RC India

RC Models => Self-designed, DIY and College Projects => Topic started by: vArun452 on August 31, 2013, 08:39:01 PM



Title: make a wireless bot using rc plane tx rx
Post by: vArun452 on August 31, 2013, 08:39:01 PM
hello everyone..
can anyone please tell how to use the rc plane tx rx to control the simple 12 volt DC motors,i want to make a pick and place bot,earlier it was a wired bot but now i want to make it wireless using the plane tx rx....i am having a FLYSKY TH9X :help: :help: :help:


Title: Re: make a wireless bot using rc plane tx rx
Post by: buzz_rc on August 31, 2013, 08:44:09 PM
For a bot, you'd be better off using DC servos. People modify rc servos for continuous rotation for this purpose. As far as the question to control motors with your radio goes, you would need a brushed electronic speed controller . Hope this helps.


Title: Re: make a wireless bot using rc plane tx rx
Post by: vArun452 on August 31, 2013, 08:48:01 PM
yes that i know,but do i have to use 4 escs for 4 motors??
and how will i control all the motors with tx


Title: Re: make a wireless bot using rc plane tx rx
Post by: vArun452 on August 31, 2013, 08:49:45 PM
buzz rc can you please suggest me a site from where can i get brushed esc,any indian site??


Title: Re: make a wireless bot using rc plane tx rx
Post by: buzz_rc on August 31, 2013, 08:55:59 PM
I am afraid I don't completely understand your question. You can connect your esc to a channel on your rx to control the speed of your motor. I don't know of any local store that has stock of brushed esc's but other forum members might be able to help you out with that. You may also want to post some more details of your design along with pictures for people to better understand what you want to achieve.


Title: Re: make a wireless bot using rc plane tx rx
Post by: vArun452 on August 31, 2013, 08:59:04 PM
ok....thanks,i will post the pics


Title: Re: make a wireless bot using rc plane tx rx
Post by: nchandra on August 31, 2013, 11:25:22 PM
basically rx control ECS or servo by generating PWM waves. If you want to use DC motors you would be needing H-bridge circuit along with circuit to convert pwm to ON/OFF logic for H-bridge. This is quite easy if you can do m/c programming.and  this would be efficient implementation.

Or you can hack the servo by destroying its potentiometer to rotate 360.


Title: Re: make a wireless bot using rc plane tx rx
Post by: mohammadadam on September 01, 2013, 12:46:55 AM
    rotating the servo and using it for larger time may lead to overheating, the best way is to use 4 motors and two esc will do for manuering. for lift and placing use servos.

 hope it helped  :)


Title: Re: make a wireless bot using rc plane tx rx
Post by: vArun452 on September 01, 2013, 12:49:17 PM
this is the bot which i want to convert into wireless bot using my flysky 9x


Title: Re: make a wireless bot using rc plane tx rx
Post by: AnjanBabu on September 01, 2013, 01:33:21 PM
I'm just going to add a few bits to the already-mentioned replies,

1) Like mohammadadam has suggested, Use 2 ESCs, one for right side motors and another for the left side; just make sure the ESC can handle the added current draw of both motors.
Even though it's a two channel control, you may find the stick controls to be a bit weird. For that, you can use an Arduino or whatever microcontroller platform you're familiar with, to assign appropriate control actions to the signals coming from the receiver-- example: stick up/down= forward/reverse and stick right/left=steering left/right.

2) As suggested by nchandra , you can use a H-bridge with a microcontroller as an alternative to ESC (requires PWM modulation between H-bridge and Rx). You can DIY a dual H-bridge circuit with L298N IC or purchase a dual motor driver.

L298N IC datasheet-- http://www.alldatasheet.com/datasheet-pdf/pdf/22440/STMICROELECTRONICS/L298N.html

Good luck, my friend. :thumbsup:


Title: Re: make a wireless bot using rc plane tx rx
Post by: vArun452 on September 01, 2013, 02:35:54 PM
thanks anjanbabu and others for helping... :bow: :bow: :bow:


Title: Re: make a wireless bot using rc plane tx rx
Post by: Shyam Hembram on September 01, 2013, 05:38:45 PM
this will help
www.thehobbyshop.in/index.php?main_page=index&cPath=68_69


Title: Re: make a wireless bot using rc plane tx rx
Post by: vArun452 on September 01, 2013, 09:43:04 PM
Thank you Shyam Hembram...


Title: Re: make a wireless bot using rc plane tx rx
Post by: vArun452 on September 01, 2013, 10:15:45 PM
ok.....now i have the 2 brushed escs,4 12Volt DC motors,flysky 9x radio,lipo.....
so now do i have to simply plugin the escs on the chl 1 and chl2 to move the bot in all four directions??? or any third component is needed?


