Enlarged VMC Se5a for Indoor R/C Flying Only

A few years ago I dipped my toes in Free Flight Rubber. I chose the Se5a designed by Andrew Darby and marketted by VMC. The model was a joy to build and flew really well. I did a build blog on here somewhere
Well I thought the Se would be a great design for Flying Only at the Indoor R/C Nats, so set about enlarging the plan to 22" and redesigning the wings to accomodate ailerons.
The wing construction was altered to allow the use of laminated upper wing ribs, and my simplified spar technique. Many thanks to Mr Sephton for the inspiration on that one!
The ailerons are operated by a single central servo in the fuselage, operating pull lines, running through full span micro PTFE tubing. The pull lines are invisible polyester thread. All four ailerons are hinged so that at rest the are fully deflected upwards. The lines are pulled to centre the surfaces, relaxe the pull they go up, pull harder they go down. Really simple. The top wing ailerons are simply tethered to the bottom wings ailerons. The servo has only ever to pull with enough strength to operate one side at a time.













Still have the Undercarriage to make, so far the model weighs 46g, so on target for under 50g, but it will be tight. The model spans 22"
Cheers
Danny

Thanks for posting Septic, it looks likely to be a really worthwhile project to follow.

I've been thinking about the ailerons. When the servo pulls one side down, the other side is pulling up and therefore, helping with the effort required. In fact, with equal pull on both sides, the net force on the servo should be zero....which makes it a very elegant solution for a simplified aileron control.

Very nicely done Septic. The ailerons look neat, very impressive

I did a very similar thing with my 24" Sopwith Pup. Of course it had four ailerons all connected by one pull/pull wire connected to a servo in the fuselage.

And the nylon line ran inside the wings!

Excellent! What did you use to bias the ailerons? My plan B was elastic chord pulling them up. Servo to pull down.
Great minds think alike....

All looking great!
Mike

Scaptic
No bias. It used a complete closed loop.
From the servo out in the lower wing round the lower RH aileron, up and round the upper RH aileron, right across the upper wing, back down around both LH ailerons and back to the servo.
To allow the line to be inserted after it was covered I used flexible drinking straws as cable guides.

It worked!
I can't get a Vimeo video to work but it can be found here vimeo.com/55798546
Built for out door flying, so a bit heavy for indoor, but even so much too delicate. It has only flown once on a flat calm day but was still damaged on landing!
It has hung on the wall for 3 years, maybe one day......

The micro ptfe tube is magic, you can run it root to exit and thread after covering. No mess
Love your solution though
Cheers
Danny

The Se5a flew today, and what a lovely flying machine it is really pleased. The model came out at 60.05 g including a 1S lipo. The model still needs paint, and one aileron slave link broke, so i disconnected the other upper aileron too, and taped them level. Just using the lower ailerons wasn't great but the rudder is the primary turning force anyway.

I added a link to a video but the software hasnt displayed the url, link text or an error. To tired to faff about. Will try again tomorrow. Really had hoped Andrew would see the model.
Cheers
Danny

My Se is just about done

I may be wrong but I don't recall seeing an SE5a with exhausts quite that long!

This is the Savage skywriting SE5A that had extended exhaust pipes to get the smole clear of the aeroplane. They were all silver and one hangs in the Science Museum.
Ricky

I am lead to believe that Jack Savage was responsible for many Se5a's surviving until this day. Not sure how true but I heard that the Old warden Se and the one at Hendon may be ex Savage aircraft.







Cheers
Danny

Very nice model Danny,

Funnily enough I was at the science museum this week looking up at G-EBIB thinking it would make an attractive model ...

The Blurb with the aircraft says this was the last one that Jack had left after owning many SE5a and he gifted it to the museum in 1937