randee

Sorry for the bad subject line!

Like the forums, lurked before but never posted.
I have searched for this info and couldn't find it, I am sure I am just not searching for the right thing.

I am interested in making a radio controlled lawn mower, but want to learn how radio controlled things work. How can I control just a normal motor. For example, I was thinking I might use a windshield wiper motor to power the wheels. I have no idea weather it would work or how it would be connected. I can physically put it together, and I can power the motor, but when it comes to the radio controlled bits, I am lost. I know I am a newbie on this, and I want to know resources on how this can be done. Places like howstuffworks dot com and other sites tell me the details, but nothing on actually doing it yourself.

Books?
Links?

any info would be appreciated!

Thanks,
Randy

sheograth

Ideally you should start with a self-propelled powered lawnmower. That way all you have to do is actuate the throttle and steering using servos. That's an oversimplification obviously but that's the direction I'd take. Basically the radio control system simply allows for you to control the servos - what you do with those servos is up to you. You can use one or more servos to actuate any linkages or controls the engine and carb may have, and use one or 2 powerful servos to actuate the front wheels.

randee

Thanks for the info!

So does the servo control a potentiometer of sorts to control speed and forward/reverse? I see how the receiver can control a servo, but how does a servo control an electric motor? Or am I missing something?

I like your idea of using a self-propelled mower! But I think it would be more fun for me to build the drive from scratch. Plus I am thinking about making a catapiller tread beast for mowing my friends steep hill safely.

Thanks again,
randy

sheograth

In modern electric vehicles, the receiver controls a solid state variable power supply called the electronic speed controller, which drives the motor. In older vehicles, the receiver drives a servo which controls a fat variable resistor grid, which controls the motor. Those are called mechanical speed controllers and have no advantage what so ever now that solid state controllers are available.

In gas/glow powered vehicles, the servo actuates the throttle body on the carburetor, which is what you would be doing in a gas powered mower.

So to sum it up - modern electric vehicles only use servos to control steering, since it's a purely physical thing. The motor is driven by a solid state circuit, which takes the place of a throttle servo. The receiver doesn't know the difference basically.

Barber420

My Feedback: (1)

The receiver plugs into an esc(electronic speed control) which in turn sends controlled power to the electric motor in an R/C car application. You could use one receiver to receive the signal, one servo to control throttle, another to control your drive, and then one STRONG servo to control your steering. for this you would need at least a 3 channel radio. It would be a fun project, but it will probably a fairly complex task and tuning everything to work properly could be tough. Good Luck!!!!

rclugnut10

My Feedback: (1)

why the 3 channel held just need, 1 trottle if that, and 2 sterring servo's i'ld get 1/4 scale, mg's, with around 200 ozin at least and then get this http://www3.towerhobbies.com/cgi-bin...&I=LXL307&P=ML and you'll be set, once you get the hubs one the steering set and you'll also need a reciver pack any 5 cell (6v) with at lest 1200 mha should have you set a 3rd channel will give you another servo to control, each channel controls one servo movement so if you wire 2 servo to the same channel they do the same things

the lug

randee

Thanks sheograth,

That is a very good explanation, and it gives me some vocabulary I was looking for. Electronic Speed Controller. I need to see if I can find one that can handle strong loads and 12V.

randee

Thanks for the info, Barber420,

I feel I have a difficult road ahead of me!

I was even thinking about caterpillar tracks! I suppose that will even be more difficult... I want this machine to act as a snowblower in the winter as well.

This of course is a dream, but sometimes we can turn dreams into a reality...

Thanks for your input!

randee

Thanks rclugnut10,

I now know you can hook up to servos to the same receiver port? excuse my bad lingo...

I have no idea where I can find some of the parts I got in my head, they may not exist. Like the tracks... 4" wide rubber tank tracks... might not exist in this world... yet! jk

I will do some sketches and reply back so you guys can see what the heck I am trying to build...

Thanks for all the info and quick replies!

hands without shadows

You need more than a 1200 mah receiver pack to power 1/4 scale servos. Something in the 3000 mah range with sub C cells at least. A 12 volt battery with a voltage regulator would be my choice.

Check out battlebot forums too.

randee

thanks, hands without shadows, is that like so fast hands? Reminds me of channel 5 kung fu... Beware, his kick is without shadow...

I am planning on doing it with a 12 volt battery if possible,

I would like to have a 5hp engine to drive the lawn blade in summer and a snow blower in winter. Ideally I would like the engine to also generate power charging a car 12volt batter, that in tern would be the power for the radio controlled equipment and electric drive motors. Good to know a 12v battery is possible.

Does anyone on here know how to steer a tank via R/C? I assume its just right and left forward and reverse, but I am probably just wishful thinking.

