Drone build

[jussi]

Someone gave me a little toy quad a while back as a gift and I had a blast and decided to try build one of my own. It's a 650mm class quadcopter and will spin 14" propellers and will eventually hold a gimbal mounted go-pro. I dabbled a little into RC cars many years ago but not much. Things have progressed quite a bit since then. Even the batteries are quite different. Before I started I had never heard of Lipo batteries before. And charging them correctly takes some understanding as well. I'm not that great at soldering but I think I did ok. Right now it's a rats nest of wires but everything seems to be working as expected. Even the retractable landing gear. When I'm done I'll be using lots of zip ties to make it look alot cleaner. Hopefully. First 2 pics are the top with the top frame off, 3rd pic is components underneath, and the last a vid of the motor and landing gear test. Sorry for all the noise in the vid, didn't realize the little fan I had on would translate to so much noise.









http://vid232.photobucket.com/albums...psfbfl9q7e.mp4

[atgcpaul]

That's cool. I was surprised to see (probably shouldn't have been) that the chassis was the cheapest part of this build.

What's the expected flight time on a full charge?

[jussi]

What's the expected flight time on a full charge?

I currently have a 6S 4500maH battery and according to the program I used it will be 10-15 mins (depending on what type of flying I do). But I plan to eventually add a 2nd identical battery which would push it to 17-23 mins. I debating on getting larger capacity batteries but that would only increase my flight time to 20-26 mins and I'm not sure the extra 3 mins is worth it.

That's cool. I was surprised to see (probably shouldn't have been) that the chassis was the cheapest part of this build.

Yah it's definitely not a cheap hobby. Things add up real quick. But you could of course start with a much smaller, much less expensive set up. It would have been cheaper if I bought a pre-made one but I really liked being able to use the components I wanted. Plus the whole building it yourself aspect of it is really fun. Probably why woodworking appeals to me. It seems the hobby is really picking up steam and alot more companies are popping up and coming up with really cool things. I think the utilization of GPS was the big turning point. It makes it so much easier to fly and control and opens up tons of possibilities. They have things like "follow me" mode where the copter will follow you (or rather the controller / cell phone) at a set distance or "way points" which allow you do download a google earth map and program where you want the copter automatically. I think the next big thing will be perfecting sonar / object avoidance. This would be particularly useful indoors where GPS is not available, besides of course avoiding crashing into things.

[capncarl]

Question about the remote. Does it vary the power to each motor or does it tilt something ? Is the landing gear servo powered? What other controls does the remote have?

[atgcpaul]

I currently have a 6S 4500maH battery and according to the program I used it will be 10-15 mins (depending on what type of flying I do). But I plan to eventually add a 2nd identical battery which would push it to 17-23 mins. I debating on getting larger capacity batteries but that would only increase my flight time to 20-26 mins and I'm not sure the extra 3 mins is worth it.

Is it relatively simple to swap out batteries? Could you have a charged spare and when the in-use one is drained, you land it and swap? Is there a "fuel gauge" on the remote so your drone doesn't drop out of the sky?

[jussi]

Question about the remote. Does it vary the power to each motor or does it tilt something ?

The copter moves by varying the power of each motor but that's controlled by the flight controller, not the remote. The flight controller is the brain of the craft and interprets the commands of the remote and translates that to the ESCs which power the motor. The flight controller also handles the stabilization, GPS, return to home, follow me and many other operations (depending on the model you get). On mine it's that yellow box in the middle of the copter with the wires coming in and out of it.

Is the landing gear servo powered? What other controls does the remote have?

I'm using a Spektrum DX8 which has 8 channels / switches. All or which are programmable. Below is a pic of the remote on the manual and the switch select menu on the remote. I'm using a Spektrum AR8000 receiver which also has 8 channels. But 4 of those are reserved for the copters flight (rudder, aileron, elevator, thrust) so that only leaves 4 switches left one of which is for the landing gear. And yes it's servo powered. Right now it's functioning but one leg starts to retract a second or so earlier than the other. It doesn't really affect the functionality so I haven't really tried messing with it for now but may in the future.

[jussi]

Is it relatively simple to swap out batteries?

Yes I soldered on bullet connectors to the upper frame which (for my model at least) serves as a distribution board. So it's easy to plug and unplug batteries. One thing that freaked me out was the somewhat large spark when I first plugged in the battery to test it out. I thought I had fried something for sure. But I've read it's quite normal especially on the larger voltage batteries. I believe it has something to do with the capacitors of the ESCs charging. I've lessened the spark by plugging in one terminal at a time but am now looking at other alternatives like anti-spark connectors.

Could you have a charged spare and when the in-use one is drained, you land it and swap?

Yes, but to a limit. You eventually have to let the motors and ESCs cool down.

Is there a "fuel gauge" on the remote so your drone doesn't drop out of the sky?

Telemetry. Yes there is and there's many ways of doing it. Right now I have a osd (over screen display) installed and plan on using that. It will overlay the info on the video captured from the go-pro to a screen on the ground. The down side is you have to constantly look at the screen to seen the info. There is a module you can buy (and I eventually will) that transmits info directly to the remote. The nice thing about that is the remote has audio (high pitched beeps) and vibration alerts. So when I'm getting low on power I can just feel the remote shaking. The more advanced remotes have voice commands which will actually say "low voltage warning".

