Graphite 2E by Vladimir's Models
Aircraft: Vladimir's Model Graphite 2E
The quality and craftsmanship is impeccable! Absolutely stunning!
Glider is 100% built and requires only equipment installation.
At first I did not like the color scheme but it turned-out to be quite nice looking.
Plan was to have the following specs:
- Model weight: 2.5Kg
- Battery: 4000mAh 3S
- ESC: Max power 60A
- Motor: Hacker A30-18M V2 with 6.7:1 gearbox
- Prop: Aeronaut 17x11 no yoke twist
I ended-up with:
- Model weight: 2,350 grams
By parts:
- Left wingtip: 312 grams
- Right wingtip: 313 grams
- Center wing portion: 697 grams
- Stabilizer: 53 grams
- Fuselage: 662 grams (no battery)
- GoPro3 with canopy: 88 grams
- Battery: 225 grams
MKS 65K servos fit nicely in a Graphite tail and offer plenty of room for installation.
Wing servos, I bought 2 KST DS135MG and 2 KST DS125MG.
After checking a slop on MSK servos and KST servos I got MKS DS6125 mini for ailerons and DS6125 for flaps.
Hacker B40 12S w/4.4:1 gearbox on this glider is definitely not for competition flights.
It offers good compromise on price, power and idle current which allows an hour+ flight time or solid 6 lifts to 200 meters of altitude on 3500/3S battery while providing charge to GoPro 3 camera.
Motor drains on idle 1.47A per 8.4V.
HyperSpinner 38/4/0 by Vladimir's Model. It allows prop to fold much closer to the fuselage.
I created custom molds for all servos to create exact servo frames for all servos.
To preserve servos I made replicas out of silicone to make carbon-fiber servo frames.
This is a test epoxy replica of MKS DS65K servo.
Servo frames glued-in the tail section. Total frames weight for both 3.5 grams.
Servos are easily removable.
Finished tail section with wiring and controls done.
Wiring is covered, connectors are covered above the rudder servo to prevent it from interfering with servo arms movement.
Custom made carbon-fiber servo frames. Compared to ready-made Chinese servo frames my frames have zero-slope in third bearing while ready-made frames have huge slope.
Anchors for mounting 4-40 screws were molded-in.
My frames altogether lighter than Chinese ones and offer a bigger gripping surface for epoxy.
Servo silicone (Rebound 40 from http://www.Smooth-On.com) mock-up used to align frame in the wing.
Silicone is completely neutral to any epoxy or fiberglass resin so can be safely removed when epoxy is set and it leaves nice servo impression.
Wing servo installed and screwed-in. This is just check-up for proper alignment and before gluing third servo bearing.
MKS servo frame with bearing installed and aligned.
To remove servo it takes removing two screws and sliding it out of the bearing.
The whole setup is quite tight enough but works nice and easy.
Since I am using power hungry servos I elected to use one ESC for the motor (no BEC) and separate 5A ESC for servos. Optima receiver feeds directly from LiPo battery providing onboard voltage telemetry.
Motor ESC Proton-40A-Opto - means no BEC. It came with programming card, so it's quite easy to program.
Motor averages 25A, so this ESC is never hot. Graphite provides very good fuselage ventilation with two inlets on the top and one through the prop.
While trying to figure-out how to install GoPro 3 on a glider I came up with solution by making a new cockpit cover.
After mishap of running out of battery power in-flight I have built a custom USB power cord for my GoPro 3.
It feeds off the receiver's servo 5V power.
The only trick is to hook-up power cord after turning-on the camera. Otherwise power spike may (or may not) hung the camera. If camera huns - battery removal needed to bring camera back to life - known bug in GoPro 3.
32Gb SanDisk Extreme card is plenty for more than an hour of filming at 1080p x 60 Fps.
I had a bad luck with SunDisk Ultra cads - not fast enough writing at given settings and camera just stops recording.
Maiden flight video:
https://www.youtube.com/watch?v=3lqh_AiAASU
In short - stunning ship!
At the beginning it was trimmed nose-up a lot.
Power was right what I expected - not a space ship but has enough power. All power components were not even warm at the end of the flight.
Controls are very very responsive and thermaling flaps settings help center thermal very easy and fast (yes, I caught a thermal on a first flight).
Butterfly is very effective (I mean very-very effective) but I have to work-out the correct elevator position for it (apparently 35% down was not enough).
I did not try everything on a first 10 minutes flight but I fell in-love with this ship. It is responsive, forgiving, fast, great soarer with big speed range and very small turn radius while thermaling.
Money well spent!
Some Aurora 9 settings:
Speed: Ailerons - 0.4, Flaps - 0.6 - creates smooth control and greater soaring aerodynamics.
Posted by: Mark on: Monday, May 5, 2014 at 11:11 PM (23:11)
Mark is a member of Henryville RC Field club
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