Quadrotors and Multirotors

[Shadow10]

Anyone flying these commercially, or know anyone that is?

I got interested in these a couple of years ago with the intention of commercial applications. I decided to take a step back for a while as the development is moving so fast its difficult to keep up.

In the meantime I bought a little quad called a Jump Jet, made in the UK. Its very crash-able, which is good as its a little bitch to learn to fly as it has no automated fly control. Master one of those and you can fly anything.

I'm in Sydney, Australia and our governing aviation body, CASA, jumped on these things very early. There have been some commercial operators working with the regulator, but theres a bunch of regulations that look like they won't budge from:

No flying over built up areas of any kind.
Ceiling height 400'AGL
Pilot must maintain line of sight at all times.

Thats before we get to a bunch of stuff about privacy issues, etc.

The biggest worry is lack of redundancy when something goes wrong. This is also why these things will never be scaled up to carry real people. Also the complexity for such an aircraft makes it cost prohibitive.

[DakarNick]

Originally Posted by biggziff

I was just reading about issues with harmonics using 1.3 and 2.4 together. Any thoughts on that?

I am unaware of any harmonics problems but I will look into it. I tried out both of them in the living room hooked to the TV. I don't have a monitor or goggles yet.

The HT-FPV quad is running a 1258/1280mhz Tx and the pico Tx on the mQX quad is a 1258mhz. The Rx is also 1258/1280mhz.

[Sniper X]

What is the cheapest one of these I can get that will carry my GoPro?

[DakarNick]

Originally Posted by Sniper X

What is the cheapest one of these I can get that will carry my GoPro?

Tri or quad? Home made is cheapest.

$20 in wood and hardware
$30 for flight controller
$15 receiver
$80-100 motors (quad) or $60-80 motors (tri)
$60 ESCs
$20 battery
$20 for wiring harnesses, tape, velcro, etc.
$20 yaw servo (tri)

That is what I have found but you could buy used or use lower-end running gear.

Here is an RCgroups.com link that talks about a cheap kit tri that could easily be made into a quad.

http://www.rcgroups.com/forums/showthread.php?t=1792533

I'm going to build one of these next. I think if I upgrade my quad I'll slap its motors onto a cheap tri-frame and use that for fast, aerobatic flying and keep the quad as a heavy-lifter camera platform.

[biggziff]

Originally Posted by DakarNick

I am unaware of any harmonics problems but I will look into it. I tried out both of them in the living room hooked to the TV. I don't have a monitor or goggles yet.

The HT-FPV quad is running a 1258/1280mhz Tx and the pico Tx on the mQX quad is a 1258mhz. The Rx is also 1258/1280mhz.

I won't claim to fully understand RF theory, but what I've read is that the 3rd harmonic (your signal X2 so 1258 X 2 = 2516) which is in the range of 2.4 used by the TX/RX can be an issue. Some say they have no issues while others say they've lost a plane due to it (or at least they think they have) It's probably more about the filtering ability of the devices than anything else. I've read where many recommend using filters to help with this. Just some data to consider I guess.

Keep us posted on your results. I'm sorely tempted to order that Pico stuff to run on my MQX and Crack Yak... :)

[Chisenhallw]

Originally Posted by DakarNick

I'm going to build one of these next. I think if I upgrade my quad I'll slap its motors onto a cheap tri-frame and use that for fast, aerobatic flying and keep the quad as a heavy-lifter camera platform.

Please post pics of your build as you go!

[CousinLarry]

Originally Posted by DakarNick

I think if I upgrade my quad I'll slap its motors onto a cheap tri-frame and use that for fast, aerobatic flying and keep the quad as a heavy-lifter camera platform.

I am doing the same! I've found the aerobatic limits of the DJI Naza.. I am going to keep that as the FPV ship and build myself a little hot rod tri-rotor. Either that or a V-tail design - those look sick too. Either way it will be aerobatic and fast.

