Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: Judan on August 06, 2009, 02:41:59 AM

Title: Help for building my first robot
Post by: Judan on August 06, 2009, 02:41:59 AM
Ok well to start of  here are some pics of what im about to make which is a R/C robot with a arm on the front and camera on the back "for the momment"

(http://i26.tinypic.com/10shfzm.png)
(http://i27.tinypic.com/30kukw3.png)
(http://i25.tinypic.com/5pd2x.png)
(http://i25.tinypic.com/21myk94.png)
 (Made In wings3D)
Well basicly i would like any info on what i should do to make it etc like what motors for the back should i use and what servos for the arm and do i need a microcontroller or somthing simmiler (keeping in mind its R/C). Also i was wondering is their any other way to make it wirlessley controled than buying a 200$ r/c controler as i need to control about 4 maby even 6 servo's for the arm and 2 motors for moving around etc i had the idea of using a xbox 360 controler as i will only be using this wirelessly in my house so i dont need long distance.
And if anyone has any idea on how to control the claw using only one servo that would help heeps aswell...
Umm so ye just throw ideas at me and ways to do it etc, i greatly appreciate any and all help.

P.s If anyone is wondering how it will turn im puting omni wheels on the front
Thanks, Judan
Title: Re: Help for building my first robot
Post by: Joker94 on August 06, 2009, 03:31:10 AM
1) for the drive motors think about modifying some servos to rotate continuouslly.

2)you will need more than 1 servo for the arm you may need three or upto 5 for your arm going on the image you supplied.

3)Plastic is an easy material to work with to start.

and finally if this is your first bot and you are not going to start with the $50 bot, i strongly recomend you read these if you have not read them already, they help alot for this bot and the rest of the bots you make from now on.

http://www.societyofrobots.com/toparticles.shtml (http://www.societyofrobots.com/toparticles.shtml)
Title: Re: Help for building my first robot
Post by: Judan on August 06, 2009, 03:38:38 AM
Thanks ye i was looking for like what type of motor should i use for the drive as you can see ive thought up a little suspension system for the back thos black boxs are the motors umm what is a goo motor with good torque and rpm as its a larger robot the main idea for it is to like go open the fridge and get food and stuff like that probly also to scare people as the camera im geting is wireless and has a micro and speaker in it wich shoul dbe fun i have about 200$ to spend on it umm could you enlighten me on how to control 4 servo's and 2 motors and each having forward and backward movement cos i dont wonna spend 150 -200$ on a r/c controler as thats about how much controlers with 6 channels cost

P.s Thats Australian Dollers
Title: Re: Help for building my first robot
Post by: Joker94 on August 06, 2009, 05:29:29 AM
hey another aussie. ;D

How the easiest way to control 4 servos and 2 motors is through a micro crontroller, but i am not sure that is what you are after. And you will need a H-bridge to control motors.

Read this on H-Bridgeshttp://www.societyofrobots.com/schematics_h-bridgedes.shtml (http://www.societyofrobots.com/schematics_h-bridgedes.shtml)

Another thought is you could have a bluetooth module connected to your bot and instead or r/c you could drive the bot with a laptop or pc as you can see where your going with the camera. and you can get a resonable range blutooth quite cheap. There nay be better transmitters, trancievers out there that may be good for you want to do, i'll have a look, but blutooth is more simple, as you can plaug it into your computer via USB

Not sure of any good motors as i have never used a motor to propell my bot, always used servos. But have used simple dc motors for some experimentation i did.
Title: Re: Help for building my first robot
Post by: Joker94 on August 06, 2009, 05:36:05 AM
If you don't want to build a h-brige here are some pre made ones

http://www.sparkfun.com/commerce/advanced_search_result.php?keywords=h-bridge&search_section=products (http://www.sparkfun.com/commerce/advanced_search_result.php?keywords=h-bridge&search_section=products)

these are just examples, i am sure there is some where in Australia you can get them from.
Title: Re: Help for building my first robot
Post by: wil.hamilton on August 06, 2009, 06:14:50 AM
depending on how big you plan on making this also effects what motors you can use.  the GM series motors are easy to use and have wheels that fit right no them, but, they aren't terribly fast, but they do offer decent torque.

if you want something faster or more torquey you'll have to go for a more expensive metal gear head motor.
Title: Re: Help for building my first robot
Post by: Judan on August 06, 2009, 07:05:33 AM
ye using it via bluetooth sounds perfect seeing as im using the camera via internet aswell umm ill giv eyou guys the link for the camera to have a look at etc http://cgi.ebay.com.au/Wireless-MPEG4-Pan-Tilt-Internet-IP-Camera-Webcam-CCTV_W0QQitemZ350232273175QQcmdZViewItemQQptZAU_Webcams?hash=item518b786117&_trksid=p3286.c0.m14 and also base the robot on the size that the arm will need to be as the arm has to be able to grab the fridge door and opent he fridge then grab stuff out of it. 

also how many servos/dc motors can i controll via the blue tooth just curiouse

thanks for the quik replys to guys if i didnt have anyone to ask these things and get a good response back i dont htink id be trying this at all
Title: Re: Help for building my first robot
Post by: wil.hamilton on August 06, 2009, 08:47:51 AM
to open a fridge door you would need somewhat powerful servos, more powerful than the standard servo which puts out 50 oz-in of torque or so, you'll need to do calculations to figure out what arm geometry you'll be using which can then help you decide on what servos you should use.
Title: Re: Help for building my first robot
Post by: Joker94 on August 06, 2009, 04:50:48 PM
i think as many as you want if you have a good mother board and write up the code correctly. to open the fridge door you will need some really powerful  servos, and that may cost $100-$150 in its  self and aybe even more to get some servos that can handle that sort of load if you want 4 or 5,. You may suprise your self and find a bargin but it may get pricey

