RE: DerJet DH Vampire build thread-
 

J.F

Yep, that's the plan, just completing the turbine install (2 hours start to finish!) Working out battery positions for balance and were good to go.

JP. Really good company to deal with. I'm very happy we took the agency. That last Vampire kit that arrived, the customer was so happy that the day it arrived he ordered a second kit!

Dave

RE: DerJet DH Vampire build thread-
 

hi dave ..you have PM

RE: DerJet DH Vampire build thread-
 

Many thx to all dave, eric, and derjet company for help me and to produce a very good flyer with scale flight attitude.
i use 1/3 of trust to fly in scale mode...
then i have only 3 successful flight and i need to find the best setup landing for our runway

90 mt tarmac and 120 grass = total 210 mt

ps : sorry for my bad english[:o][:o]

RE: DerJet DH Vampire build thread-
 

Turbine install. In a stupid moment I forgot to install the filter, hence the slightly odd position. Just the tank filler position to decide, batteries and ballast. I then need to mount leg doors and sort cockpit set up.
Then it's out with the pencil and crayons!!

Dave

RE: DerJet DH Vampire build thread-
 

Dave,

I think that the new Jetcat P100RX will be perfect for this plane !
It will be a lighter turbine that the P80SE....Almost 300g saved for a thrust of 10kg announced....

But the P80SE is a good compromize too ;)

Again, good luck for the maiden flight :-)

jean-Philippe

RE: DerJet DH Vampire build thread-
 

Sorry..it seems to be a P120SX ? [sm=confused_smile.gif]

Jean-Philippe

RE: DerJet DH Vampire build thread-
 

JP

Yes, the P-100Rx was my first choice...But to fly scale, I feel you need more power. The scale speed of the 1/5th scale vampire is around 100mph (less really) so without the energy you need lots of thrust to power through a scale flight pattern. This aeroplane would fly fine on the P-70, but not at scale speeds. Most everyone flies too fast with scale models...this is not an Ultra Flash or Bandit.
The plan was to fit a P100RX later this year, then this P120SX will be free for my DerJet Cougar. We will see.
I have just checked the balance roughly and 1kg brings the balance very close. I have only checked it with a bag of Couscous from the kitchen cupboard!
Future Vampires should need less weight as I asked DerJet to reduce the tailplane weight over mine, which is quite heavy.

Dave

RE: DerJet DH Vampire build thread-
 

i start to create the italian stencils and decals for vampire

http://a7.sphotos.ak.fbcdn.net/hphot..._4258068_n.jpg

RE: DerJet DH Vampire build thread-
 

Last few things. My method of joining wires.
Fill valve position .

Dw

RE: DerJet DH Vampire build thread-
 

nice work Dave....;)
when the first flight?;)

RE: DerJet DH Vampire build thread-
 

Christian

Maybe tomorrow, if I get the last jobs done. I fitted the leg doors 1.00am this morning, I need to balance, add something important I forgot! and start fully checking systems. I have several other jets to finish prep on before tomorrows Jet Meeting...and work!

Dave

RE: DerJet DH Vampire build thread-
 

ok...remember to post the video and some photo!!!

RE: DerJet DH Vampire build thread-
 

Ciao Chris, grande lavoro!! siete il meglio!! Vin

RE: DerJet DH Vampire build thread-
 

Ciaoooooooooooo VINC..... grazie ...come stai? tutto ok?

RE: DerJet DH Vampire build thread-
 

tutto il buon qui grazie!! Vin...

RE: DerJet DH Vampire build thread-
 

Nothing I like more than a late finish:eek: Thanks mainly to my friends;)

So, ran the turbine at the office yesterday, perfect as expected with a P-120SX.
Fuel levels shown after the run. Fitted the PB sensor switch unit in the engine bay.
Been working on the cockpit fit tonight, still not 100% happy, but a second set of hooks have improved it. Just gluing in 1020 grams of lead in the nose then bed!

DW

RE: DerJet DH Vampire build thread-
 

Very clean installation!!!!!;););)

i'm starting to create ITALIAN decals and all stencils in italian language like original aircraft

RE: DerJet DH Vampire build thread-
 

Christian.

Like most new models, as I finished the install, there were a couple of things I would change next time! Thank you anyway.

