Two clients want me to fly their RED EPIC cameras - advice?

[ghaynes]

Benjamin

Got a note that the KW8's will be back in stock later in the month. in eCalc take a look at the Tiger MT2814-10 using 4s and the 14x4.7APCSF props. It looks like a good combination. Just haven't seen to many folks posting about the MT2814-10's. Other MT2814's but not the 10's.

 

[R_Lefebvre]

Come to think of it: Test lift-off with one motor purposely made unfunctional (disconnect a wire or something)?If the octo can go up, even in a not too stable way, one would think that would garantee a somewhat controlled landing in the event of a real failure in the air. Anyone tried this? Doubt a closed source FC like DJI's would let one do this, I'm going to try this with mine though one of these days.

Well... maybe it's not so simple. I know at least in our case, the quads can get a little wobbly coming down, since they are descending into their own downwash, which is turbulent and causes wobbles. Getting through that on the way down with a motor out will be harder to do than going up.

 

[Benjamin Rowland]

Benjamin

Got a note that the KW8's will be back in stock later in the month. in eCalc take a look at the Tiger MT2814-10 using 4s and the 14x4.7APCSF props. It looks like a good combination. Just haven't seen to many folks posting about the MT2814-10's. Other MT2814's but not the 10's.

The MT2814-10 has some good specs. They're very similar to the QC3328 motors I'm running now, which are great motors. They'd probably get too hot in this boiling Atlanta summer though if I was pushing them with a 10 pound payload.

 

[DucktileMedia]

I just did a test run with my XY8 using Tiger 2814/11 and APC 14"x4.7's on 4s and they are hotter than they have ever been. of course I usually run smaller props with a much larger load. but now I am lifting 4lbs of additional weight. the av200/360 with all its accessories and just a nex5n adds up quick. I have never smelled the oils burning from the motors before. I can grab them but they are still warmer than normal. Im using the Hoverfly pro. I wonder if I had the flat octo if that gain in efficiency would help out noticeably.

 

[jes1111]

I just did a test run with my XY8 using Tiger 2814/11 and APC 14"x4.7's on 4s and they are hotter than they have ever been. of course I usually run smaller props with a much larger load. but now I am lifting 4lbs of additional weight. the av200/360 with all its accessories and just a nex5n adds up quick. I have never smelled the oils burning from the motors before. I can grab them but they are still warmer than normal. Im using the Hoverfly pro. I wonder if I had the flat octo if that gain in efficiency would help out noticeably.

IMO - no, not noticeably - the additional thrust would be more or less cancelled out by the additional weight. What could make a worthwhile difference is higher pitch props on the bottom - like JXF 14x4 on top and 14x5 on the bottom. (In eCalc I enter this as "14x4.5", i.e the average pitch.)

 

[Digitech]

i would even go smaller

we run 2814 on a hexa with 4lbs load dual 5S
and 11x5 graupners

 

[ChrisViperM]

Ben, in case you have not seen this video yet...it's only about a Cinestar 6, but still interesting:

http://vimeo.com/42225781#

Chris

 

[ChrisViperM]

Another good comparison of different motors I have found here:

http://www.rcgroups.com/forums/showthread.php?t=1388583

...just hope Bart doesn't kick the link out

 

[arif2209]

hi jdennings,
actually i have tried your method of testing the motor. i forgot to connect motor no.4 cable to the esc. the first 2 minutes i did not realized that 1 motor disconnected. it flew great. only after about 2 minutes i noticed that 1 prop not spinning and i quickly land it. i am flying cinestar 8 with MK, herkulesII, KW4 motor, APC 14x4.7. i carry canon 5d mkII with sigma 10-22 lense. i think if 1 motor gone, u cannot feel it. because i did a lot maneuver for the first 2 minutes. i can only hear the other 7 motor sound louder a bit.
anyway that was my experience. hope that help.

 

[sim_io]

Another good comparison of different motors I have found here:

http://www.rcgroups.com/forums/showthread.php?t=1388583

...just hope Bart doesn't kick the link out

I don't know why he didn't use the same props, he used 11" for the avrotos and 14" for the axi of course the axi will lift more because of the bigger prop but its not a really useful comparison.

 

[3dheliguy]

Hi All,

I just wanted to hand out some advice from the other side of the tracks, and I'm not putting anybody's setup down, but I would just like to let People know my experience with castle creations and heavylift setups but from a helicopter stand point. And I do understand that we are not maxing Amps with these systems, but we are sending tens of thousands of dollars in the air and we want reliability. This is just from experience not bashing or putting the escs down, just experience.

