This will be my 3rd version of this classic model, but the first where I'm documenting the build. Avicraft
15. Maiden flight
Model complete, or so I thought. Last minute I changed the engine to a Jen 56 (Engine shown is an OS 46AX). Already had first flight, and she flies as well as my other 2 did.
13. Elevator & rudder connections
2 servos mounted in the fus, the elevator uses a 5mm Carbon tube, and closed loop for the rudder.
12. Aileron connections
Servo along the spar, so we are not going too far into the wing. The ball joint ensure that the geometry is always right with no binding. Note the 1/4 hard points in the ailerons.
11. Everything covered
Everything covered, and aileron servos fitted.
10. Ready for covering
Cabanes sprayed with Spectrum.
9. More Glassing
Just for good measure I glassed the inside of the nose. And the outer cabanes were given a layer of glass cloth, to add strength.
Centre section glassed.
7. Tail end / ailerons
The ailerons were assembled, initially I missed the fact that there are anti warp pieces in the pushed out pieces and had to retrieve them from the bin. Tail components were tacked together and given a sand as complete units, then hinged using the supplied Mylar.
The servo tray supplid has all the cutouts for switch / Rx and std size servos, but were too big for the servos I intend to use (HiTec HS 5245MG), so this was remade, again the supplied one was fine and would suit most builders.
Fuselage takes shape very quickly.
In contrast to the wings the fuselage components are excellent, well fitting laser cut parts. I did make some changes but these were completley un necessary.
I replaced the 3/16 F1 with 1/4, just looks more substantial, and I added 3/8 triangle to the F1 / side joint. Make sure you make a left and right side, and it self jigs together. No need to jet the building jig out.
I fitted blocks in the trailing edge of the wings to accept the hinges, just a bit more wood for them to bite on. The trailing edge was stuck on using the supplied copydex and it worked fine, so my guess is that without the beds the curve in the leading edge sheeting was just too much for the glue.
As I have said this all stemed from not having the wing beds / shells.
No photos of the front sheeting being glued on, but I used gorilla glue, spread thinly over the foam, allowed to go tacky and the sheeting applied. Worked a treat, also the expansion of the glue was minimal because it was spread thinly, and would expand to fill the melt in the cores.
You can see how thin to spread the gorilla glue as around the servo well.
I was so close to ditching the cores and having some more made, but I'm very happy with the result.
I have tried a couple of times using the supplied copydex, and I'm struggling to get the sheeting to stick.
I have waited for the glue to go tacky, and again almost dry, but because the water in the copydex is making the balsa curl the wrong way it just wont stick, and with no shells its impossible to hold the cores while say epoxy cures.
I tried several times to do this but it just douldn't work, not sure why, the copydex was used neat, allowed to dry as per advice fro the modelflying.co.uk forum.
A different method was required.
First thing is to get the servo wells cut, no measurements are given so I attached the aileron with tape, found the horn annchor point and used that for the servo position.
The wings aren't completely square, but a few wipes with a sanding block had them right.
Strangley the wings are supplied without the shells which makes fitting the balsa sheeting particularly difficult. Also looking at picture 2 you can see the wire was too hot when they were cut , not giving a sound glueing surface.>