Scale Facts-Rubber in compression undercarriages.

[wonwinglo]

There are so many different types of undercarriages used on aircraft that I think it best to split them up for seperate description,I am going to start here with one very familiar to myself as I once overhauled these particular types of unit in my aircraft engineering days-The rubber in compression type of undercarriage was used on quite a few De Havilland types,probably the most famous being the Mosquito,the same type of gear was also used on the De Havilland Dove & Heron types which is the particular machines I have overhauled,these undercarriages are not only sturdy but are easy to repair and overhaul in the field being so simple,first we have the magnesium outer undercarriage leg together with a brass inner sleeve,into this is attached the highly polished chromed leg,in the sides are the usual grease points and brackets and clips which hold any brake pipes etc,at the lower end are the usual torque links which attach to both the inner and outer leg,these prevent the sprung inner portion from twisting and also support the lower portion.So how is the leg sprung ? well imagine a piece of steel rod onto which one end is threaded,onto this are placed large circular washers interspaced with circular blocks of solid rubber,on goes a washer then the rubber,and so on until the entire length is filled in this way,the rod is then offered up inside the inner leg and locked into place.

Some compression is adjusted into the assembly allowing for the weight of the aircraft,the springing is quite hard by modern standards but rest assured will withstand the hardest of landings on both grass and tarmacc surfaces.

By understanding how the real designers do these jobs gives us a deeper understanding of how we can detail our models more realistically.