So, the Vampire has flown!
Last night...this morning! I found a small problem, all the testing I did on the gear, I was pumping to around 60-70PSI which functions the gear fine. I knew that for flight and with the doors more pressure would be needed. So last night I started using 95-110psi to fully pressure test things. At these pressures, occasionally one leg would stick up. The extra pressure meant the leg door was hard against the shut in the wing and like this the leg would not release. A light press "in" would allow the cylinder to release and the leg would come down. So..I added 0.4mm ply packers under the leg door mount and the operation seemed reliable...but I had a thing in the back of my mind.
Balance was achieved with 1120 grams lead in the nose. I balanced it on the wood former, UAT full, some fuel in the main tanks.
My movements and expo suited my flying needs perfect, so will assemble and measure/note in a while.
Take-off roll was 100m on tarmac without flap ( I will now use some flap as the ground speed was higher than I expected on rotation ) Rock solid feel, few peeps of aileron trim and it was perfect. Rolls are axial with my aileron set up ( will measure) and as expected power with the P-120SX meant most of the flight was with the throttle at 1/3-1/2 stick position. I did one full power loop which was 600' (200m) dia and you can throttle back at 3 oclock. We had a 8 knot cross wind today and again as expected the Vampire fish-tails slightly with the big pod and small boom/fins. Nothing nasty though. Flap test showed no pitch with no down elevator on TO flap, and 3% down on landing (I like a slight nose down sit on full flap)
Flight time was set for 9 minutes, but I expect 11-12 with my power settings. So at 9 minutes I hit the gear switch, the sticky main leg had stuck again [:@] Great! Several fast rolls, and rebound rolls were tried to release the leg but nope [:o]
So I cleaned up and made a grass landing. Obviously I touched the leg and it popped down [>:] Luckily no damage and I have the vampire back in the workshop to re work the gear door (like I should have before I flew her! Lesson 1!!)

Hope to fly again on Sunday

Dave

RE: DerJet DH Vampire build thread-
 

Looks good Dave! Hope you get the gear sorted soon. Bring it to MF please... :)

RE: DerJet DH Vampire build thread-
 

congratulations Dave ...........looks supberb in the air..

the silly little things catch most of us,you have had too many late nights http://www.rcuniverse.com/forum/js/f...ular_smile.gif

any idea of all up weight?

Robert

RE: DerJet DH Vampire build thread-
 

Pat
Sorting now...yes MF for sure.

Robert
Not to me!
Not weighed, will do, but flies light!

Controls are Aileron 15mm each way 35% expo and Elevator each way 22mm and 40% expo.

Dave

RE: DerJet DH Vampire build thread-
 

Congratulations Dave on your flight.
Work is still coming along on Eric's plane.
I got the inside painted today and started to figure out how we are going to run all the wiring and plumbing.
Below are a few Photos.

RE: DerJet DH Vampire build thread-
 

Bill

Looking good, I wish I had painted inside my engine area, looks so much neater

Sorted gear issue, packed the door off a fraction...but also found that leg's tyre was just touching the top skin, so packed the unit a fraction.

Regards

Dave

RE: DerJet DH Vampire build thread-
 

Had a great day flying the Vampire, really windy and gusty/thermal wind at that, but it copes well. My only thought after today is to add a gyro the the rudders, it needs it as I expected, with such a big pod and small booms/fins. I'll add a JR 420T soon.
Only made two flights as the conditions didn't make it "fun", though the two flights showed me what a good design DerJet have. Mine is complete with whistle, just like Goblin exhibits!
Gear is perfect now after packing the main unit 1/16". Everything on the model works perfectly, with the throttled back P-120SX I was flying 12 minutes with LOADS of fuel left!! It is over powered, 20-25lb would be perfect. Airbrakes just add drag, I used take-off flap on both flights today and it floats off perfectly, at TO flap still no elevator compensation and landing flap 3% down. It retains energy well, loads going down hill, I used the airbrakes on the back side of BIG loops to control speed. Really really like it!
My son William was cameraman today and I told him to take lots of shots...he took hundreds! These are some

Dw

RE: DerJet DH Vampire build thread-
 

Opps that lot are out of order! More