RC-SIM

The oil coolers look quite difficult, but they are easy to build.
At first we need some photos where they can be seen better than on the 3-view.
On the 3D-model I have cut the wings horizontally with “Knife” to get additional rows of points.

The outer shape of the cooler is complex with strong bending. There we need more rows of points. Therefore “knife” several times here.

I have then selected the lower row of points and have moved them a little down with the “Edit Panel”. Then move the points of the transition to the correct position and the basic face is ready.

Now in detail:

The inlets for the oil cooler are made by deleting the front face of the “bulge”. Then select the edge and move it with “Pull” to the inside. Adjust the points a little and it looks like this:

If you “pull” the edges to the inside again, you will get an additional row of points. You can use the first one now to create a small taper. Therefore just shrink the new inside faces a little. The closing face is added by hand.


Later the closing face will get a texture.

Next we come to the engine hood. I still looks a little “unfinished” but we will change his now.

At first I copy the outer faces of the hood into a new object and switch it invisible.
The same faces are still at the fuselage-object. I delete the front faces with the bend and pull the other faces to the inside. Then I close the fuselage with a few faces.

Then I come to the hood itself and pull the central point of the front face forward (the hood is now tapered).
Then I cut the cone with “Knife” and scale the create row of points accordingly (so that I can push it inside the hood).
This I do several times row by row to get the inner shape of the hood.


Finally I delete the front-cone and get a nice engine hood. It isn’t finished yet!

Now we come again to a more difficult part:
The covers of the cooler-outlets.

The problem is: If you open them a little they should be displayed as single covers. Therefore they must be displayed a single volumes, so that between each cover there is a small gap. This gap must be closed with a face.
Here we must create many small faces by hand.

At first we draw a line (“Line”) across the trailing edge of the canopy and delete the faces that later will be the covers. This faces are joined to each other and therefore we can not use them later. With the line we “remember” the positions of the important points. You will find out later what this is good for!

Then I cut with “Knife” this line to the left and right of each point (near to the point) and equable on both sides.
With this we get additional points on the line. On the top-side I skip to parts of the line because the covers do not go around completely.

Then I join the new points on the outside with the edge of the canopy by using multisided polygons. With this procedure I get a small gap between the new faces.

Next I create the side-faces between the covers. These are small triangular polygons. It is very important here to turn the front-side (paired together). You must work very accurate here!!

If you have managed this, the rest is easy:
With rectangular polygons you must close the insides of the covers. On top we leave two of them open.


Now you can set the selection filter to “ln” and delete the line on the trailing edge of the cover.

If we switch everything to “visible” we can have a proud look on our work.

The engine hood is still not finished yet!
More of it in the next part.

QUESTION:
How does it work with “freeze”, what prerequisites are necessary?
“If I try to mirror the fuselage parts with “Freeze” (like explained in the workshop) I always get the message “Fuselage isn’t attached any attributes to freeze”
Up to now I have always done this with “Select/Mirror”.

ANSWER:
At first you must switch on the option “Separated” in “mirroring” (in the object properties). Only then you can use “Freeze”.

In my opinion this is very practical because with “Mirroring = Separated” you can see one editable half as grid lines and the other part as some kind of preview. You can see quickly the effect if you move a point.

With “Freeze” you freeze the complete geometry.

But you should check if all points on the mirror axis are connected.
This you can do easiest if you select “Join closed vertices” in the “objects” menu.
Normally some points are eliminated then and the transition of the geometry gets very fine.

But be careful. In very small models it can happen that also some other points are joint because the smallest possible value is maybe still too big. In such cases I built the model in double size at first and downscale it before exporting it to AFP.