Completed model ready for maiden flight. A few vinyl graphics set the Algebra off nicely.
16. Aileron / Flap typical assembly
Servos screwed in, and conncted to the control surface. The heatshrink is to finish it off nicely, there is no way for the linkage to come undone.
Servo covers are simply a sheet of 1/6 sanded so it's flush and a vinyl cut adhesive sticker to hold it in place.
15. Wing servos fitting - typical arrangement
Servo wells painted with some left over epoxy I had from the canopy, I didn't mix it especially. It looks like the servos are screwed into balsa, but its a balsa facing on top of a beech bearer. The intention was to prevent the hardwood splitting.
Servo was soldered to the extension lead, and the wire tucked up inside the well. I dont like to cut anything off the servo wires if I can help it.
14. Rudder / elevator servo fitting
Homemade grommets from silicon fuel tubing used to mount the servos. Receiver mounted in a 3D printed Rx holder from RC3DPrint
13. Everything covered / painted
Everything covered in white film. Fuselage painted from a rattle can, took some time to fill all the small holes and chips. The canopy was glassed with a home made catch from piano wire and some small bore tube that fitted.
12. First time together
Model together for the first time. Everything seems to fit OK. The all moving tailplane won't be connected until the model is complete, and I can accurately measure the incidence.
11. Wing to Fuselage
Transfering the spar holes from their position in the wing to the fuselage. When I made the wing facings I also made a extra one with the same hole centres. I was then able to make a removable copy that matched the wing section and the holes.
This blank was laid over the fuselage acurately to spot through and tranfer the spar / wire routing holes onto the fusalege. Simples!
10. Tailplane details
The all moving tail is bushed with some top hats I had lying around, to be honest I have no idea where they came from, but they stiffen up the tail quite nicely.
You can just make out a rather large void in the fuselage moulding on the fin, this is typical of what I've had to content with.
Rudder outline pre sanding.
9. Wing control surfaces
The control surfces were cut out at actual size, this still left the facings to cater for, to maintain the shape of the airfoil, 6mm (1/4") was taken off each edge. This was easily done with a balsa stripper set to the required depth. These were faced with 6mm balsa and sanded to maintain the airfoil shape.
Just a couple of pic showing the spar details before a 1/16 ply end was added.
The wing along with the mainspar assembly were assembled along with the correct dihedral, and glued with expanding Gorilla glue. This glue is just great for foam, as it expands to fit and really gets into the foam for a secure joint. Wires for the aileron servos were also run as the spar went in.
What you can't see is a digital level to match the dihedral on each side.
When the mainspar was dry, I added the 2 sub spars using the same method, assembling and securing in position whilst the glue dried.
The final pic above shows the flap servo box, lined with 1/16 balsa, and the spars, rough sanded.
I started with a 1/16 slot, and a vertically oversized ply web spar. I set this up on a flat surface at the correct dihedral. With the spar fitted I marked the top of the wing skin.
I was then able to try the main spar for fit and position, in a ply / spar / ply mainspar sub assembly. With the spar assembly I then cut out the wing cores to suit.
(Dihedral was a best guess. Its 2.4m span with 4 servos so I didn't want a ton of dihedral and have an over sensitive rudder, so opted for 50mm under each tip.)
5. Wings - deciding what to do.
All I have is a general arrangement of a built up wing, so its a case of trying the bits for fit and position.
I have a 12mm main spar and a 4mm sub spar to fit, and initially (as per photos) air brakes.
It was decided sunsequently to do away with the airbrakes, and go with flaps and a 4 servo wing instead
4. Fuselage reset
First job is a fuselage reset, to get back to a starting point. So filler and sanding and fettling.
There is no glassfibre canopy so one was made from balsa block - shaped and snanded to siut, then a generous application of filler to make the edged clean.
Plan is to finish with a couple of coats of glass cloth.
From the CAD file I was able to determine the area of the new wing, and using the original sketch I was able to work out that the ratio between the original wings and tail areas was about 8.5:1.
So using this the tailplane area was calculatied accordingly. Because the tailplane is fully moving and can be removed easily, if its wrong I can easily make more until the model feels right if needed.
Holes were drilled into the tailplane halfs and joining tubes epoxyed in one length, and cut once the epoxy had cured. Then faced off with 1/16 ply.
Wings will be approx 2.4m (The max that could be reasonably posted - 2 X 1.2) with ailerons as far outboard as I can get with HobbyKing electical spoilers somewhere near the spars.
I sketched out the wing using DevWing (I now use WingHelper but I'm still learning how it works so went back to DevWing in this instance) Why change - well thats another story eh Stefan ;-).
Construction is foam / veneer with glass cloth along the trailing edge to stifffen it up. This works really well.
1. Getting started
I picked up a partially built Algebra, with glass fuselage and foam wings. To be honest the wings were scrap, but was happy to get an original fuselage.
However on closer inspection I've seen fungal nails with a better finish, and some work had already started with cutouts for the tail and the main wing spars (in the wrong place).
So the plan was to refresh the fuselage - fill any blemishes and get a new pair of foam wings.