You may be able to yse motors it depends on how accurate you can get them to be as they are not designed for robot arms
Title: Re: Help for building my first robot
Post by: Judan on August 06, 2009, 06:16:43 PM
hmm i was hoping it wouldnt get to expensive :/ hmm ill make the base for it and leave the arm tilli have a good idea of what im going to do for it

also about the bluetooth thing could you send me a link or a price of one please
Title: Re: Help for building my first robot
Post by: gaurav.p on August 06, 2009, 09:34:22 PM
for bluetooth u need a rx and a tx ,for that bluesmirf is the best company in bluetooth modules according to me :P.and i hope u hav a bluetooth dongle for ur PC
here r  the links of the modules to be attached  to ur robot
http://www.sparkfun.com/commerce/product_info.php?products_id=582
http://www.societyofrobots.com/electronics_bluetooth_robot.shtml  (gr8 link for starting in blutooth robotics).


-gaurav
Title: Re: Help for building my first robot
Post by: Judan on August 07, 2009, 02:11:51 AM
hmm id need a micro controller to use the usb right so um how much is the axon in aussie dollers something around 125$ ?
Title: Re: Help for building my first robot
Post by: Joker94 on August 07, 2009, 02:45:29 AM
The axon would be $119.50 AUD.

If you want, you should be able to build you own MCU. For like 10 aussie bucks.

For components have a look at this site. Futurlec Australia

http://www.futurlec.com.au/ (http://www.futurlec.com.au/)
Title: Re: Help for building my first robot
Post by: SmAsH on August 07, 2009, 03:02:21 AM
The axon would be $119.50 AUD.
... whats the exchange rate at? that seems way too low...
Title: Re: Help for building my first robot
Post by: Joker94 on August 07, 2009, 03:09:21 AM
i use this site

http://www.xe.com/ucc/ (http://www.xe.com/ucc/)
Title: Re: Help for building my first robot
Post by: Judan on August 07, 2009, 03:10:34 AM
i do know the Us doller is down quite a lot therfore ours goes up its around 75 cents per us doller at the momment i think (only know these things as i need to buy motocross stuff of the net   :D)

also i think geting the axon would save me having to buy it later on anyway cos i want to make another atonoumus robot once ive finished this one and have it just roam around with the camera on and follow stuff if it sees somthing moving basicly just security in the house but more for anouying people lol
Title: Re: Help for building my first robot
Post by: SmAsH on August 07, 2009, 03:17:43 AM
damn, the exchange rate is good right now!
when i bought my roboduino it was about 70/100... :-[
Title: Re: Help for building my first robot
Post by: Judan on August 07, 2009, 03:28:59 AM
not as good as it was when it was around 80 cents that was so nice lol stupid recession bull crap anyway you aussie aswell ? or..

and also how do you connect that blue tooth to somthing i see no connector cords etc and umm ye im gonna go with the bluetooth to control it

im starting to think this is gonna be around 350$ im gonna have to sell some stuff anyone wonna buy a "toshiba tablet touch screen" or anything inside a toshiba tablet laptop lol

(i kinda spilt a liter of milo on it and it fried the mother board(i think)  :-\) luckly the ram cpu and everything attached to the motherboard works so ye anyone wanted laptop stuff gimi a shout lol
Title: Re: Help for building my first robot
Post by: SmAsH on August 07, 2009, 03:37:09 AM
yeah, im an aussie :P
for bluetooth you need a microcontroller with rx and tx ports, check out:
http://www.societyofrobots.com/microcontroller_uart_50_robot.shtml and
http://www.societyofrobots.com/electronics_bluetooth_robot.shtml
Title: Re: Help for building my first robot
Post by: Joker94 on August 07, 2009, 03:47:38 AM
the second link was the exact link i was thinking of when i mentioned bluetooth
Title: Re: Help for building my first robot
Post by: gaurav.p on August 07, 2009, 03:54:52 AM
hey joker94 i too mentioned the link earlier (2nd link) for bluetooth ;D ;D
Title: Re: Help for building my first robot
Post by: Joker94 on August 07, 2009, 04:03:26 AM
sorry gaurav.p. cant believe i missed it. might of been befor i went to school one mornig when i was in a rush. Sorry again
Title: Re: Help for building my first robot
Post by: Judan on August 07, 2009, 04:55:59 AM
no like how do i put connectors or is the bluetooth thing just shown without cords to be seen beter this is the image http://www.sparkfun.com/commerce/images/products/00582-02-L.jpg
Title: Re: Help for building my first robot
Post by: SmAsH on August 07, 2009, 05:04:16 AM
ahh ok, just get some .1" male header pins and solder them onto the board...
you can also solder wires directly but it will be more permanent...
Title: Re: Help for building my first robot
Post by: Judan on August 07, 2009, 08:02:03 PM
and umm now for the claw part
does anyone know how to make a horizontal closing claw (as seen on the 3d pic of the bot) close and open using only one servo  :-\?
Title: Re: Help for building my first robot
Post by: wil.hamilton on August 07, 2009, 09:09:46 PM
http://www.lynxmotion.com/Product.aspx?productID=160&CategoryID=133
gripper using 1 servo
you can look at it for ideas, or just buy one if you're feeling lazy
Title: Re: Help for building my first robot
Post by: Judan on August 07, 2009, 09:39:58 PM
hmm i wont buy it but i can kinda see what they have done for it to open and close ill just copy that hmm what else did i need help with, ummm
oh ye umm when i do end up buying all the stuff im gonna need some help for coding to be able to control the robot from my computer usuing buttons on the keyboard and is there a way to tell how powerfull your motors will need to be to pull certain weights etc   ???