Controlling the motion of a clock

[snoeret]

I work with a show where we will need a clock that we can control the motion of the hands of. It need to be able to move backwards and forwards and fast and slow and it would be awesome if this could be done from the lighting console. But really any way to control it remotely would do.

Any help would be rewarded with great thankfulness and my everlasting respect!

 

[n1ist]

I'd start with an older clock, with an AC synchronous motor in it (as opposed to a battery version). It's much easier to remove the motor on them. Then swap the motor with a stepper. Alternatively, you may be able to couple the stepper to the time-setting knob. For a quick one-off, I'd use an Arduino and motor shield to drive the stepper. Driving it from the console would require some simple software that takes three channels of DMX (direction, speed, and desired time at end) and uses that to drive the stepper.

If you don't have to go backwards, you could drive an AC clock with a vfd or even a sine-wave oscillator and power amp.

/mike

 

[LightingGuy89]

I've had luck in the past with a DMX control board and a servo (think of the kind that drive a color wheel in a moving light). I think Fleenor may actually sell the DMX circuit board and you just need to provide a 12v DC PSU and a servo that will respond accordingly.

 

[derekleffew]

Another option:
http://northlightdmx.com/DMX512toRCservo.htm

Northlight's RC servo controllers will receive DMX512 digital protocol for Stage lighting products and controls 8 RC hobby servos.
Our controllers have rock stable output, no jitter at all.

 

[JD]

Here's another DYI DMX solution : http://www.bpesolutions.com/dmxproduct.html#anchor936831

 

[dbaxter]

If you have a buddy who is a radio controlled airplane or car hobbyist, they may be able to loan you a receiver and transmitter to drive a servo. You won't get 360 degrees of rotation, only about 270. For 360, you'll have to go the stepper motor route.

 

[n1ist]

Or use the RC servo and some gears; not much torque needed to swing clock hands.
/mike

 

[Fountain Of Euph]

A broken scroller may work too. Use a belt to connect the drive wheel to the hand shaft on the clock

Sent from Taptalk for Android, this was.

 

[Calc]

What kind of clock? We did an adaptation of A Christmas Carol back in college and I rigged up a Flash animation that we projected onto the faces of a clocktower. Once it's a projection, you can do whatever effect you want with it.
Even though it was front-projected, it looked on stage like the clock was backlit, and fit in with the rest of the lighting. YMMV.

 

[kicknargel]

I've also seen someone solder shafts to the center of a couple gobo blanks and use a twin spin indexing gobo rotator to control a small clock. One shaft was a hollow tube and the other sleeved inside it.

 

[VCTMike]

I've also seen someone solder shafts to the center of a couple gobo blanks and use a twin spin indexing gobo rotator to control a small clock. One shaft was a hollow tube and the other sleeved inside it.

That's pretty adventurous and must've been tricky getting it assembled in the twin spin....