Drilling the rudder

Marked all lines and holes and drilled the rudder skin to the skeleton. Also made the strips to fasten the fiberglass trimming and details.

Fixing rudder

Finished trimming the rudder skin. Cut out the slots for the hinges. Used cutters for a rough cut, then a dremel for the rounded corner and a file to get straight edges.

Fighters, another look

Digged out an old SOM software that I made some 10 years ago. SOM = Self Organizing Map, and is a kind of artificial neural network that maps multidimensional vectors on to a 2D map according to a highly non-linear algorithm. On this map, similar vectors become clustered together, while non similar vectors are far apart or have "mountains" between them. It is used for instance in match-making software, image analysis, pattern recognition and so on. A SOM will only show the relative differences, nothing more.

The basic data for an airplane is a typical vector. So I simply feed the SOM with airplane data (several T/W and wing loading data and some other stuff), and let the artificial neurons do their job making some maps.

On the first picture, the map became devided in two distinct regions. "Real" fighters are on the left, while more fighter bomber planes are on the right. The Gripen and the Rafale are also somewhat isolated from the rest of the fighters. The F-35 is very similar to the F-18E. So, the F-35 is for all practical purposes (practical in a T/W ratio, wing loading sence :-) ; a stealthy F-18E. If this is good or bad, I don't know, but the F-35 is certainly no real fighter in a "classical" sense relative to the fighter bunch.

On the other picture I have "hard wired" a mystery plane in the middle and let the SOM work to see the similarities with the others. Clarly the mystery plane is very different from the rest, probably much better looking :-) But, it has to be built...

Trimming rudder

Started trimming the rudder for hinge points etc.

R-410

Time to do some work again. Started with cutting and filing R-410 into shape. Spent some time studying how to cut/trim the rudder, but I'm still not completely sure in which sequence this should be done.

Bending the rudder skin

Bended the rudder skin and started mounting the rudder jig. There is a lot of trimming to do on the rudder, and I need to mark all that before assembling (I'm not entirely sure if it is best to cut everything before riveting). Ordered "RTV 3145" from Aircraftspruce, probably the most expensive glue ever, 33 US$ + shipping for 4 oz (118 ml), a Christmas gift all by itself, he he. This is needed at inside the trailing edge of the rudder to prevent cracking.

Rudder skeleton riveted

Riveted together the rudder skeleton. At first it seems like the rudder is fastened to the rod end bearings with only two rivets each, so that only six 2/16 rivets are holding the whole rudder. But when looking just a bit more closely, the rod ends are really holding the rudder with the bearings and the rod end nut squizing the plates and spar together. The six rivets are only there to keep the jam nut positioned. Nice design.

The jam nuts on the rudder seemed to be bare steel, so I primed them using the zinc chromate rattle can.