Mechanical calculator design problems

[kevjcarvalho]

hey...i have designed a mechanical calculator...i am using spur gears, bevel gears and stepped drums(Leibnitz drum)...my design is ready but the problems is how do i decide the dimensions of the gears like thickness, diameter etc...do i just select a convenient size...or do i do some analysis...if yes what analysis?...all my components will be made from nylon...custom made...please help...i have attached different views of the model with the frame removed...

 

[Bob S]

Why? Natural gas flow meters and car odometers both have rotating dial mechanical readout with decimal carry. Copy them. About 40 years ago I sold my mechanical Friden desk calculator with multiply and divide for $25. I suspect you can still find them (or Marchants) in 2nd hand stores.
Bob S