DISPLAY ROTARY AERO ENGINE

By Penelope Jamieson

The inspiration to build the engine came from watching a film called The Blue Max and I saw them starting up what I think was a Fokker triplane. I noticed that the whole of the crank case and cylinder blocks were rotating and after some investigation I found that rotary engines and radial engines though looking almost the same were very different.

I found that a book about their maintenance had been published by The Air Board in 1917 for the RFC and RN) and had been reproduced by Camden Miniature Steam Services in 1997, I managed to buy a copy. There were no design details so I set about designing my own, guided by some of the maintenance notes and pictures in the book. I did a sketch of the crank case and cylinders but mostly I made the parts from my head direct on the mill and lathe.

The first cylinders I made I used aluminium tube but the extrusion process had given the material hard and soft zones and getting a good finish was impossible. So all the cylinders, pistons and cylinder heads were machined from solid.

The model was never meant to be a faithful reproduction of an original, it was meant to show how they worked which is why I have done cutaways in the cylinders and crank case. In short it was meant as a quirky display item.

I am mostly retired but still act as a consultant for a couple of engineering companies. I was CEO of various engineering companies around the world and specialized in heavy metal forming for the oil refining industry. In 2015, for my consultancy, I asked companies to make a particular CNC machine I wanted but they refused saying they could not work in the way I wanted. So I bought a little second hand lathe and a small milling machine and made a working model of what I wanted including writing all the trigonometry and programming the controller. I took it to show them and they then built me the full size one. That was my first foray into model engineering. I have since updated my workshop machinery (WARCO WM250V lathe and WM18 milling machine) and now enjoy playing at making things.


Also from the workshop are brass Rubik's Cubes which were interesting to make and make for a nice display item but, at 1.8kg, you are more likely to break your wrists than speed solve them. (Ed: For a future article we have some pictures of them and drawings of the individual cubes and details of three fixtures needed).

https://www.sarikhobbies.com/model-engineer-builder/

Modelengineeringwebsite.com

the only free and the only weekly magazine for model engineers. 

Editor: David Carpenter