How to get started in single rotor AP?

[NicolasArg]

Hello board, this is my first post here but I've been reading the forum for several days now.
First of all a little background- I live in Patagonia, and have been shooting video for stock for some time. I'd like to get into AP for those unique angles and compositions. The most direct and frequent recommendation these days is "just get a phantom" or, being an avid RC modeler "just build a hex", but I'm not sure a multi is the aircraft I'm looking for.
Very calm days are very rare here and I frequently trek up in the mountains and local hills (+- 1500/2500m asl). I've been reading a lot about multis for several weeks and playing with ecalc; and the flight times vs payload for small quads in sustained winds are not looking good. Having a single large prop appears to be a logical solution.
The problem is that there is a lot of material on the web about multi AP but I can't find any beginner guide for single rotor; some sort of "getting started".
What would you gentlemen recommend? Is the single rotor still a valid approach for the task? What could be a budget basic build for a gopro/gimbal setup? Is it comparable in terms of $$ to a multi of similar size?
If it helps somehow to answer, I've never flown a heli but been flying 4ch planes for a couple of years, have my own workshop and access to fully equipped cnc shop for DIY, repairs, etc. Of course willing to invest the necessary time to learn to fly a heli.
Thanks in advance for your time,
Nicolas

[nocontrol1]

Hi Nicolas- I've flown both single and multi's, you really should consider a multi. The technology has matured nicely, and the advantage of mechanical simplicity is hard to beat. I've flown a 810mm hex in 30mph winds, it had no problems. Flight times were about identical for the 810 and a Trex 700 I had before that used the same batteries. The Hex was much more stable and all around much less stress to fly than the single rotor. I was using a Naza H on the single, it was great, but the features on the multi controllers are stunning.
Don't forget the single rotor has a steep learning curve just for setup and maintenance, and it's really important! Check out the DJI Phantom 3. It handles wind pretty well, and is a really good bargain for what you get. Good video and photos, great range, solid downlink, telemetry, and the ability to adjust the camera on the fly. And best of all the whole thing will fit in a backpack.

Rob D

[NicolasArg]

Hello Rob, thank you for the info and sound advice. I've been looking at the P3 for a while now and it's frankly great, I guess the only reason I didn't buy it already is psychological- as a kid I started with band powered balsa planes and progressed all the way up to high power rocketry.... hard to just join the "paynflylikeanexpert phantom revolution"
Your 810 hex sounds really interesting, is it a DJI 800 or a tarot 810 frame or something similar?
Oh and one more question, in case that I do take the hard road towards single rotor ap platform, what would be a logical progression? I suppose something similar to a Trex 450+a lot of practice > more practice> 700 heli?
Thanks again!

[nocontrol1]

I have a Tarot 810, selling it off as the P3 is so easy and portable.The Tarot is a nice, beefy airframe that is real tough. Sim time is key for single rotor. I did the worst of the learning curve on an old shuttle .30 sized nitro. Graduated to a .60 Raptor, then to the Trex 700. The learning curve was slow and expensive without a sim, it's definitely money well spent. Get to where you are automatic in all orientations before thinking about flying AP/AV on a single.

Rob D

[helicek]

Hi NicolasArg,

I fly helis and multis for photo and video.
the camera that comes with P3 is good. It will almost match most standard non-fullframe cameras. Light bridge is olso very good too. All that stuff works no catches either.
With P3 you will need to pirouette the multi if you wanted to shoot panoramas.

In my personal opinion the only problem with DJi and similar stuff is that they introduce a new model (or an upgrade) every other month. You will need to keep getting their latest model or whatever else you are obsolete.
Cheers,
Ahmet

[Goldenhour]

I'm not sure I'd even get into the aerial part of copters. The pictures look cool but damned, trying to get a good picture and keep everyone happy. I've been chased out of many private property, after I got the picture. For sure single rotors are about as deep as getting an associates degree compared to a 4 credit class for multis. They singles really do take a lot of maintenance gear and education to get it right.
Its like a multi is a performance car with an automatic transmission. The single rotor is a performance car with a manual transmission with a stage 1 clutch. Want thrills?
If I were you I would stay away from copters unless it is JUST for fun. If you have dreams of creating a business you have a very long hard road ahead and slim odds of ever making it pay. I've seen the ads pimping video, movies, get the shot. Its all marketing to get your hard earned money. And once you spend your hard earned money on any copter you will never get even 60% of what you paid. If you could sell it at all.
Put your money in a 401K. Your gonna need it long after the dot com copter sellers have retired.
Edit: I'm not angry just think marketing and ignorance has bought many a white elephant for people. I just bought a heavier gimbal for my heavier camera that I will test soon. I've spent over $12,000 on well...........what did I buy? Fun and diversion. A sense that I'm creating, a feeling like adrenaline rock climbing where you don't get a second chance if you screw up up there.

