Avro 504 N/O 1/20th scale electric

[g_kandylakis]

once drilled, an orientating piece of 0,5mm music wire was added and the tubing was inserted into the sloting jig.

[g_kandylakis]

a very fine saw blade cut the slot. The jigs ensured all four parts came out equal.

[g_kandylakis]

next step was to sand the ends to a round profile, using pieces of aluminium as guides for the sandpaper

[g_kandylakis]

final step was to press the sides together, with a piece of aluminium sheet as a limiting spacer.

6 pieces were made, although only 4 would be needed, in case something went wrong. It is more difficult to go back for an extra piece, psychologically at least.

[9600baud]

Wow! Excellent use of gigs! Love it!
I have to remind myself to use more gigs to solve these kind of problems

[g_kandylakis]

Hi Alex,

yes jigs can prove most helpful in many situations where repeatability is an issue. They do not have to be very elaborate, sometimes the simplest things work wonders.

Going back to the Avro, the cowl panels would be made of polystyrene sheet, to simulate the metal sheet of the original. Given the various curves, these would be vacuum formed, so a plug had to be made.

Starting with the side view and some cross sections, using plenty of balsa fillers and sanding, the basic shape was achieved

[g_kandylakis]

some more sanding and grain filling improved things even more

[g_kandylakis]

again some temp assembly photographs, quite a waste of time but necessary to keep the motivation and the build going forward.

[g_kandylakis]

Brass rod hinges have been added at this point to the horizontal tail surfaces.

[g_kandylakis]

the rudder was hinged differently, similar to the original

[g_kandylakis]

The cables to the control surfaces would normally be fairly easy to replicate. Since however they are to be functional and thus need to have as little friction as possible, it was necessary to route them properly.

The exits from the fuselage are clearly defined but they need to turn inside the fuselage, so an internal former was added, with short aluminium tubes bent to the required curves to guide the cables.

[g_kandylakis]

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[g_kandylakis]

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[g_kandylakis]

one of the weirdest parts I had to make was a universal joint for the front landing gear legs.

To it attach the front legs, the wheel axle and the horizontal tubes that go to the "V" struts.

Simple enough, only it had to allow free movement of each wheel up and down, like an independent suspension.

To design it was one thing, to make it was another. Especially in the size of a few milimiters.

Much to my surprise, carbon sheet worked great for this, together with CA.

The right part is the finished first one, the left one is the preparation for the second one. A lot of sanding to get there.

[g_kandylakis]

and the final result