I am expert 3d helicopter pilot sponsored by a big orange county heli shop in Orange county CA, I have been flying for 5 years, and tested hundreds of setups with all different kinds of components. We test to try to find the most reliable setups for the money and expense. So basically we fly till it breakes or has a problem in witch we try to recover land or auto down, but if you know 3d helicoptering then you will understand how hard we push these system. But I have to say that as would never tell a customer not to by an item I would still speak of experience when I say out of all the ESCs I have tested I have had the least amount of luck with the castle creations line of ESCs. I have repeatedly burned and melted electrons due to these escs catching fire, and creating
An irrecoverable crash worth thousands of dollars.

So I really just want to through that out there in saying please check your setups to make sure you are not overamping these
Speed controllers as they in my experience burn a lot more than just themselves, and make sure you get some head room in your escs so they are not at there peak amperage.

Also I know what your going to say, what was the most reliable speed control to date.... This would have to the Kontronics line of ESCs from Germany. They have worked flawlessly time and time again, also the YGE speed controllers are an excellent choice for these application. Keep in mind this really only applies to the heavy lift individuals that are really looking to carry a crazy amount of weight.

I'm an currently in the process of figuring out how to build my heavy lift kit. So on this end of the scale I'm still very much a
Beginner. I'm not a photographer, but I learn fast so I'm building a rig to make a couple bucks on the side I hope, but there's a lot to it, and I know you guys are trying to domthe same so I wish you all the best. And thanks for all the interesting points of view and techy insight, as I have not actually tested the setup I'm thinking.

Just so you know setup I'm thinking. Chime to help

Droidworx SJ8 or Cinestar 8
Axi 2826
May tech 60 amp esc as I have heard good things, and I'm firmly believe in following the crowd on what worxs...
DJI wookong M. Love this system since day one.
Custom disrto board. Solid copper drilled out.
Av200 or Cinestar 3 Axis.
RSGS or radian when proven.
15 or 14 xoar props wooden

 

[3dheliguy]

Wow that is a great point. Since I come from the heli 3D side I totally understand your nuclear power plant Joke. That leads me
To this point, the electric era is coming beit it takes a bit longer for battery power to catch up with fossil fuels you know one day
Soon that Gasser will succumb to the electric heli. It's only a matter of time, usually battery tech advances heavily every 10 years or so, and we know the tech is here it just hasn't filtered down to us the public. So for know the gasser might be up there for longer period of time, but that's it a matter of time.

Can't wait electric is Awesome, and a lot better for our environment.

 

[PaNt]

3dheliguy.. You are right about helis..! But in MR world CC is very good because the AMP draws are max30A...

On helis AMP draw is minimum 70 and max 150-200A..! Thats the difference!

 

[DennyR]

The electric heli is the most efficient conversion of electrical power into lift. Unless one has a problem flying a large heli with something like a Wookong H or a SkooKum flybarless controller. (which has a position hold that is at least as good as any MR) Then the underlying question is WHY use a multirotor. The heavier the lift requirement then the more important is the need for efficiency and reduced electrical failure points. It really is no contest. If all you want is to fly around with a GoPro then a MR is a cheap way to have a lot of fun. It will not have as good performance in strong wind and it will use a battery voltage that will cause high temps, plus it has low aerodynamic efficiency. T Rex 800 is coming as a special AP system but if you want the best then it is something like a TDRigid with 710 asymmetric blades running at no more than 1250 RPM. Speed, endurance, reliability and a visual maintenance schedule that does not require a degree in EE. Mechanical parts have a reliable life span, electronic parts do not, at consumer level. Whilst we spend most of the time on this forum discussing the hundreds of day to day problems with MR's people are out there flying and only crashing when they push the limits. The ESC is the most likely failure point with all electric models. That is why I don't see a problem spending 500 euros on a quality product from Kontronics.:tennis:

 

[PaNt]

The electric heli is the most efficient conversion of electrical power into lift. Unless one has a problem flying a large heli with something like a Wookong H or a SkooKum flybarless controller. (which has a position hold that is at least as good as any MR) Then the underlying question is WHY use a multirotor. The heavier the lift requirement then the more important is the need for efficiency and reduced electrical failure points. It really is no contest. If all you want is to fly around with a GoPro then a MR is a cheap way to have a lot of fun. It will not have as good performance in strong wind and it will use a battery voltage that will cause high temps, plus it has low aerodynamic efficiency. T Rex 800 is coming as a special AP system but if you want the best then it is something like a TDRigid with 710 asymmetric blades running at no more than 1250 RPM. Speed, endurance, reliability and a visual maintenance schedule that does not require a degree in EE. Mechanical parts have a reliable life span, electronic parts do not, at consumer level. Whilst we spend most of the time on this forum discussing the hundreds of day to day problems with MR's people are out there flying and only crashing when they push the limits. The ESC is the most likely failure point with all electric models. That is why I don't see a problem spending 500 euros on a quality product from Kontronics.:tennis:

Dont forger the logo 600SE streched.!!!Its a very very very smooth heli that can fly from 1000-1950 rpm!

 

[DennyR]

We have a few Logos in Cyprus flying 3D, They are very good at what they were designed to do. That frame does not lend itself well to conversion for mounting a decent camera mount. IMHO. I see only disadvantages with no real advantages. Nice machines though.

The difference in efficiency between 1000 rpm and 1950 rpm is going to be about a factor of x3.5 even though you are just hovering. Aerodynamic drag is a square law. Think about the tip speed and how far it is from the hub. The Asymmetric blades have less pitch angle at the tips and also have center of mass further out to aid autorotation and blade rake. Very big improvement when you don't need to go upside down or have very fast response for 3D.

 

[R_Lefebvre]

As a guy who's been working on doing this with both MR and SRH's...

The advantage of MR's is extreme mechanical simplicity. They have 4-8 moving parts, and that's it. Also, the vibrational frequency they generate is high, and thus fairly easy to mitigate with vibration damping. It might appear that they have more electronics which can fail, but I don't think that's true. They are just dead nuts simple, and IMO, more reliable because of it.

SRH's may appear to have only 1 ESC, but each servo actually contains a tiny ESC, and just as with MR's, any of them can fail at any time, and there's not much you can do to predict or prevent that, just as with MR ESC's. Difference is, a good Octo MR design should be able to land safely with an engine failure. On a SRH, if any of the servos fail, it's coming down. And if the main ESC/Motor should fail, technically you could autorotate down, but if you're carrying a heavy load, hovering 20-50 feet off the ground as typical, good luck with that.

Also, the vibrations produced by the SRH are much lower frequency, and this makes it harder to damp the vibration because the frequency spread between the mechanical vibration, and the inertial movements of the aircraft are much closer. It's very difficult to eliminate the vibrational shaking, without getting into two-mass oscillation between the camera system and the airframe.

SRH's have an advantage in efficiency, flight time, payload, airspeed and possibly stability. Basically, they perform better. But everything else about them is a big disadvantage. It's conceivable that a novice could successfully assemble and fly a quad with a camera on it. That's impossible with a SRH. They are simply far too complex.

I'm working on both platforms, but plan to take advantage of their unique strengths. For day-to-day use, low winds, slow movements, an Octo. For higher winds, or higher speeds, longer range or flight time, an SRH.

 

[DennyR]

If I had to risk my investment on the chances of a high quality servo failure against a HobbyKing ESC I know what I would choose.
I think the whole idea of open plan MR electronics throughout the entire control system just about sums up the level of development that has gone into this. It is a playground for electronic geeks to fart about with in private and should have no part in serious aerial productions.

If SRH are too complex how come almost everybody who builds one has success with it They quite often come semi built needing only a simple to follow instruction manual. A couple of hours on a simulator and you are ready to go. If MR's were at that same level then this forum would not be packed out with problem debates that even the manufacturers cant solve.

Vibration is not a problem if you know what you are doing. Even gassers can run trouble free with a Zen. Just my 2cents....

 

[R_Lefebvre]

I don't disagree with what you are saying, a top quality helicopter build can be very reliable. My comments are mostly targeted towards novices, hobbyists, and new professionals. If somebody wanted to get into this professionally, with no previous experience, it's going to be a long and bumpy road doing it with SRH's. Even if you have a lot of money to throw into the machine, building it, setting it up, and flying it are much more difficult.

Safety is another factor. A large SRH is easily capable of killing somebody instantly if it hits them. MR's, not so much. They are dangerous, but the nature of the injuries is much different. Multiple slash wounds vs. complete dismemberment. Of course that's a double edged sword as many people think MR's are completely benign and fly them accordingly. I'd love to do something like Myth Busters, get some cheap machines and crash them into a pig carcass to show what happens. I think a lot of people just don't get it. Want to see something terrifying?

I'm going to be attending a Maker Faire to demonstrate this stuff on the weekend. They are going to provide a 30x30 foot area to fly in, but I'm not sure what I'll do with my little quad. My 600 heli I don't even think I'll fly at all. I've thought about tethering it with a 10 foot line, but I'm not sure that would make it "safe". I'd rather demonstrate flying a little foam airplane around, but they think that's more dangerous... I completely disagree.