Announcing the Raptor 140, the next airplane in the MyGeekShow fleet. Its a major improvement on the very successful Raptor airframe, slightly larger than the current Raptor (140cm wingspan vs 120cm), with a ton of improvements. What do you think? Am I missing anything?
Improvements over original Raptor:
Four times the battery capacity (2.2Ah to 8.8Ah)
Two times the motor power output (300W to 600W)
Better servos (9g cheap analog to 11g digital)
Better air flow (exposed to embedded electronics with canopy)
Better water proofing (plastic wrapped to embedded and sealed equipment)
Folding prop (8x4 fixed plastic to 10x6 folding carbon fiber)
Add current sensor (provides live, in flight Volts and Amp draw)
Seperate GPS & Compass (instead of mounted to APM, improves sensor clarity)
Adjustable camera angle (instead of fixed)
Add FPV Tx (to send live video feed to ground)
Add Airspeed Sensor (improved navigation, allows efficiency testing)
Improved Crash Damage Reduction (Batteries secured safely)
Larger and additional Carbon Fiber spars
And more...
Estimated performance:
Weight: 1200g to 1500g
Flight Time: 30min - 45min
Stall Speed: 25kph
Cruise Speed: 60kph
Max Speed: 120kph
Radio Range: 1.5km
The equipment that will go on it:
Autopilot: APM2 (no longer sold, visit http://store.3drobotics.com/products/apm-2-5-kit)
FPV/Onboard Camera: http://www.foxtechfpv.com/horyzonhd-full-hd-1080p-fpv-camera-v3-p-877.html
Radio Tx: ParkeFlyer Turnigy 9x Tx: http://parkeflyer.com/
Reciever: 6ch FlySky http://www.hobbypartz.com/79p-r6b-receiver.html
Telemtry: 915mhz 100mW 3DR http://store.3drobotics.com/products/3dr-radio-telemetry-kit-915-mhz
FPV: 5.8ghz 600mW http://www.foxtechfpv.com/58g-600mw-32ch-vtxrx-p-1118.html
Battery: 4.4Ah 30C Sky Lipo: http://www.hobbypartz.com/77p-sl4400-3s1p-30c-3333.html
ESC: 60A Brushless http://www.hobbypartz.com/proton60aair.html
Motor: 3542 1450kv brushless http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=38700
Prop: 10x6 Carbon Fiber Folding http://www.hobby-lobby.com/10x6_carbon_fiber_cam_blade_797_prd1.htm
Servos: 11g digital http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=42620
UBEC (for FPV camera): 3A http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=4319
Airspeed Sensor: http://store.3drobotics.com/products/airspeed-kit-with-mpxv7002dp
Learn More:
Raptor Details: http://www.mygeekshow.com/theairplanes/Raptor.html
USA Trip Details: http://www.mygeekshow.com/usatrip/
Follow the Show:
Website: http://www.mygeekshow.com
Facebook: http://www.facebook.com/MyGeekShow
Twitter: http://twitter.com/mygeekshow
Google+:http://plus.google.com/116950154481685699344
Skype: MyGeekShow
UStream: http://www.ustream.tv/channel/mygeekshow
Filmed, Edited, Produced and Published by Trent in Arkansas, USA
Comments
It`s ok, we are here to help
sorry jernej, not my intention be rude ...
my english is poor and some time i not choose correct words to express what i want.
@ Dwgsparky, you are right, and thanks for explaining rather then being rude.
@Jonathan Arad, I was more focusing on a batteries, yes I guess 2400W would be an overkill. I was looking for best price per performance battery.
@Jernej Plešnar
Why would he need 2400W on a 1500g airplane? Also it weighs 454 grams!! that's 30% of the planned AUW.
