Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: garriwilson on October 04, 2007, 09:43:54 PM

Title: RC car-transmitter, receiver, 2 servos? 36$?
Post by: garriwilson on October 04, 2007, 09:43:54 PM
Hey please check out this site:
http://www.rcplanet.com/Futaba_2DR_2_Channel_AM_S3003_Servos_p/futj25.htm

and tell me if I got this correct: They're selling a 2 channel transmitter with two servos and a transmitter, steering and throttle rims for 36.95$?

Is that a good price if I'm making an RC car? I think that's all I need right? I can just buy a body kit from somewhere else.
If there are mistakes in my list please fix them.

Thanks for reading!
Title: Re: RC car-transmitter, receiver, 2 servos? 36$?
Post by: Admin on October 05, 2007, 06:51:53 AM
It has all that you need and has an acceptable price but . . .

Its an AM transmitter which means range will be poor and it doesnt come with batteries (the more expensive kits do).

It also only has two channels . . . I dont recommend any less than 3 for a robot . . .
Title: Re: RC car-transmitter, receiver, 2 servos? 36$?
Post by: garriwilson on October 05, 2007, 07:20:22 PM
John, you are like an expert at this stuff, so could you find something for my needs? This is what I need:
1. Transmitter + receiver on the same frequency for a car
2. The car will have 2 (preferably fast) servos for the back wheels for thrust, and I need to figure out a way to steer it (could you help with that too?)
3. A body kit
4. All this stuff has to be from one place because I'm trying to save as much money as possible.

Thanks for the help!
Title: Re: RC car-transmitter, receiver, 2 servos? 36$?
Post by: Admin on October 05, 2007, 07:33:52 PM
Whats your budget?

check these sites:
http://www.societyofrobots.com/robot_parts_list_RC.shtml

This was my very first RC kit (although I got it for the air frequency):
http://www.servocity.com/html/laser_6_fm_ground_systems.html

Its a very good starter kit that comes with everything you need.

But if you have more money, I'd recommend a digital transmitter kit (which I also own) like this:
http://www.servocity.com/html/optic_6_fm_ground_systems.html

Shop around though, as I havent been in the market for these things for awhile now and you might be able to find a better price . . .
Title: Re: RC car-transmitter, receiver, 2 servos? 36$?
Post by: garriwilson on October 05, 2007, 07:49:02 PM
I am very sorry to say that my family is kind of poor. :'( I can't get anything I want and for once my dad bought me EVERYTHING I needed for the 50$ robot and I had fun. We just can't afford anything. My dad is the only one who works and he gets 1300$ a month. I feel bad for him, his whole life he's been working so hard and nothing. It's partly because we came here 3 years ago and we didn't have any relatives here to help us. So now we're stuck and I can't do anything. I'll probably go work at my cafeteria and get 7.50 a day. ;D Well sorry for that if you don't care.  :-[

So, you can see that I can't spend hundreds or even 50 $ for anything like this. I don't know what to do. I hope to become an aerospace engineer and be rich so I can do this stuff as my hobby and give my parents a good life at least when they're old. :-[
Title: Re: RC car-transmitter, receiver, 2 servos? 36$?
Post by: garriwilson on October 05, 2007, 08:03:10 PM
Could I use my HS-311 servos for the motors for my car? I already Modified them. And they're kind of slow right?
Title: Re: RC car-transmitter, receiver, 2 servos? 36$?
Post by: Admin on October 05, 2007, 09:38:16 PM
Hey I understand what you mean. My hometown is in Louisiana, the state with the highest taxes in the country and the lowest wages in the country. I grew up poor too, neither of my parents were able to keep a job. Now they own a comic book store, living off of what is in a child's penny bank :P

Lets not even talk about what happened to family finances after Katrina wiped out everything . . .

So consider this all a long term investment, cause engineers make tons of $$

Perhaps you can cut lawns or do some pool cleaning? Im sure you can make like $20/lawn, so it wont take too long to earn enough.

Quote
Could I use my HS-311 servos for the motors for my car? I already Modified them. And they're kind of slow right?
yea you can use the same HS-311 servos and even the same battery that you had for the $50 robot . . . so all you need is a transmitter and reciever (with the same crystal). You should post your robot! Im curious how others have done it . . .