Title: Re: make a wireless bot using rc plane tx rx
Post by: Shyam Hembram on September 01, 2013, 11:20:53 PM
can u move ur bot in reverse direction with this bruhed esc


Title: Re: make a wireless bot using rc plane tx rx
Post by: v2 eagle on September 02, 2013, 09:57:35 AM
Hi Arun,
If you have a good programming knowledge in any Embedded platform like 8051, ARM, PIC, AVR, Arduino, or even Lego, you can do that without ESC, brushless motor,. but you should have a programmer for that any embedded device i mentioned above.
its simple like you read the signal from RX, get the info, control the Geared motors using L293d,. Easy and clean failproof way. Cheaper too. and lot of people have made it too.
And yes, you dont need a LIpo, 4AA batteries are enough, you can turn that in both directions which is not possible with ESC.

AK.


Title: Re: make a wireless bot using rc plane tx rx
Post by: lastRites on September 25, 2013, 12:49:55 PM
Those motors will burn up a L293D. Since the OP already has two escs he only needs to program the radio mixes(assuming the the left and right escs are on ch X and ch Y) such that:
The throttle stick will directly control both x and y
The aileron/rudder channel will proportionately increase one channel and decrease the other to facilitate turns.
I have heard people using v-tail mixes for this but I haven't tried it myself.


Title: Re: make a wireless bot using rc plane tx rx
Post by: v2 eagle on September 25, 2013, 12:58:21 PM
Lastrites,

from the picture, he seems to be using a brushed geared motor normally used for robotics project. L293d works well with them. And generally Brushless motor ESC combo will not go good with Robotics due to its high speed and low torque.

Ashok.


Title: Re: make a wireless bot using rc plane tx rx
Post by: lastRites on September 25, 2013, 01:15:31 PM
I think you are mistaken. Those motors come from a variety of dealers and draw from 300mA to over an Amp.(I speak from experience) Now he is using two of these in parallel for each side, coming to a total of four motors on the bot. So the maximum current draw may go well over four amps :P So a L293D(or the L293DNE) is NOT suitable for this robot. Two L298s , one for each side, may do the trick though.. And nobody mentioned Brushless motors :P


Title: Re: make a wireless bot using rc plane tx rx
Post by: lastRites on September 25, 2013, 01:25:51 PM
With a bit of tinkering you might get brushless motors to work with robotics.
Check out my car which uses a 2826 motor with a bad bearing ;D

http://www.youtube.com/watch?v=5K1VAu8yhi8


Title: Re: make a wireless bot using rc plane tx rx
Post by: v2 eagle on September 25, 2013, 01:29:00 PM
Nice work man {:)} {:)} {:)}, a little faster though ;D


Title: Re: make a wireless bot using rc plane tx rx
Post by: lastRites on September 25, 2013, 01:38:30 PM
I got it working with a plastic gearbox(gears from an old printer) and acheived close to 35kph at about half throttle. But the gearbox went bust :P
back to the thread topic... I forgot to mention that when using mixes from the radio, the robot will not be able to go backwards unless the brushed escs are reversible..


Title: Re: make a wireless bot using rc plane tx rx
Post by: v2 eagle on September 25, 2013, 01:59:31 PM
You are right.
But can we do the precise movement for pick and place by a brushless motor. and cost involved for ESC, LIPO,Brushed motor  is a burden.
a l293d, 4 motors, and a PIC development board is a easier way to the job. 433Mhz  TX& RX are available for 1000 rs instead of a costly RC TX and they work for hours on a single 9v battery for hours. with a bit of programming we can have 32 channels !!!   


Title: Re: make a wireless bot using rc plane tx rx
Post by: ghoshatanu56 on October 15, 2013, 12:19:52 AM
U can use arduino board and its pulsein function to read rx signals ( ie 1 ms,1.5 ms,2 ms)pwm signal for different stick positions.And then u can output different output singnal on arduino pins which u can connect to an MOSFET H -bridge(yes u can make ur own H- bridge instead of using an ic.it can help u drive even heavy motors).this should do the job although there will be some glitch at certain interval of time.


Title: Re: make a wireless bot using rc plane tx rx
Post by: sudhakar_yg on October 25, 2013, 03:02:31 PM
Hi Varun,
Try this link for more info.
http://www.instructables.com/id/How-to-Control-any-RC-car-with-an-airplane-transm/?ALLSTEPS

I have made a bigger bot using this interface method.
Here is the video of my bot.
http://youtu.be/9KW7nnuMiMw


Title: Re: make a wireless bot using rc plane tx rx
Post by: akashflyer on October 29, 2013, 11:25:05 PM
You need not to turn your servos to full rotation neither they will work that perfectly..do one thing just use normal DC motors and you can use MOTOR DRIVER ICs such as L293D to Drive and Control Them.COnnections I can tell you... :) :)L293D works perfect till 24V You will have to use two of them for controlling 4 But if you are connecting two motors on each side together then only one can work..


Title: Re: make a wireless bot using rc plane tx rx
Post by: akashflyer on October 29, 2013, 11:30:07 PM
But Definately you will have to use ESC's if you want to control their speed...otherwise i think you need not to use any speed controllers in such bots...you must be using 150-250 RPM Motors..on applying load their full speed is also so less that they can be easily controlled..this was just my suggestion rest is on you... :) :)


Title: Re: make a wireless bot using rc plane tx rx
Post by: lastRites on October 30, 2013, 07:28:53 AM
Speed control can be easily achieved through L293D.