Randy

hands without shadows

Tank steering is simply left/right forward/reverse.

You want the drive system to be electric correct? The only things you want powered by the gas motor are the blades, blower, and some kind of generator system? If so I would be checking the local ads for electric wheelchairs. They have adequate power to move the mower around and up hills, have tank steering, move at a reasonable speed, and you wont have to worry about gears and belts, etc.

I dont know too much about the generator thing. The only thing close in RC terms is a system used on large scale planes and I don't think it will work for 12v batteries. A car alternator might be easiest?

The actual radio system that you will use to control the mower needs at least 3 channels. A channel can control one thing, like a speed controller or a servo. You need one channel for right side drive, one channel for left side drive, and one emergency engine cut-off. Additional things like lower/raise deck, deck clutch, or chute rotation all need their own channel. The radio you use must operate on 27 Mhz, 75 Mhz, or 2.4 Ghz. These are ground frequencies. I would stay away from 27 Mhz because basic Wal-Mart toys use this frequency, and I would also stay away from AM because it is prone to interference. This might all sounds like gibberish but you will understand once you start deciding which radio to use.

hands without shadows cause my hands move so fast my shadow can't keep up

randee

ya! thats what I was thinking... using car parts, we got salvage yards just wasting away... I like to reuse as much as possible, not because i care about the environment, just cause its cheap! jk...

the electric wheelchairs are commonly used in these type of setups, but i can't seem to find a cheap one around here.. plus they are 24volt, hard to generate a recharge voltage.

only somewhat gibberish... thanks for the info...

i would like to buy a controller with many channels so I can add on different things like the stuff you mentioned! All cool stuff, this can be quite a project. do you have a recommendation for a controller/transmitter? something inexpensive perhaps off ebay?

Thanks, randy

EloyM

My Feedback: (194)

There is a frequency concern, which is under federal law through the FCC (Federal Communications Commission). You can not use 72 or 75 MHz equipment, licensed only for "flying models: and "non-flying models" ( read "models", not "things") only. You can use 27 and 40 Mhz which are licensed for "radio controlled items" and for the short distances that you will probably be working would be virtually interference free. I am not sure what the law reads about 2.4 GHz (Giga-Hertz), it is worth some research,

In addition to the legal issues, there is a moral one in that if using one of the model only frequencies, you could cause interference to someone's very expensive airplane/car/boat and cause damage to it or other property or people. Please be careful.

randee

Well, I wouldn't want to cause someone's model damage. How would this be any different than me using my radio controlled car?

It probably will be a model, cause it may be smaller than a normal mower/snowblower.

Guess if I see someone flying their model I can wait for them to finish or make sure they are not on the same wavelength.

randee

You know any good idea i have ever had, someone has always done it before me.

http://evatech.net/GOAT2007T.html

But it doesn't have a snowblower, or cameras, like mine will.

Nice guys, I talked to them about just getting the tracks and wheels for mine, they said it would cost about $2,700. The whole unit costs $12,000!
If I was rich I would just buy that...

Anyone know where to find tracks like that? Something has to use a similar set up. Maybe on a snowblower, or a small snowmobile...

rickster3057

Hi Randee, man thats a crazy idea, but very cool never the less.
If your gonna do it on the cheap they are selling a radio controlled tank on ebay for $59, its 3 FOOT LONG
This will give you ,your tracks, radio 3-4 channels i think, all the motors and save the headache of trying to get or make your own tracks and it will also give you a hull to attach your mower /blower to.
They also sell small wireless cameras on ebay, i have three and they can be used day and night and have audio, yes i know you can get wireless camera vison glasses but they are expensive
Also you might want to try a marine speed controller I use one of these on my tracked/truck hybrid with a 12v battery on a normal 27mhz radio tranmitter and reciever, bought on ebay for $20.00
Doing it this way you get to experiment with all your ideas then if you want to build an aluminum hull run all metal gears and tracks also selling on ebay for heng long tanks.
2.4ghz radio is a great idea for non interference but expensive and there is enough seperation between 27mhz ground channels not to interfere with RC cars and boats.
Hope this helps ya.
Rickster3057.

fly boy2

I bet you can build one way less then what they are asking for it. If you already have the transmitter that saves some money right there. Just buy a cheap push mower and you have a deck, motor and some wheels that can be use as drive wheels and guide wheels. You talking about this makes my want to make one. I've been wanting to make one but I didnt think about the tracks. I bet it will be a fun project. Keep us posted I will like to know what it looks like.

Rodney

Check out some of the many Robotics forums for this kind of info, there are quite a few of them.

hands without shadows

Tracks: http://www.robotmarketplace.com/prod...le_treads.html

They are expensive though.

randee

Thats an awesome item, outta my price range, but still thanks for showing me.

randy