I browsed around some more for you and found this:
http://www.robotmarketplace.com/marketplace_rc_radioGWT4A.html
Its $57.99, a decent deal.

Quote
Could I use my HS-311 servos for the motors for my car? I already Modified them. And they're kind of slow right?
Yea, servos will work with RC no matter if they were/werent modified.
They are slow, but they are also strong. Just use a bigger diameter wheel and your bot will go faster.
Title: Re: RC car-transmitter, receiver, 2 servos? 36$?
Post by: garriwilson on October 06, 2007, 10:31:54 AM
Hey at this website you posted:
http://www.robotmarketplace.com/marketplace_rc_radioGWT4A.html
Yes, Its $57.99, but no receiver or its crystal included. When you include it the price goes up to nearly 100$.

I'm trying to find a body kit for my RC car (with big wheels) like a truck.
Are these servos: Futaba S3003, faster than hs-311? I'm asking this because it comes with this deal:

http://www.rcplanet.com/Futaba_2DR_2_Channel_AM_S3003_Servos_p/futj25.htm

And in my neighborhood I don't know anyone that needs lawn cutting. It's kind of a non-American kind of neighborhood( I don't mean it's racists) :P  It's like little Armenia-It's packed with Armenians who don't even know how to speak English after 20 years. At my cafeteria, if you work snack and lunch(like 50min. together) you get 7.50 a day  +  free lunch + 1$ dollar to buy a drink. Isn't that nice?
Title: Re: RC car-transmitter, receiver, 2 servos? 36$?
Post by: garriwilson on October 06, 2007, 10:36:55 AM
Is this a good body kit for my purposes?

http://cgi.ebay.com/XMODS-RC-CAR-BODY-KIT-NISSAN-SKYLINE-GTR-V-SPEC-NEW_W0QQitemZ120165644358QQihZ002QQcategoryZ34063QQrdZ1QQssPageNameZWD1VQQcmdZViewItem#ebayphotohosting
Title: Re: RC car-transmitter, receiver, 2 servos? 36$?
Post by: garriwilson on October 06, 2007, 11:10:23 AM
I took apart my old rc cars and I found some pretty big wheels and I found 6 DC motors. Could I use those motors for my car? The wheels diameters are: 2". I had a chrysler car and it has a back pair and a front turning pair. THe turning pair is connected but very flexible, the back part only spins. All of them are 2" in diameter. I think I should connect my DC motors to them? And use the servos for steering? And this is what I want to do: put an HS-311 servo on each back wheel (that's 2 channels) and one Futaba S3003 on the steering wheel for turning(that's three channels. But then the system for 36 dollars won't work cuz it only has 2 channels. So I need a 3 channel radio transmitter, receiver, and 1 servo radio system with an affordable price. Any suggestions where to get them?
Title: Re: RC car-transmitter, receiver, 2 servos? 36$?
Post by: garriwilson on October 06, 2007, 11:18:24 AM
Is this a good package from servo city?
http://www.servocity.com/~servo/html/ranger_3n.html
(1)HS-311 Servo
http://www.servocity.com/~servo/html/hfs-03mm_fm_rx.html
Right now they're out of stock but I can wait and make money while they get more.
The total price is about 80$.

Hey, is there any way to get funds or something? And are there any free sample h-bridges or anything else? Please let me know.
Title: Re: RC car-transmitter, receiver, 2 servos? 36$?
Post by: garriwilson on October 06, 2007, 11:20:51 AM
Since in my car 2 servos will be in the back and they'll do the same thing, can I make them the same channel? Because they'll both act as propulsion in the same direction and I don't want to buy a 3 channel radio system just yet.
Title: Re: RC car-transmitter, receiver, 2 servos? 36$?
Post by: airman00 on October 06, 2007, 05:57:01 PM
Hey,

you can get a lot of parts from free http://www.dutchforce.com/~eforum/index.php?showtopic=13348 (http://www.dutchforce.com/~eforum/index.php?showtopic=13348)

also, I get most of my knowledge from the internet. I search around like crazy on google and on different forums. The internet is your friend.

yes, money is always a problem for everyone. Try finding a robotics club or a robotics team. Right now I'm captain of one and they pay for all the parts.

