What are the treatises on how to build mechanical computers?

I've just watched this replica of the Antikythera mechanism. I've heard also about Babagge's analytical machine and the Curta calculator. I got curious: What did they use to build computers made of gears? We have nowadays some treatises to make logic gates with transistors, how did they manage to build logic gates or to do whatever was needed for building their computers?

I'm not sure if this question really fits this forum, but it was the nearest one I could think about.

This is a very broad question, with a different answer for each kind of device.
The computers before modern times did NOT use logic gates.

For example the January 2004 Scientific American article "The Curious History of the First Pocket Calculator" covers how Curta calculators work, in addition to the history.

The Antikythera mechanism used gear reductions (gears with differing teeth counts) to implement the ratios of times of various periodic events to predict positions. Given the [known even then] frequencies, it is straightforward to compute the required gear ratios. http://www.cs.virginia.edu/~robins/Decoding_an_Ancient_Computer.pdf

In addition (as mentioned in a comment above) there were many many different flavors of analog computers, that a quick google search should be able to find explanations for many of them.

StackExchange Computer Science Q#24624, answer score: 2