FlyingWings Venturi FPV Evo

[dp106]

Lol sorry. Not managed to get yours fixed yet then

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[Sheldon Holy]

Nah, just gonna get a new kit. I'll have a go at making the wings removable - seems easy enough with minimal weight gain.

[iPeel]

Nah, just gonna get a new kit. I'll have a go at making the wings removable - seems easy enough with minimal weight gain.

Will reserve judgement with interest...

[Sheldon Holy]

Here's my plan:

Do away with the standard extruded spar. I'll then get a woven spar of the same diameter, along with another woven tube that has an inside diameter of the outside diameter of the spar. The hole inside the wing for the spar will be enlarged with a hotwire to accept the larger tube, so basically the larger tubes are used as sleeves for the spar to sit inside and act as a wing joiner. Then liteply wing caps will be made for the wing roots with alignment pegs. The wings will simply slide on to the spar and be affixed with screws. The woven carbon tubes are lighter and much stronger than extruded ones so it shouldn't add too much weight. The way Flyingwings uses a single straight tubular spar lends itself to this idea IMO, and I'm surprised they haven't looked into doing it themselves.

[iPeel]

TBH it's not been considered because it's not been an issue and nobody's complained so why complicate things? The Venturi fits across the back seat of a VW Golf which is a good enough test in my book.

Adding additional spars and fitments complicates the build and increases the cost of the kits. When you start making the wings detachable you also have to make the wiring out to the devices on the wing detachable, which adds more layers of complication in itself.

The box section that the wings seal against is also a stress member, you will have to take that into account with the load calculations on the existing and probably add an additional spar a-la Z3.

I'm by no means trying to dissuade you here, I'd only do that if I thought your idea had no legs in it at all. You're a clever chap and if this feature's important to you I'm sure you'll engineer a good solution.

[gr4ndp4]

My build is going slowly (gardening) I notice the elevon horns on most photos are only about 25% out from the inner ends of the elevons. Is there a reason for this choice, I would have thought this might result in flutter or excessive torque at the outer ends. Would anyone like to comment!!

Cheers

[iPeel]

Once the elevons are laminated they're really quite stiff. Additionally you should fix the control horns as close as possible to the hinge line, so there's very little flex along the length of the elevon.

[gr4ndp4]

Thanks for the advice, I understand the need for the horn fulcrum to be over the hinge (or as close as possible) and the benefit the elevon gets from the laminate. I will also ensure the control rod is perpendicular to the hinge line. Unless there is a particular reason to place the horn 10 cm from the inner end I'm tempted to place it closer to the centre of the control surface (the elevon is 52 cm long)

Cheers

[Brucey]

I can't think of a reason other than keeping the weight of the servos closer to the centre. And on a bird like that it's not going any difference.
Good luck with the build

[gr4ndp4]

After further tour of wing pictures on google I see some have their horns closer to the end and very few towards the centre of the elevon, decided to go with the flow and used 11cm. The other advantage is the servo leads are long enough to reach the Rx position without an extension - the fewer connectors the better.

[iPeel]

it looks cooler too.  ;)

If you're worried about elevon flex then use some 9.5mm x 50mm T/E stock. I can give you a link if you need it. That said I haven't noticed any performance difference between the elevons supplied and T/E stock.

[nowler]

kit elevons are more than stiff enough if laminated.  i've flown mine at over 100mph and the elevons are just find.

[ThunderstruK]

Started painting the wings of my venturi. On this occasion I thought I'd let my other half have some fun and do it.

Granted it won't be the easiest thing to see due to te colour scheme, but that shouldn't matter too much. If nothing else it's very different to anything else I have!

[Brucey]

Cool, hard to do?

[ThunderstruK]

Well it's not hard but its time consuming. Hopefully will be worth it in the end.