I forgot where I got the H-bridge from.. Ill look around for it.
Title: Re: RC car-transmitter, receiver, 2 servos? 36$?
Post by: airman00 on October 06, 2007, 06:02:27 PM
Tada , i found it

its the L298 from ST microelectronics http://www.st.com/stonline/products/literature/ds/1773.htm (http://www.st.com/stonline/products/literature/ds/1773.htm)
click on samples to add it to your samples cart

there are others tthat are available in a DIP package instead of those annoying SOIC pins which are close together.


If your email does not get accepted because it is generic( @gmail.com , @aol.com, etc.) get an irishnation.com email, itl'l pass through all their filters!
Title: Re: RC car-transmitter, receiver, 2 servos? 36$?
Post by: garriwilson on October 06, 2007, 06:11:39 PM
Are they going to ask why I want the free sample? What should I say if they do?
Title: Re: RC car-transmitter, receiver, 2 servos? 36$?
Post by: airman00 on October 06, 2007, 06:58:31 PM
Just fill out all the stuff as if you were a company

they called me once but I just didn't pick up the phone. Remember you dont have to answer it, or you could just hang up

Just fill out all the fields on the forms there . Claim that you are making a R/C module kit and your company name is garrisswilson, etc.
Title: Re: RC car-transmitter, receiver, 2 servos? 36$?
Post by: Admin on October 07, 2007, 10:54:20 AM
Quote
Hey at this website you posted:
http://www.robotmarketplace.com/marketplace_rc_radioGWT4A.html
Yes, Its $57.99, but no receiver or its crystal included. When you include it the price goes up to nearly 100$.
hmmmm nevermind, I thought that was included in the price . . .

Quote
Are these servos: Futaba S3003, faster than hs-311?
check the datasheets for both servos (just google for it)

Quote
I took apart my old rc cars and I found some pretty big wheels and I found 6 DC motors. Could I use those motors for my car?
You will need a motor driver, and something to send commands to the motor driver like a motor controller. You can also use an ESC. Just search any of those in the forum search.

Quote
this is what I want to do: put an HS-311 servo on each back wheel (that's 2 channels) and one Futaba S3003 on the steering wheel for turning(that's three channels. But then the system for 36 dollars won't work cuz it only has 2 channels.
You could just use on servo on the back wheel axle, requiring only two servos (the other for steering). A 3rd channel is nice to have though if say you wanted a weapon or something on it later.

Quote
Is this a good package from servo city?
http://www.servocity.com/~servo/html/ranger_3n.html
(1)HS-311 Servo
http://www.servocity.com/~servo/html/hfs-03mm_fm_rx.html
Right now they're out of stock but I can wait and make money while they get more.
The total price is about 80$.
sounds acceptable
Title: Re: RC car-transmitter, receiver, 2 servos? 36$?
Post by: garriwilson on October 07, 2007, 12:32:35 PM
I need help on the steering part of my car. How could I make the front wheels turn? I have 2 sets of them but they use different gear systems to turn with a DC motor. However I want to use a servo for steering to be more accurate. Also, is an H-Bridge used to control DC motors? Can I use this free sample to control? :

http://www.st.com/stonline/products/literature/ds/1773.htm  (thanks airman00)
Title: Re: RC car-transmitter, receiver, 2 servos? 36$?
Post by: Admin on October 07, 2007, 01:07:03 PM
Remember to try and figure stuff out before asking questions - google search, and think! :P

I know its tempting to just have others figure it out for you, but you need to try yourself first . . . your questions can be answered by searching this forum and google . . .
Title: Re: RC car-transmitter, receiver, 2 servos? 36$?
Post by: airman00 on October 07, 2007, 03:23:30 PM
take out the steering motor and just put in a miniature servo to turn it. Connect the servo using the hardware it comes with.

Plan it out before you build it!( use google sketchup and make it to scale)

Like admin said, search around for at least an hour and a half on google and that should answer your questions.


Yes, H bridges control motors. Search google for h bridge for info


also money spent now, will save money spent later. Then you'll just scrap previous robots for parts. IF you plan on reusing the parts make sure you attach them using screws or velcro, NOT GLUE. Its a pain to take off, stick with screws.

,Eric

Title: Re: RC car-transmitter, receiver, 2 servos? 36$?
Post by: garriwilson on October 07, 2007, 06:25:35 PM
I'll make a Google Sketchup of how I plan to make it steer