My suggestion would be to use a stepper motor instead of a timing motor to run the clockworks.  That way you could not only control the DIRECTION of the motor turning, but also the SPEED.  There are numerous kits for stepper motor controllers, and the motors themselves can be fairly small and not too expensive.  Good luck!

I recently had to do something like this for a production of Blithe Spirit and I took an even lower tech approach. The clock mechanism in the clock we used had a dial on the back used to set the time. I simply hot-glued a dowel to the dial and put it through a hole in the flat where the clock was hung. Someone could then spin the hands either way from backstage.

Originally posted by dboris I recently had to do something like this for a production of Blithe Spirit and I took an even lower tech approach. The clock mechanism in the clock we used had a dial on the back used to set the time. I simply hot-glued a dowel to the dial and put it through a hole in the flat where the clock was hung. Someone could then spin the hands either way from backstage.

I like that way better than mine. Great idea!

All of these ideas are fine (except I would think the "electric drill" concept would be too noisy) as long as you are only moving the minute hand.  If you want it to look like the clock is REALLY running forward and backward as a real clock would look, you'll have to use the clockwork (the hour hand also moves as the minute hand goes around).  That is why I suggested the (relatively silent) stepper motor technique.  It is really a very simple way to do EXACTLY what you requested.  Come to think of it, the idea 'dboris' suggested still uses the clockwork so that would work nicely, too (as long as the hot glue hangs on).  No matter, best of luck with whatever you do.

Edited by Spectrum - 9/21/11 at 6:33pm