[DakarNick]

Originally Posted by Chisenhallw

Please post pics of your build as you go!

Will do!

[DakarNick]

Originally Posted by CousinLarry

I am doing the same! I've found the aerobatic limits of the DJI Naza.. I am going to keep that as the FPV ship and build myself a little hot rod tri-rotor. Either that or a V-tail design - those look sick too. Either way it will be aerobatic and fast.

Sweet, let's share any ideas that may help eachother

The V-tails are pretty neat! I think I'll try a T-copter with standard servo-driven yaw control.

FYI, non-multirotor guys, a tricopter is a y-shaped multi. A T-copter looks like a T. It's more suited for camera work because it the two front arms are straight, not forward-swept.

I will be at work for snow removal most of tomorrow as we're expecting a blizzard. So, I may as well put the scrap wood in the carpentry shop to use

[Saget]

Any of you guys tried one of these yet? Looks pretty interesting. It's not cheap at $229 with GPS, but that's quite a bit less than the NAZA-M controller. It offers GPS waypoints, position loiter, auto takeoff & land, telemetry, data logging, camera control, etc etc.

http://store.diydrones.com/APM_2_5_N...-apmpwrkt2.htm

[biggziff]

http://www.rcgroups.com/forums/showp...35&postcount=2

Crius Pro still gets a lot of love as the best bang for buck out there....

Originally Posted by Saget

=Saget;20900507]

Any of you guys tried one of these yet? Looks pretty interesting. It's not cheap at $229 with GPS, but that's quite a bit less than the NAZA-M controller. It offers GPS waypoints, position loiter, auto takeoff & land, telemetry, data logging, camera control, etc etc.

http://store.diydrones.com/APM_2_5_N...-apmpwrkt2.htm

[DakarNick]

Well, Chisenhallw asked for progress photos of my build. Like I said, I'm stuck at work plowing. So, between plow rounds I hung out in the carpentry shop at work and built this with scrap wood.

Front arms are 13.5" and each go 3" into the 6" wide body. Rear arm is 15" long and also goes 3" into body. I made a U-shaped slot for the rear to slide into.

Body is two pieces of 1/2" Gatorfoam or Gatorboard and is 6" wide by 14" long. Ends are tapered. It was scrap. Good thing, too, that stuff is over $3.00 a square foot. Entire body was Gatorfoam but I cut the front ends off and glued on a strip of wood for more strength.

I copied an RCgroups.com design, the one I linked to in response to Sniper X's cost question.

Uploading pics in a minute...

It started with a drawing on the white board


Then off to the shop for scrap. This is what it started looking like.






And here is where I am now.

[DakarNick]

Ok, so that last one I built looked pretty good for what I had into it, which was $0 and a few hours work. But it was heavy. 371g (13.08 oz) just for the frame as it sits in the photos. Pretty heavy considering I still need to add three motors, three props, three ESCs, a distro block, battery, FC, servo, yaw mechanism, etc.

I'm going to start over! This isn't just about being lightweight, but super simple to repair and replace. I bought some 6"x1/4" balsa sheet and 24"x3/8"x3/8" basswood square stock.

I'll take some pics as I build.

[DakarNick]

I feel like I'm just talking to myself, lately

But here are some progress pics. Well, all the pics, really. I didn't stop to take any pics during the build because I am bad at it and usually forget.

It is simple and the pics will show this.

The front arms fold back for ease of transport.





Tri-copters have three propellers, so that means they will have extra torque in one direction, depending which props you put where. I will be putting two clockwise props on, one on the left front and one on the rear. The right front will be counterclockwise. The front of the T-copter will want to yaw to the right. So, some right cant (angle) will need to be built into the rear prop to bring the tail to the right, the front to the left.

Yaw mechanism. Servo rotates it on one end. The other end is a 4mm bolt going through a bearing.



More pics as I upload them, stay tuned.

[Chisenhallw]