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thanks again- elobire
Title: Re: first robot
Post by: marc on January 09, 2009, 11:08:06 AM
I think I have the same problems as you, I also need a microcontroller>>>programmer
I think I'm going to buy the roboduino it's cheap and good ( at least that's what people say)
you said you had some stuff of a rc car can you tell me what parts maybe I can help you

grtz

Marc

Title: Re: first robot
Post by: want2learn on January 09, 2009, 12:55:24 PM
If you do go with Admins tutorial, you can buy the electronic components first. Practice soldering on a piece of veroboard you wont need (there's bound to be some spare) and use the header pins as they'll take a bit of abuse. This in itself will give you something to do while scavenging and saving for the bits you don't have yet.

As for programmers: You write the program for your robot on a computer. This is then converted by another program (compiler) into stuff your microcontroller can understand, this program along with the programmer http://www.adafruit.com/index.php?main_page=index&cPath=16&sessid=cb89cb9835af48152190cc971ceb203f (http://www.adafruit.com/index.php?main_page=index&cPath=16&sessid=cb89cb9835af48152190cc971ceb203f) transfer the converted (compiled) program to your microcontroller.

I know that link is for an American/Canadian site but they have a good choice and are really friendly, They've given me advice a couple of times even though i didn't buy anything (on those occasions). The fact their products are competitively priced is a big bonus ;D

 You don't have to come up with more money immediately,  just do the things you have parts for wether they are               scavenged,   borrowed (maybe permanently ::)) or bought.
I know doing things slowly can be a real big pain but you have an advantage here, it means you are more likely to take your time doing things which in turn means less mistakes and absorbing more of the information available/necessary at the time

 
Title: Re: first robot
Post by: emusan on January 14, 2009, 03:51:37 PM
Hey there, I'm also working on my first robot at the moment. It cost me about $35 in parts(about 27 euro's). To move it I'm using 2 pager motors with an H-bridge, you can find tutorials for all that stuff on this site. For sensors I'm using CDS photo resistors(like in admin's tutorial). I'm using an AVR attiny as my microcontroller and an AVRisp as a programmer(I've already got some experience with AVR, just not in robotics), I recommend using AVR's because they are SUPER cheap compared to PIC's and others. My chassis is just going to be the circuit board(it's going to be quite small). Most of the parts can be found on electronic-goldmine, its all really cheap compared to other robots.