Folland Gnat T1

Quorneng wrote "3. Do nothing, maintain true scale appearance and live with the limited authority."
What would be the effect if you used a high rate with a fair amount of expo ?

I think Eric's right, maybe time to bite the bullet and start again...

My only experience of an all flying tail is with my Hawker P1121 (The Super Hunter?) that has similar geometry but a bit bigger. Its all flying tail is hugely powerful. After a couple of 'almost impossible to control flights' I had to alter the linkage geometry to reduce the travel to give only +/-15 degrees but with so little movement it took several more goes before the 'neutral' position was anything like right.

Given the simplicity of just making full tailplane span elevators I will do this first. The travel will be at least +40/-25 but if it proves to be too 'soggy' then a new tail plane it is.

Just a thought but was not the benefit of all flying tail surfaces more to do with huge CofP movements with normal wing sections when close to the speed of sound rather than a lack of elevator authority at low speeds?
Trans sonic is not likely to be an issue with this.

Okay, thanks for that. So question. Are longer but not so wide surfaces more efficient for ailerons & elevators than the barn door type?

crash
I believe the aerodynamics suggest for a given area and angle of deflection long and narrow is more efficient (force generated for the drag created) but it does not give the greatest force. That comes at some ratio of the fixed to movable chords.

I understand very narrow strip surfaces on a relatively wide fixed one can have the highest force to drag coefficient but obviously are difficult to make rigid enough not to twist.
Its all a compromise.

Not much to show as the formers on top of the wing needed very careful fitting and adjustment to ensure a smooth cockpit canopy profile.

About to fit the ESC. This will enable the rx to be finally positioned and thus the servo wires to be terminated at a suitable length.

Not a lot done today but it now has full span elevators.

I actually made a mistake mounting the elevator servos - they are symmetrical. Doh! Two channel elevators are not an option on a stab rx so I have a servo reverser on order from Banggood which may take some time too arrive.

Charged up the chosen 1500 mAh 3s and conducted a thrust test nose down on the kitchen scales. It showed 11.7 oz.
Not too bad given it gave 12 oz with the slightly shorter 'prototype' duct that also had its inlets in 'free air' rather than along side the nose as in the working duct.
The only issue was the ESC got rather hot. I shall have to re measure the amps just in case it is too close to the ESC's notional 30A limit.

Klippy
If I remove an elevator servo now I have full span ailerons it would actually be easier to simply rotate the servo 180 degrees so it was oriented in the same plane as the other one. The servo would fit back into the same cutout just the slot for the servo arm would have to be made good and it is after all on the underside.

With so little wall space left to store it I decided to make the wing removable which actually proved quite simple with a nylon bolt in each corner and small printed fittings.

Of course it took nearly all to do, but then I am not going anywhere, and it works well for just a few gms of weight.
The fuselage/canopy section over the wing can now be completed which will also add a bit of stiffness to the wing centre section between the bolts.
The short removable bit of the canopy will act as the battery hatch and also give access to the rx and the ESC - just in case it needs to be replaced.

The last decision is from which plane to 'steal' a stab rx!

Eric
Yes the V-2 is the most likely subject as a donor. I cant remember if it was in anyway 'special' to handle a vertical take off but it certainly stabilised it in normal flight.

With the fuselage section built over the wing the structure is substantially complete.

In this state, less battery and rx, it weighs 9.98 oz (283 g) so paint and 'final bits' will add a bit more.

Went up in the roof to extract the 'stab' rx from the retired V-2 only to find it isn't.
It is a conventional 6 channel 2.4 with a separate gyro. I remember now I chose it because it had a switchable 'attitude hold' feature which would be useful for the vertical take off although I never got it to work properly.
It actually proved much safer just to leave it in normal 'stab' mode and rely of the motor torque to rotate the V-2 slowly so the average direction was straight up.
As everything in the V-2 was built in I can't be bothered to unravel what does what so the 'steal' will have to come from something else, probably the Depron Ballerina as the rx is fairly easy to extract and I know it works well and an online manual is available.