Wireless remote controlled 4 wheeler

Started by cvjoy, December 16, 2010, 07:23:01 PM

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cvjoy

i am a fan of microcars but dunno excatly how to build them or niether do i have enough finances.

what i have is a 4wheeled small car(those like robots controlled by wire).
you those level 1  robotics stuff all wired (H-bridge.)

so what i want to do is to control it "wirelessly" using anyway that is cheap.
i am complete noob in RC so am here to start it.
hope i get some usefull tips
i have already have a level one 2 wheeled robot with a real basic remote wired to 2  :Rs:50  motors. :P
i can start it afresh or can use that one.
anytips for real basic people ?   ??? ;D


*i am from mumbai so references related to places here would be ideal*

anwar

Buy a cheap toy car, and try to reuse its RC electronics ? :headscratch:
Hangar : Please see my introduction.
RC India forum and me : About this forum.

cvjoy

i know those cars exist but the their tx/rx seems to real  :banghead:

cvjoy

i Bought a car as said it's name is
X-Gallop

exporter : FORCE LINK (Hong kong)
importer : Holy Enterprises

3.6V Ni-Cd in Car
1x9v for Tx

finally made in china so not sure of quality  :'(
4 channels -27,35,40,49  Mhz
front and rear suspension
semi-proportional right and left steering
sealed gearbox which think has started leaking by now :help:

Got a charger for Ni-Cd battery and there is a antenna jutting out  :giggle:
pics will posted next time.  ;D

cvjoy

by driving that car the RC looked  :banghead:
so mostly using those components is slightly out of question now
can i build it from scratch say 4 motors 4 wheels then ..connect RC components one by one

cvjoy


traxxrc1

Although i have never done something like this but i would suggest you to first build a flate plate chasis made of metal or carbon fibre. Them try mounting axles on the chasis, dont think for differentials, try to copy the way a small toy car of 100-200 rupees is built. I will think more and update you
cheers...!
Arpit
I'll be back.

cvjoy

thanks for a reply
i thought that thread had gone dry

but still hav started work so leaving differentials alone i am thinking of a 4 motor combination
so each motor can be controlled separately.
is that any good?

traxxrc1

Welcome, but before your question i would like to ask that is your model going to have any speed controller?
I'll be back.

cvjoy

Never thought of a speed controller
all i wanted to do is use motors and connect it to a receiver and hold a transmitter in my hand be able to use that car.

rajathv8

Yo can use a 27 mhz radio tx and rx for this - scavenge it from a toy car. Should be pretty simple but the problem is this - its of no use ,both performance and knowledge wise, to break a toy car and make it again. Connecting motors is just a matter of soldering or using cello-tape.

cvjoy

i have a tx
rx will hav to cut through my car
then how do i control a bunch of motors and wires  through those?
does anyone have a schematic of connections?

rajathv8

When you open up the car to remove the rx just make a note of the wire connections. The car will already have two motors - one for fwd/rev and one for turning. If you want to use 4 motors, you will have to connect them in parallel or series ie two sets of motors, each with parallel or series connection. This will reduce either the voltage or current per motor and either way you will end up with 4 slow motors.

traxxrc1

I'll be back.

cvjoy

@ rajath
i am not trying to rebuild that toy car but make my own which is more powerful .

the suggested reply seems to be true but albeit slow will it have the required torque?(i am expecting a no but yes would be better)

i am thinking of not using metal and carbonfibre atleast in india for me is out of question
am so thinking of acrylic/ HDPE sheet for chasis will that do to reduce weight and increase speed.

also i know this could be overboard can i stick a speed controller inside without causing much harm to it's movement.

i have that ni-cd battery but i do also a lead acid 12v sealed small battery will that do?

rajathv8

Hey im no expert, what i said were just a reflection of my thoughts. I may be wrong also :)

Torque again depends on the power supplied to the motor - if power is low due to power sharring between motors torque will be low. Having enough torque or not is a mater of mathematics or trial and error :D

Use coro - should not add  lot of weight. Perhaps you can fabricate a frame with carbonrods/wood/diwali rocket sticks etc and place the coro structure on the frame. Experiment the electronics on such a base then look for a "better and final" alternative for the body.

Well in theory if you can convert the output from the rx of 27mhz rx to a form to channel propotional amount of power from battery to motor then ESC is possible but there is a catch - the rx is ON OFF type so the ESC output will be maximum power or no power. Such a setup is equivalent to not using an ESC except in the sense that it delivers more power to the motor.
The ESC will behave as a switch only.

Lead acid battery will be heavy right?

chokxxi90210

Hey Cvjoy dude, bro you need to get a proper ESC for any vehicle, its basic principle of any vehicle that the speed increases from low to high....if you just connect 4 motors on 4 wheels and operate those just by a ON/OFF setup, how on earth you'll make a speedy car ?

get a cheap RC car, strip it, look at the mechanism, and then apply your ideas to enhance that mechanism with better electronics. you can buy cheap motors from chinese companies like Hobbyking, ESC etc. you can get second-hand from the sales section of this blog. Recently someone was also selling a tx / rx for cars....

Cheap RC Cars available in market dont have a ESC, its just a remote controlled on/off switch.

cvjoy

I have posted my specs as above dunno if they are really correct so temme what all can i take from it
i can purchase motors separately  (advice me on a standard motor setup  [rpm and speed])

cvjoy

i don't expect my car to be as below

http://www.youtube.com/watch?v=SXt6DQd-6Tc&feature=related
:giggle: :giggle: :giggle:

you might catch my legs in that video though  :giggle: