What is the difference between airframes?

Pumpkinguy

Pumpkinguy

Member
I'm researching a build so please excuse me as I have been asking a lot of questions.

So many of the pro rigs use very costly airgframes. Skyjib, cinestar, syndrone, gryphon etc. When it comes to frames what are you really getting for that premium price versus say a more affordable brand like Tarot?
Let's say we equip a $2000 frame with all the same components as a $500 frame, do you end up with a better product? IE, video and picture quality?
Is the platform more stable? (Less flex).
 

Av8Chuck

Av8Chuck

Member
There are a lot of variables. The place to start isn't with the components you want but what is the problem your trying to solve, what's your mission. Its also not good enough to say aerial photography, AP is all over the map as well.

So what level of quality of imagery do you need - dictates the type of camera - which dictates the amount of weight and how much stability - how much articulation does the gimbal need - which tells you how big the frame, props and motors should be, etc..

Also your flying experience plays an important part in the decision, if you don't have a lot of experience flying AP then DON'T spend a lot of money buying the latest and greatest just because you can. Despite what a lot of manufacturers and people on these forms might say the flight controllers, especially if their being used on a larger, heavier Hex or Octo are no where near plug and play and not reliable enough for a novice. Start small learn how to fly really well line of sight and how to get yourself out of the trouble your invariably going to get yourself into.

Then once you have the experience you'll see that many of the choices people make as to which frames and components to use comes from their own personal experience, their need, if they travel a lot how easy is it to pack up and deploy, how rigid is it with heavier loads, what features they really need. A tarot might be a good frame for some and not others. If your flying every day, the MR is in and out of cases, set up quickly and just flown then its probably not going to be rugged enough. plastic parts will break, metal parts will wear and the whole thing will just become kind of loose. That doesn't mean the Tarot isn't a well built frame but it might lack certain quality parts for such a demanding job. On the other hand if your only taking it in your car once or twice a week and you tune it up occasionally it might last forever.

But only you know how you want to use it.
 



Pumpkinguy

Pumpkinguy

Member
Yes. Execellent advise Chuck. Thank you.
I am kinda at a crossroads. I have many hours on my phanton. I want to build a larger machine. Want at this point, not need. I am one of those guys that thrives on researching, designing and constructing things and I get a great sense of satisfaction from this. I'm thinking a winter project. The problem is I have never flown anything larger than the phantom. My idea is something that can lift most dslr's. Like the s900 maybe towards the size of the s1000.
 


Av8Chuck

Av8Chuck

Member
It still comes down to what problem your "really" trying to solve.

If a MR is setup and tuned correctly then as long as you don't go nuts with the size then its not going to fly that different from your Phantom. Generally the flight characteristics are noticeably different between controllers and not so much frames. Depending on how much you want to spend and how long you want to take researching and building I'd recommend and interim step with a MR that can carry an NEX or GH4 on a 2-axis gimbal. At the very least a 450mm sized quad that you can tune up well and try different controllers so you can get a feel for the differences.

Its easy to get caught up with this component versus that one etc., but if your hoping to get serious about AP then the "REAL" problem your solving is working with whatever brand of controller and components long enough so that you can "TRUST" it. The real problem with the Phantom isn't whether it flies away, but that new pilots tend to get way overconfident way too quickly. That's not DJI's fault nor is it necessarily the new pilots fault its just symptomatic of lowering the barrier of entry so far.

Prior to the Phantom, actually the 330X people pretty much had to build their own, most of the components on MR's were repurposed from something else and nothing seemed to be compatible. It was a real pain in the butt, but I wouldn't trade that experience for anything. Now we're starting to see second generation parts manufactured specifically for MR's, the controllers are more sophisticated and the frames are lighter and stronger but I'd still recommend that you buy a couple of different inexpensive frames and try several different ones. If you move the components from one to the other, that helps you get better at flying and getting a "feel" for how they fly and it will be self evident on which combination you want to scale up for larger payloads.
 

R

RCJardin

Not so new and improving
Well done Chuck. Your replies reflect the realistic ways of the MR world. Also camera technology dictates the size now. I am sure that GoPro4 or in another year 5 will certainly satisfy most applications for most clients/users other than top end broadcast/movie production.
 

Old Man

Old Man

Active Member
Chuck has it together in how he's been laying out history, needs, and requirements. Probably most would never need frames much larger than a 650mm or 700mm if they never intended to gravitate to large heavy payloads. It's really amazing how much versatility an MR in the 700 size really is. One can handle a GoPro and similar, NEX, FLIR, some Lidar arrangements, agricultural applications, and Pix4D with a relatively long duration 600mm-700mm sized MR. That list expands even further once an individual researches other specialized payloads. As Chuck mentioned, what someone needs/wants to do with one establishes many of the features that would need to be on or part of the frame. Those wants and needs also dictate the necessary rigidity and arm layout.

As he mentioned, trust/reliability is key to purposeful operation. A lot of time is spent in determining an MR will remain in predictable control before becoming functionally useful. Based upon all that I think a general MR working platform would fall into a 550mm to 700mm range with how it's all laid out determined by the use intention.
 

gtranquilla

gtranquilla

RadioActive
IMHO - I get the impression that the flat Octo is on it's way out based on the following:
1) Stability algorithms in the Hex now enable the Hex to land safely even with the loss of one motor, esc or prop.
2) Larger Hex motors, props enable a large Hex to lift as much as an earlier flat Octo.
3) Flat Hex configurations are more efficient that the flat Octo such that for a given payload weight, the Hex will have additional flight time. (disc loading concept)
4) As the cost and weight of HD cameras continues to drop, the need for the moderate additional recoverability of an Octo becomes less critical.
5) A Hex is less complex which means more flying time relative to extra time needed for pre/post flight checks and maintenance for the typical Octo.
 


J

jdennings

Member
X8 for me because of redundancy and size but I am aware this is (infinitely) arguable (vs Hex and flat 8). Yes a bit less efficient but smaller size vs Hex and more lifting capacity/endurance (at comparable size) is more important to me. All goes back to Av8Chuck earlier responses though, these should be made a sticky ...
 

R

R_Lefebvre

Arducopter Developer
Yes, it all goes back to Chuck's comments which were great. Particularly the point about identifying your goals and requirements first, then designing from the ground up to meet those. Just as I discussed in my video. And then when you do that, you'd see than an X8 is not less efficient than an Octo. ;)
 

kloner

kloner

Aerial DP
I personally like all the levers on the flat configs versus minimal levers with more power.... makes all the non aerial looking shots possible. we can look up quite a ways without them or, can really push it into FFF and look forward. it's only important when you have to get a shot and can't because of that
 



jfro

jfro

Aerial Fun
R_Lefebvre said:
That is a valid point.

But you can build a "dead cat" X8 and not have that problem. ;)
Click to expand...

Excuse my ignorance, but what is a dead cat x8?

My best guess would be the gimbal mounted on rails out front of the main body of the x8 then counter weight that with batteries on the other end of the rails, ie camera/ head out front and batteries/tail off the back......

If my guess is correct, what is the downside of this config.
 

kloner

kloner

Aerial DP
Dead cat is like a discovery frame

I had an xy8 and it was pretty much that,,, it was "alright"

The biggest problem form a selling point is when people see an x8 they think it's a quad.... you can have an x and a flat sitting side by side and if there window shopping, there gonna give the flat guy the money a lot more till there educated that they both have there place. The ultimate would be to have one of each. I hated working on mine, installing props was a hassle, couldn't get it up on my racks like i was used to because of al the props top and bottom. It was generaly a pain to work with, travel was a pain and i never broke so many props with hanger rash than that thing did. the multiple motors on one arm that is already "soft" just doesn't seem like something i wanna mess with at the weights we moved onto, but in a small rig like a disco, i could easily see it having a huge benefit. I'll have to try one, been meaning to
 



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