SFS 31 Milan

[Noël Rumers]

Hi Cliff,
To which scale will the the Blanik/Vivat be? I look forward to see the design!
I have been working on mine last year November too. It had to be in the air somewhere...
Years ago I did cut the polyurethane foam blocks to size... never got to the point to start gluing them together due to other projects.
Last year I had to reorganize the space I have so, this was the time to sort things out. I also did find mistakes in the shape that had to be solved.
All blocks are at the highest point painted black so I can sand to that line to get the right shape in the end.
The scale of mine is 1/2.75. The fuselage shall be in two parts as well as each wing. The hinges for the elevator are milled by CNC to fold up like the real plane, both the Blanik and the Vivat. Will be for next year...
I have lots of detailed info on both planes as well. We had two Vivats in Belgium flying. One had be written off due to a forced landing on a lake in the south of Belgium. It had been salvaged from a depth of 10 m. I have the main landing wheel and e few other part of it at home. The fuselage welded construction, not often seen from a plane, is fully measured as well as other things.
See the drawings as well…
Noël

[Noël Rumers]

...the Milan again...
The landing gear had a weak spot. The bold that was used to arrange for the pulling in and holding it into place both in and out was the problem.
After some study of the system A new part had to be made. This already was OK for Milan 1 but not on the second one. So back to the cellar to make the part.
The gap between both sides of the brass retracting arm was 30 mm. With the guiding block being only 10 mm this was asking for trouble with a harder landing. So the new block supports the bold over the full width of the gap. All is strong now and a nice job done again.
Noël

[Noël Rumers]

First I did want to reinforce the firewall to the sides of the fuselage a bit more. Had to do this also on Milan 1. Glass fibre cloth and epoxy did the job with some thinkened epoxy to fill the corners and round the sharp edges a bit. The fuselage inside was painted and the fuselage sides at the point where the radio and other stuff was installed had to be closed. Most of the time the fuselage is always too small to work with both hand in... so I left these parts open to the very end.
A template was made and a reinforcement spar installed to give the 0.6 mm ply some more stable setting.
Noël

[Cliff Evans]

The Vivat is 1/3 scale will email the plans for you to look at.

[Noël Rumers]

OK Cliff,
I look forward to see them. Maybe better a bit smaller, but the engine I had in mind was the ZG62. Now we have other options too. Also electric is better now than in the old days, when I was planning the Vivat.
Still, bigger plane, fly better!

Noël

[Noël Rumers]

...and the Blanik...
This one was owned by a good friend. He was serviced and after it got back the wing tips were changed.
A storry with a strom and things on the road... But still a one off! and easier to build I recon.
See also the wings TE. I was able to measure the wing. At mid wing, the start of the aileron, the wing TE was 40 mm up from the straight line.
The LE however was straight!
Wing at rood 4°, at mid wing 1.5° and at the tip 1°. Wing rood to mid wing, is the Naca 63²A-615 and at the tip the Naca 63²A-612. Being 15% and 12% thick.
Noël

[Noël Rumers]

...right, here we are again with the finishing of the fuselage of Milan 2.
The wing joiner is a 25 mm glass fiber rod that runs from wing to wing for about 200 mm in each wing. Because the fuselage is not flat where the wing fits the fuselage, I needed to add an extra rib with two pieces to fill in the gap between the rib and the fuse. These parts were added on with thickened 5 min epoxy for fast working. Later a small strip of .6 mm ply was gleud on top all around the rib.
This way the wing fitted perfectly to the fuselage in the end!
Noël

[Noël Rumers]

…now the fuselage was so far ready that some paint was waiting to be put on! this was not to bad. The striping was a copy paste job from Milan 1. The lettering, I had enough ordered last time for the two models. The only thing that I changed was de G-KORE to the original D-KORE to have two different models but still the same in the end...
The aluminium protecting sheets were made and screwed onto the fuselage together with a few spots of TEC 7. The scale exhaust pipes were fitted as well. Now the rest of the fuselage is on hand to be finished...

[Noël Rumers]

... I never have posted anything on its wings.
The build started last year for Milan 2. The setup is simple. Ply, ribs, spars end glue...
Most of us have a system to do this. I have also one that works for me.
So here we go...
I use Compufoil that suits me best to design all of my wings. The ribs are printed and the paper glued to the ply and cut roughly to shape. I have that way one of each. Then I nail these ribs to a new sheet of ply and cut the two together as close as possible to the line. Next, I grind all down to the very thin printed line, half way the line .
With that done I start cutting the spar slots are done too. Note that all the cutting is done by my hand controlled laser machine
The next thing I do is drilling the holes in the ribs to save weight...a bit... and to be able to run the servo cables through the wing.
The wing joiner tube and incidence pin are also drilled very precise to the spot! I use for all wood drills and I always drill both sides to have a very clean cut on both sides of each rib. Saves a lot of time cleaning the lot from remaining wood splitters on the back side...
The paper is taken off again and a fast rub over the sanding belt clears the glue remains.
All this takes let’s say two days for the wing of the Milan being 45 ribs long.
The spars are sorted too to length before the building can start.
Noël

[Noël Rumers]

The wing joiner tube is made to be fitted into the ribs.
Then on the drawing I start with the bottom spars. They have in the end not much use because there will be a epoxy glass rowing spar in the end in.
So all ribs are glued on with care but it goes fast! The first rib is put in under the correct angle of 3°. I have made a guide to do this.
All is done on the flat table without any help of supporting edges on the ribs. Know that at that stage the wing is very flexible so the lineup is for later.
Note that there are a few ribs that have been laser cut...these come in handy from the previous build the SF27 B M. I changed the wing rib distance on that one. I kept these ribs and now, it saved time. The TE of the wing gets a 30 mm wide .6 mm ply strip that goes into a slot that is cut on the centre line of the rib rear. The LE however is build up differently.
I use a 2 mm 25 mm wide balsa strip that goes into a slot cut to level with the wing cord line. This strip sticks out front of the nose of the rib with 5 mm. Both top and bottom get than a 5 mm thick balsa strip. That strip is shaped to the top and bottom line of the wing rib.
In the end that 5 mm strip is still 10 mm short of the real LE most forward point.
Another 10 mm LE strip will be added much later to finish the job.
The aileron spars are also glued in top and bottom and shaped to the top of the ribs.
Noël