Corner bracings

I added all the corner bracings. I guess this process is done „on the fly“ in reality. No one will cut these chips according to any drawings. Theese small wood chips (well, card chips) are backed uo by additonal struts which run parallel to the ribs. Pretty straight forward:

Stege 1CornerCorner_enforcementsCorner_solution

Bracing walls

I designed these two elements according to the drawings and positioned them according to the drawings, and….bam, doesn’t fit:

Intersection Pushwall

Problem is, the diagonal struts collide with the upper and lower strips of the bracing wall. And looking closer at the drawings I found that they cannot fit as the strips all run at basically the same height. I wouldn’t be surprised if each and every builder of the SG-38 ran into this problem. The solution is either quick and dirty -> forcing the struts under the strips and thus compomising in stability, or having to rebuild the bracing wall completely. One third solution is possible: The drawings I have are rather foggy from the copying process. So I might have misinterpreted some of the dimensions.

Anyway I redesigned both walls and stretching everything a bit and I was able to sufficiently squeese in the diagonals:

Schubwand_korrigiert_detail

The opening that is visible in the wall is for the aileron control lines.

Diagonal struts

Man, this is tedious. At first they looked like simple 1x1mm struts, easy to attach. However each of them is a bit different. And putting this into a building instruction is a nightmare.

I will probably just cut the stock itself to be cut to fit.

Next (well honestly the first) problem I ran into are the two lengthwise bracing walls. These were obviously added afterwards. See next post.

checking_alignment

Heavy metal

Thinking about making the fittings, hinges, rolls and everything made me look for sources of allready available parts.

I came across a supplier for large garden railways:

http://www.knupfer-grossbahn.de/

The offer a wide variety of norm parts, especially very small screws. Finding these I decided to use real screws instead of fake ones. I also found appropriate rolls that can be used for the control lines. Some parts may be used for making hinges and connectors. The even have steel wire starting at 0.3mm. Mmmhhh, am I going to make functional controls. Yes it is a bit overdone….on the other hand worth a try 🙂

Adding the wing tips

Next step was adding the wing tip. This is made of laminated pine strip and I will represent it using three layers of cardboard.

At this point I noticed that the washout of the wings is allready included in the spar design. Adding the wing tip completely horizontal ended in a misalignment:

Randbogen Problem

But adding a few degrees of twist brought everything into a perfect fit:

Randbogen_perfect fit_Holm needs cut