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Where is our quadcopter?


#1

Every time I see this I feel like stopping everything I am doing and start working on a quadcopter.

Make sure you see the 8-shape formation at the end.


#2

That is frickin’ unbelievable! The big square formation had 20 (?) copters in it! These guys have got to be heavily funded by some secret government organization, or maybe they got access to alien technology ;D

Let’s just hope they open source it.


#3

Weekend project?


#4

Anyone else watch this and think…Skynet?


#5

LOL, i read that and it caused me to laugh my coffee out my nose, thanks :wink:


#6

FWIW, I came across this site the other day for modifying speed controllers to give them more response.
Many of them are designed to ramp up to the desired RPM. Which of course a quad copter need as quick response.

http://wiki.openpilot.org/display/Doc/RapidESC+Database

I bought a few of these speed controllers from here which you can change the firmware to get the faster response.

http://www.quadroufo.com/product_info.php?products_id=37&osCsid=akvul3s872o593rk9p49k0c5v2


#7

Incredible.

I built a test stand for my copter project last weekend so I can move it back into my office and hopefully make more progress. The pain point for me at this stage is getting the computer and the copter together in a space that allows for debugging. This problem is compounded by the fact that my remote also needs to be attached to a computer. So, I’ve built a test stand that I can mount the copter to for testing balancing code w/o having it actually fly around the room.

I really like those tiny copters. This reminds me of something else I’ve been thinking about. What would be awesome is a Hydra with minimal PCB size and no sockets attached initially. It would have some way to map the pins to just sockets needed. So, if I only need a couple X sockets and a P socket then that’s all I would solder on. Considering the cost of the IDC sockets, this should help quite a bit towards making a cheaper Gadgeteer mainboard and for projects such as copters it will also help eliminate unneeded weight. Unfortunately, there’s really not a FEZ for sale anymore that’s feasible for such small projects :frowning:


#8

Wanted to add to the pot of items one can use.

If you want a very good 2.4 radio/receiver, i got this one in for mine and it has a good feel and has a ton of options in it.
http://www.hobbypartz.com/79p-th9x-r9b-9channel-radio.html?gclid=CJ6jj-PC9q0CFWQ0Qgodxnacsw

Low cost but excellent gyros, Used them on my coaxial heli conversion.
http://www.xheli.com/60p-dy-1017.html

I have been modifying my 48 INCH COLOSSUS Helicopter. It comes with a very cheap radio, and electronics. I replaced the 2 brushed motors with 2, 4500kv brushless motors. installed 3 speed controllers ,2 gyros and above radio. Fly’s great now :wink:


#9

This too would make a some sort of cool flying thing, Eliminate torq roll with this.
With 3.54lbs of thrust makes it worth wild.

http://www.hobbypartz.com/88e-mc451-cr28m-counter-blade3-1050kv.html

Yet i like this one better. less thrust but i like the looks better.
http://www.hobbypartz.com/88e-mc351-cr23m-counter-blade3-1550kv.html


#10

Cool props. Good thing I didn’t see those when I was buying :slight_smile:

I spent a good part of the weekend working on the balancing code for my copter. I still need to do a lot to tighten the loop. It’s responding too slowly and doing a lot of swaying back & forth. I’m communicating with the IMU through a SerialPort connection and processing that is a good part of the pain. A lot of GC going on… The IMU also has an I2C connector. So, I may try that next and see if I can poll it rather than deal with all the serial data. With any luck I hope to be able to post a video of it balancing in one dimension by the end of the week.


#11

I was just to lazy to code mine :wink:

I wound up using 2 gyros, one for the x and the other for the y axis.
Each gyro’s output is then connected to one input of a v-tail mixer. the other input is connected to the throttle. Then the same for the other axis, balanced beautifully all by itself :wink:


#12

Interesting. I’m certainly an R/C noob. I’ve never heard of such or I might have gone that route also. Is all of this dependent on you also using a standard R/C receiver system or could it work with a custom receiver? I’d love to see a pic of your configuration.

Does the V-tail mixer always balance? How do you move forward when one motor needs to go faster than the other?


#13

I am using the tx/rx posted above. That TX has many awesome features that allow you do what one needs to pull this off. Though i would have to say that any higher end transmitter with LCD and configurable options would allow one to do the same. Like spectrum or Futaba, but your going to pay way more for those radios.