[NicolasArg]

Rob, Ahmet> thanks for your posts, really helpful!

Originally Posted by Goldenhour

Its like a multi is a performance car with an automatic transmission. The single rotor is a performance car with a manual transmission with a stage 1 clutch. Want thrills?
If I were you I would stay away from copters unless it is JUST for fun. .

Thank you, I think I've finally made my mind after reading the boards, watching a couple of DVDs and talking to a local RC heli pilot who basically told me the same thing.
Since I'm already shooting video for stock, I'll get into multis, just to have a small and robust AP platform for some unusual local angles.
I do like the idea of learning RC single for fun and challenge so will be probably getting an entry level copter, perhaps one of those small (400-450) ARF kits.

[R_Lefebvre]

I think starting AP with multirotor makes a lot of sense, but if you want to get serious, it's worthwhile exploring helicopters too. There is an undercurrent growing in the industry that for many applications, helicopters are just far superior to multirotors. This is true any time the operation requires operating in winds, flying long distances at speed, or lifting heavy loads for long periods of time.

There's a lot of misinformation and confusion in the industry. Chief among them that helicopters are "hard to fly". Nothing could be further from the truth if you compare apples to apples. That is, put the same stabilization electronics on the helicopter as the multirotor has.

I call BS that a multirotor can handle winds as well as a helicopter. Somebody please show me a Phantom (same weight class as this heli) doing this:

Arducopter TradHeli Wind Demo (1 min 42 sec)

To the point on ease of flyingt, most of that was basically hands off. I was holding the camera at the same time as controlling the heli.

Does this really look like race car to you?

Arducopter 3.0 Helicopter Demonstration (13 min 58 sec)

[NicolasArg]

Hello Rob, thanks for chiming in (sorry if I'm not using correctly the "chiming in" here, a bit hard to make sense in a foreign language )
I was actually reading this:
http://diydrones.com/profiles/blogs/...lti-rotors-and
When I logged in to helifreak and saw your post. Very interesting, and very impressive videos.
So far, I've seen that in almost every discussion about multi vs single AP/AV platforms, large, 800 class helis with cine cameras are compared to tiny, phantom sized multis. So, several questions come to mind:
1) Is it possible to create a stable gopro heli platform with a flight controller in 450-550 size?
2). What approximate flight time could be achieved with such an aircraft?
3). What would be a viable model-kit for such a platform?
I mentioned 450-550 class because of size, price and moderate cost of replacement blades/parts.
Thanks for your time!

P.S. If it helps (just to add some geography reference), this is my hometown; mountains and winds included. So far it's ideal for the planes I'm flying....
https://www.google.com.ar/search?q=t...IVg0GQCh3JaQg4

[R_Lefebvre]

Yep, good questions. And you're right, everybody looks at large helicopters for carrying big cameras, declares them too dangerous, and ignores the possibility of a smaller copter.

The mapping helicopter I showed is a Protos 500 stretched to 475mm blades. This would probably do a very nice job carrying a GoPro on a light weight gimbal. I've actually been wanting to make something like this, but haven't found the right build target yet. I like many things about the Protos, but I don't like the plastic head parts. I know they work fine, etc. etc but... meh. I also have looked at a Trex 500, actually I have one. But I much prefer the belt drive on the Protos. I need to make a hybrid, just never gotten around to it.

But yes, the 500-stretch to Goblin570 size would make really nice machines.

And believe me, a 500 heli turning only about 1800-2400 rpm is much less intimidating than the larger helicopters. The low RPM really improves safety, but nobody considers it.

So flight times, I think I go into details in that blog post. But at 3400g AUW including 2 4S 8000 batteries, flight time was around 30 minutes IIRC. That was including the large subframe.

Since then, I took that heli "back to basics" and removed the subframe, mounted the S100 on a skeleton frame as small as possible, and using a single 4S 8000 it still flies 20 minutes. Total AUW is 2050g.

So that should give you some ideas of what you could expect.

[NicolasArg]

Originally Posted by R_Lefebvre

So that should give you some ideas of what you could expect.

Yes, thank you. And just one more question about the stabilization electronics you mentioned above. Is a simple (that is cheap) FC like the cc3d or Naze32 a good place to start or a more advanced board is needed (for line of sight stabilized flying, with no GPS)?
And a corollary: I've seen that some basic heli kits are sold with a FBL system, do they work along, or a stabilization FC renders the FBL system unnecessary?
Thanks!

