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Dec 28, 2013, 09:38 PM
USA: LakeGeorge, New York
Cool

3m FPV plane.....Cool Build!



GEMINI ADVANCED LONG RANGE FPV PLANE -REVIEW- FPV OR UAV? THE ULTIMATE FPV PLATFORM! (21 min 46 sec)
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Dec 29, 2013, 12:18 AM
Registered User
Wow
It fly's nicely.
Looks smooth
Dec 29, 2013, 10:21 AM
my karma ranover my dogma
galaxiex's Avatar
Very cool!
Seems a well thought out design.
Dec 29, 2013, 02:01 PM
OpenTx University *****
Casey101's Avatar
Nice!
Dec 29, 2013, 02:12 PM
Just clumsy. Oh, forgetful too
MikeTheCrash's Avatar
Awesome build, top job!!
Dec 29, 2013, 03:23 PM
USA: LakeGeorge, New York
...at the end of the clip, he may make some for customers made
out of foam.....uuhm?
Dec 29, 2013, 10:42 PM
Registered User
Very cool plane.

I feel he could pick up some major efficiency with a single motor, and ditching the NACA foil... NACA 4412 is not a very efficient foil. At 3.5m he has more than enough wing for the weight he wants to carry. Moving to a more efficient foil could be huge. Even something off the shelf such as the RG15 would take minimal adjusting, and would improve efficiency considerably.

Very nice Idea with split flaps! Huge advantage when slowing down with a slippery airframe. The disadvantage is that you can not use them to trim your cruise speed, for instance you can slow the play down considerably, while maintaining some efficiency with normal flaps. Also if you split the aileron channels, and use a dual aileron set up you can set up crow, which is used commonly in sailplanes and pylon planes. Crow raises the TE of the ailerons to create a ton of drag, as well as reducing tip stalls, meanwhile lowering the flaps to increase lift at the center of the wing. This slows the plane nicely, as well as provides a large amount of lift for a slow touchdown. In the mean time it is programmable for in flight flap optimization.

Please, if the developer reads my comments, do not take them offensively. I am simply providing my input that may help with design if you do produce a production model!

Sincerely,
Justin

PS, the hardpoint Idea is ingenious.
Sep 13, 2014, 02:15 AM
Registered User
The Gemini Prototype has completed a near 3 hr. endurance flight , while carrying a payload(observer cam with pan tilt, and 2n'd video link). i will post the video. i think it could have carried a couple more batteries, and flown for longer, or taken the landing gear off.
looking into using the new panasonic cells for longer flight. (150%), or using a hybrid power plant running on coleman camp fuel possibly, instead of carrying so many batteries. any suggestions, anyone?
Sep 13, 2014, 02:41 AM
Registered User
I thought it would be appropriate to respond to some comments about using a thinner airfoil, for "efficiency".
what is important here to understand is the goal of the aircraft. for my purposes, i have picked endurance, and ability to carry a payload over a distance efficiently. when looking at efficiency, let's take the example of two gliders, one with a more efficient thin wing , with better lift to drag ratio, and another with a slightly less efficient foil, but a higher coefficient of lift. the glider with the thinner, foil may glide farther, but the slower glider with the thicker wing, will fly slower, and has the potential to meet the ground later, because it's going slower, so it's endurance would be greater. factor in the ability to carry more weight, and the ideal airfoil airfoil is around 12 percent thick. is the nada 4412 the best foil? probably not, but it does work well at the reynolds numbers being experienced, and it's not a critical foil. important if the structure is not perfect. the real world is so much different than a simulator.
justin has a very nice, very advanced design that he is working on, and i think in the end both designs will have strong points. one thing that the gemini won't do incredibly well would be to penetrate a very strong headwind, as airspeed in cruise flight is limited to about 70 km per hr. and power system efficiency is very low at that kind of airspeed, and throttle settings. the other issue i have is with people saying that a single engine aircraft is more efficient than a twin. that is simply not the case, in my opinion, and if studied in depth, the myth of a vortices off of prop tips does not hold up. the pressure migration that is normally experienced by a wing at the tip does not apply to props, as they are rotating, so constantly changing their relative yaw, if you will relative to the airflow. somewhat like a fwd swept wing. the net migration of pressure is zero. there is a great video on youtube about this called something like misconceptions in aerodynamics, and it's good research material.
not everything can be modeled in a computer yet. that's why nasa still uses wind tunnels. and don't get me started on those lifting body concept aircraft. anyway, Justin is well meaning, and i do think long and hard about everything he says. if you guys have not checked out his design on diydrones yet, you should . it has a lot of potential!
Sep 16, 2014, 06:22 PM
Registered User

slight correction


Quote:
Originally Posted by rclab1
It's actually 3.5 meters span
Sep 16, 2014, 06:55 PM
Registered User
Version 2 is undergoing flight testing! Plans available soon!

3.2 meter wingspan
Thicker airfoil
Does not need flaps or speed brakes
good STOL performance
can fly at 20 lbs gross weight
Fits in the trunk of a small car (Vertical stab is removable with 1 screw)
3 piece wing
designed to provide ideal layout for fpv components
big stable airframe is easy to fly
has 2 removable hatches on belly, and two on top of fuselage
ability to handle swappable payloads
simple robust construction
structure reinforced with extensive use of carbon fiber pultruded strips
uses common hobby parts
does not require advanced building experience
ideal for:
commercial applications
crop monitoring
surveying
surveillance
search and rescue missions
experimental flights such as mid air recharging of smaller aircraft
package delivery by parachute
aerial photography
air quality monitoring
disaster assessment
flight training for other unmanned systems
FPV for hobbyists
candy drop (soft candies, preferably)
long range reconnaissance
bird counting
ocean/kelp monitoring
and many other uses

let us know what you would use it for!

we will post more specs when flight testing is complete!
Sep 16, 2014, 07:04 PM
Just another FPV addicted teen
EpicRC's Avatar
The V1 looked cooler with the ribbed wing and balsa...
Sep 17, 2014, 02:14 PM
Registered User
I agree it looked better. The white is more practical in the direct sunlight, as the airframe stays cooler. and it's easier for other planes to spot in the air, whether they be full size aircraft, or other fpv models. also, the clear covering had the tendency to accumulate visible moisture inside the wing bays, and although that probably happens with other colors, on the clear you can see it, and that dozen;t look very good.
anyway, v-2 is made to be more practical, and useful for commercial applications. it's also a lot easier to fly. if you build the model, which takes about 1/4th the time of v-1, prototype, you can cover it any color you want. what do you think would look best?
Sep 17, 2014, 02:23 PM
Registered User

spec sheet


here is the spec sheet for the gemini v-2.
please excuse the error on the wing loading. other that n that, i think everything else is correct.


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