Avro 504 N/O 1/20th scale electric

[g_kandylakis]

About a year later, late 2021, work was started on the wings.

Quite a lot of ribs to cut. Being a rather process orientated modeller and an obsessed perfectionist, I cut each one separately, using two templates as guides. I find it much better than making a block of many and sanding it, becasue it is very easy to overdo it and damage the templates if one is not careful enough. Also the ribs might not be 100% exactly the same. Not that anyone would notice...

The fact that I prefer the spars to be inside the ribs and thus require accurate slots helps in that decision.

The rib front and rear ends were made oversize, compared to the corresponding leading and trailing edges. These would be pre-shaped and it is much easier to sand the ribs to their shape than the l.e. and t.e. to the ribs.

The less anomalies thre are on the structure the better the covering goes and shows.

[g_kandylakis]

a simple sanding jig for the trailing edge, using metal rods for the needed final cross section. 5cm long is enough, you sand and push the jig to a new position, sand again etc.

[g_kandylakis]

The aileron trailing edges were curved, so at first they were sanded to triangle shape, then stripped lengthwise, weted in water and glued to a form as laminations. Some final fine sanding was also needed afterwards.

[g_kandylakis]

shortly going back to the ribs, the slots were cut with self made tools, using carbon steel pieces glues to sticks. The carbon steel breaks nicely and straight, it is very sharp to cut balsa vertically.

[g_kandylakis]

seing here enlarging the slot for the aileron ribs, for the extra aileron leading edge.

Some fine sanding with small diamond needle files ensure a very clean and accurate outline.

[g_kandylakis]

The spars are soft balsa sandwiches, with a thin carbon piece in the middle. This provides great strength against deformation to the finished wing.

They were made slightly oversize and sanded after glueing to the exact cross section. Working with CA does not give a lot of time for proper alignment.

[g_kandylakis]

repetition, the high tech sanding jigs for the leading and trailing edges.

The leading edge was made of basswood. I think the extra strength came handy whenever the model hit an obstacle with the wing

[pedwards2932]

Wow!  Your attention to detail is amazing.

[g_kandylakis]

Thanks Philip...

wing construction. The oversize ends of the ribs are visible.

The ribs slot into the triling edge. The slots were marked and opened with a simple sanding tool of exactly the same width and fixed depth.

[g_kandylakis]

left wing panel, slowly coming together

[g_kandylakis]

the ribs are slotted into the trailing edge and to keep them in place extra sloted balsa pieces were made, to keep them vertical as well. Once in position they were glued to the leading and trailing edges.

The extra pieces allow temporary fixing of the ribs while the spars are being pushed through them. The ribs are thin, about 0,6mm so they might break if the spars do not go clear through their holes.

There are 4 wings panels, so it makes sense to auotomate the process as much as possible to avoid through-backs.

[g_kandylakis]

Tpo wing center section done.

Aluminium tubing glued on center section and wing panels, piano wire connects them and sets the initial dihedral angle.

[g_kandylakis]

...

[g_kandylakis]

second left wing panel done, moving on to the right ones.

I was a bit lazy at that point and did not make the laminated outlines one time. But I continued with the next panels anyway.

[g_kandylakis]

same old same old...

the aileron trailing edge had to be glued upwards towards the tip, because of the curved outline. A bit of trial and error until it looks about right.