An EDF Concorde - in Depron.

Thats BIG, looks fantastic i do admire your building and creative skills, super job

that looks fantastic simon.

makes me want to dig out my plans now that i had blown up. he he he

WOW Simon how its grown that photo shows how big it is,didnt realise.its fantastic.

Its sheer length is getting me worried about elevator power from the modest elevons.
I fear that with its limited thrust the CofG will have to be "spot on" to fly but I have no way of finding out where that might be.
The normal solution is to set is conservatively forward to start with and then move it back but with such modest elevators if I cant keep the nose up.......
So I have set about adding scale inboard elevators. These can be joined and driven from a single servo in the fuselage.
My intention is to keep the elevons as well so it will have double the elevator power although if it has to be used the extra drag will probably mean no more than an extended glide even at full power but hopefully it would allow enough flights to get the CofG something like right.
It time I hope the elevators will become just adjustable reflex surfaces with the intriguing possibility they could be mixed with the flap switch to hold the nose up for landing.

Two steps forward, one step back!

Watching this thread with great interest Q

Garry

ah the joys of scale model building.
but knowing you it will fly like a dream sir.

To get sufficient access one fuselage former is temporarily removed.
The inboard elevators fitted and linked with a substantial thin wall glass fibre tube.

A Depron pad has been built up in the lower fuselage to mount the elevator servo.

It occurred to me that with all the EDFs, ESCs and servos right at the back it would have been possible to provide the power and earth to each directly from an ESC. It would then only be necessary to bring a single power and earth wire forward along with the 4 signal wires to the radio.
It would mean the three servos and radio would each obtain power from its own BEC!
Maybe next time!

You do make me envious Q. This thread is brilliant

Garry

Andy Watson who pops in from time to time built a Concorde in Balsa and had problems taking off.I believe yours will be substantially lighter .How have you worked out the motors youll need.?

Well actually it was all done back to front.
A 40mm EDF in a scale nacelle gave me the overall size of the plane. A static test gave me thrust so 4x40mm gives me the total (1 lb).
It is now an exercise to see if I can build it light enough to fly with that.
The EDFs are only rated for 2s (I 'fried' one on a 3s) so the weight is the only thing left for me to control.
Take off is no problem as it will be hand launched and belly land.
Of course if I had not stuck rigidly to scale I could have used just two 55mm EDFs, had a higher thrust and used less power as well!

It does not look like much progress but it commits rather a lot!
The LH twin fan unit goes in.

RH to follow.
Although the solid wire conductors can be easily bent they are obviously not 'flexible' in the conventional sense so I will take a bit of ingenuity to connect them together and to the even thicker conductors that will lead forward to the battery. (No picture as it is not finalised yet! )
Due to its length there will 3 extra capacitors spaced out along the Battery to ESC conductor.
It will be interesting to see what the battery to ESC voltage drop actually is when running at the full 52A power.

fantastic build sir.

cant wait to see how you sort the long battery cables out.

This gets more and more fascinating Q, I so hope the eventual maiden is successful

Garry

Eric
I am using varnished solid copper (magnet wire) to save weight. On the average RC wire the silicon weighs nearly as much as the copper.
There will off course be a short length of the proper flexible stuff for the Deans battery connector.