RE: CD ScaleDesigns Albatros CI build
 

In my Alb. CIII i have the CG position at 22% of the chord of the upper wing; a bit nose heavy but a lot "safe" in particular in the landing

RE: CD ScaleDesigns Albatros CI build
 

Francesco,Is your Ciii a Darrell Hansen design.If so,what angles did you set the stab and wings?The wings have 2* dihedral and both wings are in line,no staggering-Jeffo

RE: CD ScaleDesigns Albatros CI build
 

Jeffo
No, my Albatros CIII is from my own plans; 1/6 scale and all the angles , incidence and wash-out are like the original; the airfoil also is from original 1915 drawings.

RE: CD ScaleDesigns Albatros CI build
 

Francesco,What did you set the wing incidence in relationship to the stab.-Jeffo

RE: CD ScaleDesigns Albatros CI build
 

As from 1915 J. Lagorgette drawings:
upper wing +6°
lower wing +6°
Stabilizer +2,5 -3° (with possibility to adjust this incidence +/- 1,5°)

RE: CD ScaleDesigns Albatros CI build
 

Francesco,I measured the plans and came close to the same results.
Both wings 5.5* pos.
stab 2* pos.
I was a little concerned with the wing incidence,but my guess is why they have so much incidence is because the airfoil is so thin.-jeffo
,

RE: CD ScaleDesigns Albatros CI build
 

I believe that if my Alb flies so well in 1/6 scale in a bigger scale (1/4) it should fly only better

RE: CD ScaleDesigns Albatros CI build
 

That would be my guess too. On my CI I'm just trusting the incidences that Chris used in his design. I know they are not "scale" but I know that Tom's CI flies well.

RE: CD ScaleDesigns Albatros CI build
 

In Italy we say "nessuno ha la veritÃ* in tasca" that sounds like "nobody has the Truth in his pocket"...;)

RE: CD ScaleDesigns Albatros CI build
 

Ain't THAT the truth! ;) :D

RE: CD ScaleDesigns Albatros CI build
 

Just a quick reminder,  The heavily positive incidence was due to the nature of the undercambered airfoils.  The had their own positive incidence built in. 

RE: CD ScaleDesigns Albatros CI build
 

Also, at that time, climb rate was very important. It is less so for us as we stay on the ground and so are always adjusting the flight for our fixed vantage point. Most R/C fliers are more comfortable with less difference between the wing and tail incidences. However, the originals are perfectly usable if you don't mind using the throttle more for climb and descent.

Martin

RE: CD ScaleDesigns Albatros CI build
 

Step by step, experiment by experiment, the quest for the best looking covering goes forward. After multiple tests, problems remained with the silk-applied-with-PolyC approach. For one, the PolyC really doesn't function effectively as an adhesive to stick the edges of the silk to the underlying fabric. Second, no matter what I tried, I was still getting a sandy texture to the silk even after 2-3 coats of PolyC. It was as if the PolyC was somehow "raising the grain" on the silk. Also the PolyC seems to render the fabric+silk combination almost transparent (almost like yellowed plastic). But perhaps worse of all, when I tested the PolyC over the Polyspan I got both sandy grain and wrinkles (maybe caused by differential drying), so that was no good at all.

So I went back to basics. I covered a test frame with Natural (uncolored) Solartex and then applied a coat of non-tautening Nitrate, then the moistened silk is laid down and smoothed out with a fingertip. And then more non-tautening Nitrate is brushed through the silk. And that seems to do it. Once the second coat of nitrate dope is applied, the rest of the weave can be filled with either PolyC or Butyrate instead of the nitrate (of which I have only a limited supply). This still isn't going to solve the problem of the black CF tubes showing through, but I may just have to accept that. I've done tests where I sprayed the frame with grey primer, but I'm not sure that's really an improvement. Actually the silk is fairly opaque after the first "thin" coat (as seen in the test piece towards the tip) but goes more transparent with further coats. I was hoping I could just add the PolyC after the initial doping to keep this more opaque look, but this creates an uneven look where the PolyC goes where the dope hadn't.

I've added a couple small swatches of Solartex Linen and Antique for comparison purposes.

RE: CD ScaleDesigns Albatros CI build
 

Why not spray a coat of wood colored paint over the primed CF rod? Then the see through framework would look quite natural. .......John

RE: CD ScaleDesigns Albatros CI build
 

Actually, on the original CI the entire stab, elevator, fin, and rudder were made of steel tubing which would have been primed and then the edges wrapped with fabric. And according to Matz, the original linen isn't translucent enough to see the structure anyway. So my covering solution isn't perfect in this regard. One of my test during this week was to add white paint to the PolyC before applying the silk but that resulted in it's own problems.

This photo shows the test over the primered frame.

RE: CD ScaleDesigns Albatros CI build
 

I've also experimented with priming the frame with "rust" primer, white, and silver. The only thing that can be said for pre-painting the structure is that is at least all one uniform color. Also it IS possible to apply Stix-it (and dope) over the primer, through if you apply it heavily it eats into the primer, so thin coats are best.

RE: CD ScaleDesigns Albatros CI build
 

Tail feathers primed and ready to cover.

RE: CD ScaleDesigns Albatros CI build
 

Neat website:

http://jasta11.co.uk/index.htm

RE: CD ScaleDesigns Albatros CI build
 

Yeb,

Tail parts are looking great Don [8D]

RE: CD ScaleDesigns Albatros CI build
 

The tail feathers are now covered with Solartex Natural. The next step will be to dope on the silk for the color. This shouldn't be as bad as covering everything again. It's more like "painting on the silk."

RE: CD ScaleDesigns Albatros CI build
 

It is too bad the covering is not just a little off of white. It would look like a plane new out of the factory. Looks good.

RE: CD ScaleDesigns Albatros CI build
 

Not really. German CDL wasn't yellowish from weathering. It was yellowish because the raw unbleached linen itself was beige/tan and this color was made even stronger by the varnish used. That is, the varnish gave a warm tone right out of the can. As near as I can tell the color of my test pieces covered with silk is what the aircraft looked like right out of the factory.

RE: CD ScaleDesigns Albatros CI build
 

Still it looks quite nice.. Reminds me of clear doped silkspan.

Martin

RE: CD ScaleDesigns Albatros CI build
 

The only parts still uncovered are the ailerons. I put off covering those while I looked into what material to use (Solartex) and whether I might consider making the structure more scale (no). Well, maybe no. :)

Adding the silk will be a big job...but perhaps no bigger than painting would have been. But before I add the silk I'm going to give some further thought to how I might do rib-stitching with this "no paint" method. I made some interesting attempts earlier they were all a bit too crude looking.

RE: CD ScaleDesigns Albatros CI build
 

After thinking long and hard about methods for doing or simulating rib stitching, I've concluded that none of them are really satisfactory and/or compatible with my silk-CDL approach. I had some initial success reproducing the Z-shaped stitching but the were far too wide to be scale...sort of like having giant rivets on a WWII model. So for this model, I think it's best just to leave them off.