[atgcpaul]

The flight controller also handles the stabilization, GPS, return to home, follow me and many other operations (depending on the model you get).

What kind of ground speed can this attain? Trying to figure out the total range based on run time. If you can program it to return home with GPS, that probably means you can program it to go somewhere else to, right? What is the payload weight? Man, this is sounding scary.

[jussi]

What kind of ground speed can this attain? Trying to figure out the total range based on run time.

Not sure. The program I use, ecalc, doesn't give out that info. It won't be fast though. I built this rig primarily for aerial AV so I value stability, thrust, and efficiency over speed and maneuverability. I'm using a large frame and larger, more powerful but slow spinning motors which turn larger props. All of which translate to more lifting capacity, stable videos, and longer flight times. If you want a faster copter use a smaller (250 class) frame with smaller but much faster spinning motors turning much smaller props. Video won't be as good but that's not why you build that type of copter. Most guys use the video on those copters for fpv flying using goggles. Beware though I'm not 100% certain on the FAA's ruling on using those goggles. Seemed unclear from the stuff I've read.

If you can program it to return home with GPS, that probably means you can program it to go somewhere else to, right?

Yes. Different companies call it different things but I think most people know it as "way points". You download an app for your given flight controller and then download a google earth map of the location you're going to fly in. You can then click on the map to different locations you want your copter to fly along with the speed and altitude. The last location, normally, your starting point. Alot of people with alot of land use this to map out their property. Farmers also use it to keep an eye on their crops.

What is the payload weight?

Right now 2.3 kg or just over 5 pounds.

Man, this is sounding scary.

But Fun

[woodturner]

Right now 2.3 kg or just over 5 pounds.

Ohh, that's a lot. A couple of things kind of surprised me when we built our first quad for research:
1. It's really, really noisy, more than I expected
2. Flight times are really low - tough to get more than about 10 minutes flight time while carrying a camera and a flight controller
3. Cost to build one is high, commercially available units are much more economical

This has been a few years ago - now we just buy the $50 commercial ones and retrofit our flight controls. I think that first one cost around $500 to build.

[jussi]

Ohh, that's a lot

It is a little heavy but not really when compared to the professional AV rigs which carry actual production quality cameras. Often the Red brand. Those cameras alone are double what my entire copter's all up weight. My ultimate but very very distant goal is to make one that can carry a DSLR camera.

2. Flight times are really low - tough to get more than about 10 minutes flight time while carrying a camera and a flight controller
.

Motors have gotten pretty efficient. Especially if you're willing to spend the money and get one of the premium brands. I went middle of the road and will be happy with 15-18 mins.

3. Cost to build one is high, commercially available units are much more economical

This has been a few years ago - now we just buy the $50 commercial ones and retrofit our flight controls. I think that first one cost around $500 to build.

Yes RTF ones are much cheaper and obviously less work. Curious to which ones you're buying for $50? Only ones I know of in that price range are the Syma type quads.

[ArtworksIII]

Didn't know syma was into Quads. I fly Eflite indoor gym type fun have an old 120sr and CX2. that looks like either fiberglass or carbon fiber. maybe thermoplastic. Some Quads get really large as the cameras gimble demand. GPS to keep from losing the thing and some sort of power back up. good times

[dbhost]

Looks like a fun build. Use it wisely.

[jussi]

Looks like a fun build. Use it wisely.

Absolutely and I think most people do. But unfortunately in every group there are always a few knuckles heads and their actions are the ones who often make the news. Which is both sad and annoying since it not only puts people / property in danger but just makes the hobby look real bad. I probably shouldn't call it just a hobby however, as it has many commercial applications as well. Including search and rescue. For anyone interested, the FAA released an app called B4UFLY which lets you know if the location you're in is safe to fly a drone. Also many of the higher end flight controllers will actually restrict your flight if you're in such an area. The FAA also released a list of laws to follow.

[dbhost]

Absolutely and I think most people do. But unfortunately in every group there are always a few knuckles heads and their actions are the ones who often make the news. Which is both sad and annoying since it not only puts people / property in danger but just makes the hobby look real bad. I probably shouldn't call it just a hobby however, as it has many commercial applications as well. Including search and rescue. For anyone interested, the FAA released an app called B4UFLY which lets you know if the location you're in is safe to fly a drone. Also many of the higher end flight controllers will actually restrict your flight if you're in such an area. The FAA also released a list of laws to follow.

I kind of didn't figure you were the sort that would use one to say bomb orphanages, harass hunters or ranchers on private land, taking peeping tom photos of folks in the neighborhood that sort of thing... I was more going for the don't fly it into the wires kind of thing... While I don't know with absolute certainty, but I have a certain level of confidence in peoples decency here...

Funniest thing I saw with a drone was fairly recent. I guess it is probably only certain ones that do it this way, but if a done loses signal to the controller, it backtracks and returns to where it took off... Which in this case was a public beach, Guy flying a drone, gets up, and walks away from his launching spot. Someone else takes the spot, puts up the beach umbrella, gets out the sunscreen...

And the battery in the controller dies.

Here comes the drone at a less than leisurely speed trying to "get home", and managed to get tangled up in the beach umbrella on its way down, doing considerable damage to both the umbrella and the drone...

So I was really more going for the "enjoy it but use common sense" kind of thing...