I wish this question had come up 3 days ago, because i had this whole thing set up on the bench and you have taken a video of it, But I have taken most of this stuff and put it into the heli as shown above.

Basically, the v-tail mixer takes 2 inputs, mixes & combines them into 2 outputs for the 2 servos.
It is used for radio systems that dont support mixing for planes with only elevons like this one.

http://secure.hobbyzone.com/PKZ4200.html?ucroi_kw=parkzone%20f27c%20stryker&ucroi_adid=83601&ucroi_google_type=GoogleAdWordsSearch&gclid=CPr9nu_oia4CFQ9-hwodFRFA6g

There are only 2 surfaces to fly with on this plane, the up, down, left & right are all mixed for those 2 surfaces.

OK, so what you do instead of taking the pitch and roll as your inputs, you take the throttle (for your up and down) and the pitch as your inputs for one axis to the v-tail adapter. then you take the outputs of the v-tail adapter and run them to each of your your ESC’s. When you move the throttle up it will increase the RPM to both motors together, but when you move the pitch stick it will increase the RPM to one motor, and decrease the RPM to the other motor. The best way to see this is to take 2 servos and connect them to the v-tail adapter, you will see what i mean.

Now, here is where the gyro comes into play. The Gyro has an input and output. Its original intent was to be used to control the tail blade pitch on a heli. to keep that boom locked into position regardless of wind conditions or head rotor RPM.

Basically, think of the gyro as whatever signal comes in goes out. So say i have my tail stick at 25%, I am doing a slow spin in air. the gyro will take that 25% signal and pass it along to the tail servo.
All is well. BUT, now i slam my throttle stick to 100%, that initial amount of torque would typically send the heli into a uncontrollable spin. But with the gyro installed, it detects this instant torque movement and will take my tail stick 25% and either add to it or subtract from it to cause the tail fin pitch to keep the heil at that position. This is the beauty of the gyro.

So what did is take that concept from using a servo, and put it to using an ESC. and combining it with the V-Tail adapter gives you the gyro stability, and the v-tail gives you mixing and the ability to control 2 motors with one device.

Hope that all made sense.

P.S. I ordered more Gyros, as i want to make another quad-copter again, but this time around i want to use ducted fans instead of propped motors. Is just safer and i love ducted fans :wink:
When i get the stuff in, i will post a video of the receiver, v-tail and 2 servos to show how it all works.


#14

Wow. Thanks for the education. I’m starting to understand. I think this will only work in a “+” configuration quad though. Ultimately, one of my goals is to be able to switch between a “+” or an “x”. I don’t see how the mixer could work in an X configuration w/o adding some relays to dynamically tell the motor which mixer to use. It’s definitely nice to know that these options are out there. Let me think how I can maybe integrate them into my design. The ones at HK are very cheap also.


#15

welcome, x will take some thought. I have posted a short video showing this concept on youtube if interested.


#16

Thanks, jdal. That’s certainly a beast of a copter you have there. Does it fly you to work in the mornings? :wink:


#17

You guys are making me soooo jealous! My quad’s been shelved since last year. Just not getting time to work on it.

JDAL, I like how you solved the problem with “analog” techniques. I tended to get fixated on PID loops and digital commands - but maybe there are other approaches that can work here? NETMF will never be able to sustain a PID loop, but it will happily coordinate “offsets” in an analog system that balances itself. Interesting.


#18

@ ianlee74

i wanted to find one of the largest coaxial design helis i could find. They are much more stable than the smaller ones. The biggest problem is that it has far to much power. I put 4500kv motors in there only because that is what i had on hand. Had no idea it would be this powerful. 50% stick on this puts it about 100’ up. To really see how big it is, you can watch this link.

I love watching his videos, I don’t buy anything unless he has ran it through the ringer. If it can make it past him then its a good heli :wink:

@ realiser,
I am not sure what you mean by “how you solved the problem with “analog” techniques.”


#19

That guy’s intense. Those props really seem tiny for that size copter :slight_smile:


#20

He sure is :wink: Thats why i said if it can survive him it can survive just about anybody.

as far as the blades go, yes they do look small but ya have to remember that there are 2 sets, so its twice the length as one.