Trinery Arithmatic

[Hand-E-Food]

A simple idea.  Can you make do with what you have?  Go wild!

Trinery Arithmatic:

dubynod

[Handi]

The best puzzle I've done so far! Really nice one Hand-e-food, thanks!
  Trinery Arithmetic Solution: gabigyh

I had some troubles with timing at first... then I thought about one of the oldest timing devices designed in history, which's principle is still very used today... the pendulum.

[Rene]

Smart concept for this puzzle;  I enjoyed doing the solution:

tyvubem

EDIT: I just looked at Handi's solution. I just love the way you did a lookup table! And the mechanics for how the actions are performed is very smart.
You may be able to implement a general computing machine that way. A program for such a machine would be a string of letters, you have 16 different actions that can be performed.... add, substract, test on 0, jump forward and backward in the program...

EDIT: Just decided to tidy up things a bit. The solution now even more compact: judidul

[Handi]

Yeah, that would be neat... however, when you think about it, where could you need such a device, lol ?!
Anyway, I looked at your solution, I must admit it's very nice and much simplier then mine and actually, it's what I wanted to do at the beginning, I just didn't see a way to automatically identify the value for each digit (+, - or 0) for the selected number... and then I thought about my 'operation machine' and was completely hypnotized by the idea... 

[Hand-E-Food]

Wow!  I thought I'd made it way too hard not providing a replicator for at least the output barrel.  Those are both amazing machines!  I've wasted about half-an-hour at work just watching the intricatness of Handi's solution.  I don't think you could make a more accurate representation of a computer.  My first (brief) attempt was similar to Rene's, but I couldn't work out how to replicate the output barrel (how you used gates.)

[jf]

Finally, I have solved dubynod. I hit several dead ends since this puzzle was first posted, and then I was intrigued by this comment of a table-driven solution, but could not think of anything (I have not seen any of the solutions yet). Eventually, I went back to study the numbers and then, Eureka! I found a cyclic pattern that I had overlooked before. Voila: lucehis.

Edit: Handi and Rene, those solutions are fantastic!