[R_Lefebvre]

I don't think cc3d or Naze32 will fly a helicopter. If they do, I'm pretty sure it's rate only.

APM:Copter (aka Arducopter) is the only program offering full features like that for a helicopter. This can run on several different hardware types, none of them very expensive. I recommend the 3DR Pixhawk. I have used the AUAV-X2 on smaller copters as well.

You do not use a standard FBL system, the Pixhawk does it all.

[NicolasArg]

I see, thank you Rob, think I'm more or less ready to try it now.

[zurgxd]

Originally Posted by NicolasArg

What would you gentlemen recommend? Is the single rotor still a valid approach for the task? What could be a budget basic build for a gopro/gimbal setup?

It doesn't have to be complicated, you could just bolt a camera onto the skids and start taking pictures. Works flawless. I don't see the need for a gimbal, but I guess it depends on what you want to accomplish.



FPV is also useful to get an idea of what you're photographing, preferably with OSD.

[felixthemaster]

Any tips on attaching to skids? I have been thinking about this all day, trying to fit my gopro clone on my 360CFX without getting extended landing skids to fit cam under the heli

[NicolasArg]

Originally Posted by R_Lefebvre

But yes, the 500-stretch to Goblin570 size would make really nice machines.

And believe me, a 500 heli turning only about 1800-2400 rpm is much less intimidating than the larger helicopters. The low RPM really improves safety, but nobody considers it.

So flight times, I think I go into details in that blog post. But at 3400g AUW including 2 4S 8000 batteries, flight time was around 30 minutes IIRC. That was including the large subframe.

Well, I've just got the chance to see a 550 class heli in person and even given the extended flight time it's a beast in terms of size and logistics when compared to a 350-450mm multi or 90-100cm fixed wing that can also carry a gopro.
So if we are thinking in terms of low weight payloads (like a vibration isolated gopro for cattle control or something along these lines) a 450 class would be an ideal size, but from what I'm seeing in specs and playing with xcalc the flight times are not that great.
I'm missing the catch here, how is it possible that a low Kv motor spinning a 0,5sqM rotor has less flight time than a phantom spinning 4 rotors with a total surface of 0,16sqM.
SOmething like this perhaps?
http://www.rcgroups.com/forums/showthread.php?t=1620106

[NicolasArg]

Originally Posted by zurgxd

It doesn't have to be complicated, you could just bolt a camera onto the skids and start taking pictures. Works flawless. I don't see the need for a gimbal, but I guess it depends on what you want to accomplish.



FPV is also useful to get an idea of what you're photographing, preferably with OSD.

Hi, did you try filming with this setup? Do you get a lot of vibration?

[R_Lefebvre]

Originally Posted by NicolasArg

Well, I've just got the chance to see a 550 class heli in person and even given the extended flight time it's a beast in terms of size and logistics when compared to a 350-450mm multi or 90-100cm fixed wing that can also carry a gopro.
So if we are thinking in terms of low weight payloads (like a vibration isolated gopro for cattle control or something along these lines) a 450 class would be an ideal size, but from what I'm seeing in specs and playing with xcalc the flight times are not that great.
I'm missing the catch here, how is it possible that a low Kv motor spinning a 0,5sqM rotor has less flight time than a phantom spinning 4 rotors with a total surface of 0,16sqM.
SOmething like this perhaps?
http://www.rcgroups.com/forums/showthread.php?t=1620106

It's not possible. That's my point. Helis fly longer when set up properly. The problem is, most aren't set up properly. The Phantom has been engineered and evolved or 3 years by a company worth billions of dollars, with 100 engineers.

Most helis are designed by companies worth maybe $1M, employing maybe a single engineer, or even just a community college CAD design diploma.

I disagree with your logistics statement. First, a 350-450 quad is not at all comparable to a 550 Heli. And I'd disagree that a 550 Heli is logistically more difficult to tote around than a 1m airplane. Particularly if the plane is not a simple 1-piece flying wing. Also, the airplane cannot perform the same mission a heli can, in the same weather conditions.

I've got winds gusting to 50 km/h here, and I'm about to go do test flights on a 380 heli. Nobody would be flying an airplane in this weather.

[zurgxd]

Originally Posted by NicolasArg

Hi, did you try filming with this setup? Do you get a lot of vibration?

I mainly did this for still photos, but yes I did try a few videos. There is some jello and small vibs, it could probably be eliminated if I wanted. Also depends on head and shutter speed.

Here's a video still
j84w8.jpg

I made some dampening things between the mount and arms, with rubber "pads" and hot glue, to adjust the stiffness.



Could have been done a lot better but this works good enough for me.