An EDF Concorde - in Depron.

.... Just looking so exciting.. .. I used one of those Orange 3 x axis gyros on my FPV platform.... didn't like it much, seemed a bit agricultural to me. I swapped it for a slightly more expensive Eagle Tree 3 x axis stabiliser which is a lot smoother operation.
Cpl. J.

I decided the only way I stand a chance of establishing a 'safe' CofG is to build a simple 'profile' chuck glider.

20" span it is small and light enough to use a simple plank wing in 6mm Depron and a cruciform fuselage also in 6mm.
The fin is 3mm Depron and the engine nacelles are 2mm Depron hollow boxes.

With 0,15oz ballast to give a 50% CofG it weighs just a fraction under 2oz.

Of course it is blowing half a gale at the moment.

Now I do have two 35mm EDFs which would just about fit.............. NO! NO! ........ Don't even contemplate it!

Back to the proper Concorde. The next step is to move the elevator servo right to the front using a long lightweight snake.

Securely mounted it passes through no less than 16 formers and is fixed to 2 more.
The servo (5g) is mounted right up against the removable nose section.

I had intended to use the Orange 3Axis Rx but it appears to conflict with the elevon mixer unit which causes the servos to judder alarmingly.
I would use its built in Delta elevon mixing facility but it does not seem to work! Query posted on Hobby King site!
So in this test video is it using a second hand 35mHz GWS Rx bought for peanuts of Ebay!

I suppose it will get finished one day.

Eric
I was 'stirring' the stick with full deflection so with both an elevator and elevons you get that interesting 'wave' effect across the control surfaces.

I don't know if such an arrangement is sound but with such a long narrow delta I suspect its elevator authority that will be limited rather than roll.

Eric
It was indeed your Concorde post on the RCME site along time ago that suggested to me that pitch rather than roll that might be an issue hence the rather unusual elevator plus elevon configuration.
Both my other deltas (Skyray and FD2) have a higher aspect ratio so the roll and pitch response from just elevons feels comparable.

With the arrival of the remaining Mystery ESCs the installation can start -again!
The two bare ESC with solid copper conductors soldered directly to the circuit board.

The wires to the EDFs are threaded through the wing.

Note the little Depron blocks to ensure the bare soldered connections cannot touch.
The top skin replaced.

The RH pair have been run at full power with the full length wires in place and shows 18A at 7.25V (135W) using my 'bench test' battery. The bigger 3000mAh Nanotech 35C flight battery should maintain a higher voltage.
Now just have to do the same thing on the other side.

With the other side completed the first run of all four of the ESCs in their new location.

Each ESC has its own feed from the battery.
The watt meter showed 31A at 6.7V giving 218W.
Given it is a 3000mAh Turnigy Nanotech 25-50C it is a bit disappointing that it only managed 6.7V at 31A (which is only just over 10C !) but it was not fully charged.
I had rather hoped it would hold close to 7.4V at such a mosdest current. At 7.4V the 4 EDFs should draw a total of about 40A.

Eric
Yes a 2S. These are supposed to be quite good.

50C would be 150A but based on the performance so far heaven only knows what the actual cell voltage would be!
It claims the cells are matched for internal resistance and they certainly show the same voltage to 1/100 of a volt!

Each of these fans can safely take 10A (the max is 12A) but on the 2s it is currently only about 7.6A. The question is what happens if I go to a 3S. On the bench a 3S took it up to 16A (and burnt out the motor) but in the plane I am using much longer thinner wires so there is significant voltage drop.
A 2000mAh 3S would be the same weight at the 3Ah 2S but at 40A it would drawing a full 20C so it would have only a 3 minute full power endurance.

With the ESC and EDF installed with the wires in the wing the upper surface can be made good.

Spent most of the day designing and redesigning how the battery should be installed.
Eventually setted on an 'edge on' installation.

Once the battery box is complete the majority of fuselage planking can be finished..
The section of the fuselage over the battery will be side hinged, probably with a magnetic catch.

The battery box completed.

As the skin carries all the load on the rest of the fuselage and with a large cut out over the battery the box itself has to be a load bearing structure.
The radio is the final element to go in, just ahead of the battery.

In theory atleast it will be possible to remove the radio from the front with the nose section removed.

I will have to build and fit the fin before the last of the fuselage planking goes on.

Still in the dark but I think I can now see the end of the tunnel!

With a couple of top fuselage planks added the fin can go on.

It looks a bit more 'Concorde' now.

Don't want to teach granny to suck eggs, but don't forget to use clips, or at least tape, to stick those servo leads or extension leads together. The last thing you want is for them to work loose in flight.
This is certainly an impressive project, I wish I could be there for the maiden.
Remind me where you live please Simon ?????

Pol.