How To Make A Dough Mixer/Kneader ?
We are working with batches of dough that fill a 20 litre bowl. About 5.3 US gallons I think.
That is as much as we can handle: mix up, knead. It gets very stiff, pretty hard work.
So we'd like a machine but commercial machines this size cost thousands of dollars, it seems: http://www.foodequipment.com.au/downloads/pricelist/W_201205_R-PRICE_FED_AUNZ_v11mR3a_A4.pdf 
I wondered what they did before the age of electricity. Must have used a manual machine. Perhaps we could get an old one of them. Or if we could see a few maybe get enough ideas to be able to make one.
Anyone help with that?