A few of my RC Scale models

[John McNamara]

Hi All,

I though that I woud share some images of my RC scale models from over the years. This is just for general interest and chat.

This first one is of course an F-86 Sabre. It was to 1:5 scale. It flew very well, but came from a Chinese manufacrturer of questionable credentials. It was severly under-engineered. I let it go to a Swedish Guy who had the time to pull it apart and rebuild it properly. It looked fabulous just doing low, sweeping fly by's.

This F18 E Super Hornet was from another Chinese manufacturer. This one also looked wonderful but the aerodynamics were dodgy, making it very hand to land safely. This is quite an old shot. You can see the "whip" aerial. We have not used this system for about 10 years.

Now for something completely different. This is a 1:3 scale model of a 1936 Polish Orlik 2 sailplane. It is 5 metres span, built from  Polish kit. It flies superbly and look gorgeous.

That's all for now. I'll be happy to answer questions if there are any

 

John

[Farmerboy]

They look crazy good John, knowing nothing about R/C what engines do you use on the jets? They must be very small and very powerful.

[John McNamara]

Hi Farmerboy,

Yes they are, and they keep getting smaller and more powerful. Both the F18 and the Sabre had 160N engines in them. The sabre was a bit overpowered by the F18 was just about right. It was very fast when clean but need lots of throttle on around the landing pattern with everything hanging down.

The engines are simpler versions of what Frank Whittle designed, i.e. centrifugal single stage compressor, Single stage turbine wheel made from inconel and an annualar combustion chamber in between. The run a total loss system, so we add about 5% turbine oild in the fuel, which is driven through the ceramic full contact bearings, prior to entering the individual combustion tubes. These act as flame holders, and inside them are the fuel injection needles, the i.d. of which is about the same as a human hair.

So basically a very simple design in principle. However the demands on enginerring accuracy and material technology is extreme, so they are expensive.