Thank you , this is exactly what I am looking for . A way to provide air without modern resources in case things go badly . Having to use simpler methods to still make or repair items .
I saw a documentary on the WW2 "The Great Escape" where archeologists and survivors of the camp dug up one of the collapsed tunnels. In the mud/dirt was a bellows of a very similar design. The bellows were used to assist in ventilating the tunnels.
The piston bellows came from S.E. Asia. - From Wikipedia "The bamboo piston-bellows technology was also adopted early by the Chinese, replacing the indigenous Chinese leather-bellows technology completely." Nice video.
I build mine according to the Japanese box bellows design with the separate outlet box simply because most of the plans available are to do with the Japanese design. It works fantastically with a good airflow, and has allowed me to bypass noisy electric blowers. It is good to see a tube on the Chinese version. The main thing with box bellows is that it is sealed properly and the main box in which the piston slides is squared up correctly.
I'm now making one on my next two days off. I'm making it, because I'm a hobby blacksmith whose work is focus on more primitive or manually operated and naturally built forges. At the moment I'm using a natural clay setup, a square side feed top load front access forge. I built it on an oak stand that's covered with a coat of clay 3 inches thick. I dug all of the clay and processed it myself and mixed it with wood ash for a refractory. The forge is built of bricks made from the clay and lined with wood ash and clay.
This is very neat. While there are various designs made with similar operating principles from the Chinese and Japanese sides of old technology, it's more or less the same in that anyone can build one should the need ever arise, provided they have the means, materials and equipment to do so. The Japanese variants have a cloth around the piston with smooth surfaces on all sides of the 'piston well' and use wood slabs on hinges made of unknown material, but anything flexible or can swivel like a metal hinge can be used if one were to build something similar.
