Car Helicopter Prototype

[jpanhalt]

Does your club use 40.685MHz that Google says is used only in Europe for surface models?

I don't see how that is related at all to the OP's question. He has stated that he cannot afford a 2.4 GHz system. Of course, you could send him yours, if that is what is necessary to do his project. I don't think it is.

Does a 72MHz transmitter/receiver detect that a channel is in use then automatically select another channel like happens on 2.4GHz?

We are polite and utilize a frequency management system. We also limit the number of aircraft aloft at the same time (3) to be polite to our neighbors.

Is a 72MHz model "binded" (bound?) to its transmitter like on 2.4GHz so that no other transmitter can interfere?

They are on the same frequency. You seem to confuse frequency shifting with the ability to select an interference-free channel. My receivers are "scanselect," that is, they can be bound on the ground to the transmitter frequency. The transmitter can be set to any frequency needed.

Both the 2.4 GHz and 72 MHz (USA) systems work just fine for flying. There is no reason to trash a perfectly good system just so you can be gigahertz and have a shorter antenna.

Your criticism of the OP's radio system added nothing to help him solve his question. I chose not to respond at the time to avoid going OT. However, in my later response, I did mention mention your comment from the perspective that not everyone would agree the frequency of his radio system and its lack of ability to switch channels was a limitation. The number of control channels he has available may be a limitation, but he has stated he can fly the quadracopter with just the 4 channels. I believe it is possible to map those channels to to fly a helicopter and run a surface vehicle using the stick motions he describes.

John

 

[audioguru]

A guy at the park had a little quadcopter with gyros and GPS. He did some stunts then let it hover perfectly all by itself in the gusty wind. Then he sent it far away up high, pushed a button on his transmitter then it came down and over and landed beside him all by itself.

The wind blows my simple helicopters away.
My helicopters and airplanes are electric. Have you ever seen a gasser (noisy and smoky) model quadcopter?

 

[Sharkbite]

Thank you very much guys, you've helped me a lot. Audioguru, it's my first project, and I'm not even sure if it works. Plus I'm sure I'm the only one that's gonna fly a heli in my area, so there won't be interference.... If I succeed in it, sure I might consider on a 2.4 upgrade, but for now, I think I'll be using my current one.

Jpanhalt, I appreciate your help, and I've made my decision. Micro controllers help my project to be much powerful, with much more uses, but...
I think I'll create my prototype without a Mc first. If all goes well, (that is I can actually fly it without any frying) I'll hook a mC into it.

A small confusion; in the receiver, throttle port goes to the ESC, which connects the main propeller and the power source.

1. Since I'm planning to build a quadrocopter, there will be 4 motors (propellers) . Should all 4 connect to the ESC output or should I use 4 ESC's? (I hope I could use only one)
2. On the other ports of the receiver ( eg. Aileron ), they usually connect servos. If I connect a motor to the aileron port, will the motor spin forward ( when joystick is up) and backward (when joystick is down)?

Is the power enough or extra pore is necessary? I'm planning to use a 2cell Lipo battery, 7.4v.

If i cannot make it work, I'll put in a micro controller then. Hey I'm just a junior in this stuff , can't rush in!

 

[jpanhalt]

Sharkbite,
I am a bit confused. I understood from your earlier posts that you already had the quadrocopter and had flown it. If not, that is the first thing you need to do. It is on the "critical" path. If you put all four motors on the same ESC, how are you going to control and balance it? Copy or buy a design. Many of them will have gyros and MCU's built in. I got the impression you had already flown one without such aids.

If you have no experience with them, then plan on crashing a few times.

As for changing flight modes without an MCU, since one mode is a car with 4 wheels pointed in the same direction, I would put a weight sensor (e.g., a lever switch) on each of a diagonal pair of wheels or axles. The output would be wired in series or go to an AND gate. Therefore both wheels would need to be in contact with the ground to initiate mode change. I would then consider an analog switch to re-map the receiver signals to the appropriate servos or other controllers for ground operation. All of the big semiconductor houses make analog switches. Here's a description from TI: **broken link removed** You could also use relays for the re-mapping, but relays are power hogs.

John

 

[audioguru]

Each motor in a quadcopter is powered from its own ESC. The ESC has very low input power because your receiver is designed for a port to drive a low power servo, not a high power motor. The output of an ESC has very high output power.
The motor on a helicopter is never reversed unless you want it to also fly upside-down.

To fly forward then the front motors are slowed and the rear motors are speeded up. To bank sideways then the motors on one side are slowed and on the other side are speeded up.
To rotate then I think all 4 motors have separate speeds.

 

[Pommie]

Are you guys really encouraging the OP to try to do this?

Maybe you are having fun. Quote AG "To fly forward then the front motors are slowed and the rear motors are speeded up. To bank sideways then the motors on one side are slowed and on the other side are speeded up."

If that's not stating the obvious then I'm (make up your own word).

When is this dumbing down of this site going to stop?

In case anyone hadn't noticed, I don't post much anymore. Whenever I post anything slightly critical I get jumped on.

Well, I'll state my view.
This is a stupid thread, the OP has no idea and no chance of completing his/her project.
The people that have posted above should be ashamed that they didn't point the OP towards a more sensible project.
The moderators should also share some blame for allowing this situation to be tolerated.