Power output is not as simple as it seems! you are not comparing like with like.
if you take a 3S /4000ma it is half the weight and size of a 6S/4000ma but it has the same mah capacity
Go back to ohms law.... power = V x I so if your nice wing needs 200watts to flywell then it will still need the same 200w of power whatever size battery you have unless you change the mass of the plane and battery.
so your 3S / 4000ma will have to provide 200w / 11.2v =17amps =200watts
your 6S / 2000ma (same wieght approx as the 3S 4000ma ) will have still have to provide 200w / 22.4v=8.9amps =200watts so the batterys will go flat after the same time.
There are 2 other points to consider. The 6S will give a higher RPM on the same motor so the same propeller could (in theory) produce much more thrust, BUT that will require much more amps but now the losses start to mount up and work against you.
now the good stuff.
Our ESC and motor together with the wiring ,connectors and batteries ALL have resistance. resistance produces heat and wasted power.
so if power (loss) = I x I x R and we figure that the combined resistance =0.2ohms (example only)
then we get 3S @ 17amps 17 x 17 x 0.2 = 57watts lost energy
your 6S @ 8.9amps gives 8.9 x 8.9 x 0.2 = 15watts lost energy
So by using the 6S You reduce your losses from 28% ( of 200watts ) to 7.5% (of 200watts) so you will have a corresponding increase in run time of about 20% assuming the plane is flown at the same weight and speed.
dont forget that you also need a higher voltage system for recharging after the flight.
One final point., when thing go wrong with a 3S system you create a lot of smoke and heat! with a 6S system the theoretical power is much greater and the chance of fire is seriously increased.
Dwg
First, power output depends on prop too. Do you always push your car to the end? Hobbyking graph says the motor is most efficient at less then 80% throttle. I am just suggesting, you don`t have to insult people ...I bet 15000 mAh on 4s cost a fortune, eduardo ..Sory Trent if I am overreaction but just trying to help here.
some crazy people here!
my 2.6m wing fly at 32m/s using 15000mh/4s and an G32 motor without any problem.
In calm day it fly 1hour and 20 minutes with 500gr payload
It can carry 20amp battery without problem or even more if necessary.
2400w motor is not too much for a 1.4m wing ???
I agree with Gerard Toonstra for tapered elevons, as you get more control. And about power setting, maybe even 8s for same weight, if you calculate 29.6V/22.2V=1.3 for 4000mah 8s(29.6V) which is a third compared to 5000mah 6s as a fifth more capacity for a third less voltage. So 8S 4000mah is more worth paying for http://hobbyking.com/hobbyking/store/__21365__ZIPPY_Compact_4000mAh...
and motor http://hobbyking.com/hobbyking/store/__22036__NTM_Prop_Drive_50_60_... that gives awesome 2400W. It`s maybe 30-40 bucks more expensive, but the performance must be great. You can still go at 30% power at 800W, but I am sure you could easily get 120 km/h+.
Trent,
Important characteristics of servos are the currents that run through it, its torque and its speed. I was suggesting to measure the currents, not replace them necessarily. 1.8kg/cm is used on some docile gliders and they should do the job ok. As soon as you go over 100km/h or in excessive manoeuvers pulling lots of G's you may want to get a bit more torque. If the control surfaces is under high load, then the servo may also stall or it may not be able to change the surface altogether, resulting in failure.
The prop stop is necessary on both sides of the prop by the way. Besides A, you may also have a situation like B where the left prop half is thrown back into position. If the start is a bit slow, this momentum can overshoot and hit the foam in the back, either destroying the prop half or the motor mount. If the prop half is gone, you'll run very unbalanced and it's likely the entire motor mount comes down. A stop in the back really prevents that from happening.
You're also using the foam on the wing itself as a control surface. It may be a good idea to use balsa elevons lined with 3mil instead. They're certainly stronger and won't flex as much. You can then also make them tapered on the outside to increases the response and smaller on the inside, decreasing overall drag. You simply tape them to the airframe with postage tape.
If the distance from the servo to the control surface is a bit long and you do have a bit more speed, then the control rod can bend slightly over time. At some point it will double up. You can add a little carbon tube to prevent that from happening.
FYI. Prop stopper provided by prop manufacture.
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