I'll go a little bit further and state that it is my belief that the OP is a troll. The questions asked have .... just read them yourselves and make your own mind up.

1. Since I'm planning to build a quadrocopter, there will be 4 motors (propellers) . Should all 4 connect to the ESC output or should I use 4 ESC's? (I hope I could use only one)
2. On the other ports of the receiver ( eg. Aileron ), they usually connect servos. If I connect a motor to the aileron port, will the motor spin forward ( when joystick is up) and backward (when joystick is down)?

How much more ridiculous do the thread titles and content have to get before someone shouts troll??

I'm not sure I want to read the reply to this post but I'll post it anyway.

I used to enjoy this site but the trolls got equal rights. Long live the trolls.

Mike.

 

[large_ghostman]

i didnt see that! i think i just took it all as it seemed and tried to offer help, i fel a bit torn because i try projects that i probably shouldn't and you and others always help me. I feel its now partly my fault there is dumbing down because people like me need the dumb version sometimes but i can see what you say and it makes me sad that i may be part of the problem, but i also think that if a member like you thinks that things are not right then it is a serious matter and shouldnt be taken lightly,i am really sorry pommie if i contribute to making the site dumber, obviously if i dont then thats even better . I think your post is a good one and shouldnt be jumped on but discussed because people like you should be listened too. But its just my view.
I still dont see the Troll in the post but then again i am 13!! and tend to take things at face value, however if you shout TROLL then i for one are ready to listen

 

[audioguru]

Maybe Santa Claus will bring him a quadcopter that is "ready to fly" for Christmas. They come with a 4-channel 2.4GHz transmitter, battery, battery charger and gyros. My local hobby shop has some for less than 50 bucks.

 

[jpanhalt]

Are you guys really encouraging the OP to try to do this?

"Encourage," not really. But telling someone on his first post that he is not competent to do something is not a very effective approach either. There have been several discussions and comments of late regarding the value to members other than the OP when pursuing a topic. Two things seem clear: 1) The OP seems young; and 2) He/she has very little experience in electronics and flying models. I do not think either of those is justification not to respond with our best efforts for those who want to respond. No one is obligated to respond.

The OP did indicate some experience with RC helicopters:

Post#5
I'm using a 4ch transmitter. It is originally for my old helicopter, but I want to use it for this project now. I've bought the ex and tx crystals for this project.

Post#23
A small confusion; in the receiver, throttle port goes to the ESC, which connects the main propeller and the power source.

Maybe the fact that he has a transmitter and receiver now is an indication of what happened. That doesn't bother me in the least. I built my first RC model when I was 9, no help, and no buddy box to help fly it. I crashed it on its 3rd flight. Completely demolished. That only made me want to build another, which I did and continued doing for 60+ years. Maybe the OP is starting out now the same way.

Maybe you are having fun. Quote AG "To fly forward then the front motors are slowed and the rear motors are speeded up. To bank sideways then the motors on one side are slowed and on the other side are speeded up."

If that's not stating the obvious then I'm (make up your own word).

Both AG and I presented that to the OP in different ways. In this case, I think the challenge will be to do it without an MCU and gyro. I do wish the OP would chose a conventional helicopter for his first trial, but that is his choice. As I said in my comment, I don't think the stated goal is even worth trying until he has successfully flown a quadcopter.

If your comment is meant to suggest that I am having fun at the expense of the OP, that is completely wrong. I hope you know me better than that.

When is this dumbing down of this site going to stop?

I can assure you that I am as opposed to pandering as you are. My knowledge about electronics and programming is much closer to novice, and perhaps I see more challenge in some questions than others see.

In case anyone hadn't noticed, I don't post much anymore. Whenever I post anything slightly critical I get jumped on.

I have found your help and that from a few others who also don't seem to post as much today as they may have in the past invaluable. Quality of advice for microcontrollers was a clear distinction for ETO. I am not certain that has really changed. I know you feel it has, but I hope that you and K8LH will continue here. I don't mean that at all in the facetious sense of "we appreciate your contributions." It is more selfish. Ohio is in deep Winter now (2°F this morning), and I am dusting off the MCU project(s) on my shelf.

I'll go a little bit further and state that it is my belief that the OP is a troll. The questions asked have .... just read them yourselves and make your own mind up.

Maybe I am more gullible than others and probably give more weight to the effects of a language barrier on someone. I do think "country" should be a required field.

As for members who are more clearly trolls, I was glad to see some action taken this morning.

Best regards,

John

 

[audioguru]

At the park I asked a professional airline pilot (who also flies model airplanes whenever he can) which real airplanes he flies. He explained that they are all so different that pilots are allowed to fly only one airplane.
On TV yesterday an airplane pilot tried to fly a helicopter for the first time and almost crashed because it is so different.

My model helicopter and model airplanes have electronic stabilization with gyros. But they can do stunts when I want. The wind tries to make them do stunts but the gyros prevent it.

Country field? Many countries today had different names when I learned about them long ago.

 

[large_ghostman]

i also just wanted to point out i completely missed the QUAD copter bit!! i had wrongly assumed we were talking normal copter those weighted bar things that go around with the propeller and make them stable!
ne day i am going to build a quad copter! but not until i am ready to move onto PID control systems etc, i would have thought making a quad copter without a micro almost a non starter for all but the very best.