Mirror Ball Rotator

[adambattey]

Hey Guys,

A few weeks ago I gave a mirrorball rotator to a collegue so that he could change the plug on it to allow me to have it plugged into our lighting rig and the motor turned on and off via the control desk. Today he gave it me back and I have plugged it in - it rotates just fine....but it won't stop! Even if I turn everything down, hit the B/O switch - and even turn the desk off - it quite contently keeps on spinning.

Any ideas on how (or if) i can stop this? I don't want it to be rotating through out the the days never mind the shows it is going to be used it as it will distract the audience's eyes.

Hope you are all well,

Adam

[Erwin]

Well,

At the risk of stating the obvious, that means that your rotater is getting power regardless of what your control desk is doing. So, is it plugged into a dimmer? Is your dimmer overridden by the control card in the rack?

If it is in a dimmer, just turning off the lighting board doesn't clear all the dmx data from the dimmers. Did he/you put a profile on the dimmer so that it is always on? If so, re profile it so that it is full at 1% not full all the time. If you turn your dimmers off does it stop?

Simply changing the plug shouldn't cause such an issue, so a little more info would help.

[adambattey]

Ha ha, I had kindo figured that one out! lol! But someone needed to say it!


It is indeed plugged into the dimmer. I didn't have chance before coming home to check whether turning off the dimmers would stop it so i just unplugged it. I also haven't done anything in terms of re-profiling it [partially due to time and partially me wanting to see what you guys had to say before i started barking up completely the wrong tree]. I knew that i wouldn't be a problem with the changing of the plug as i have seen it done and done it in the past. I will give the re-profiling a go tomorrow and see what happens. [it is fairly straight forward right..? ha ha! I'm on my own on this on and flying slightly blind if you couldn't tell! ha ha ha!]

Cheers,

Adam

[rochem]

I'd be cautious about using a mirror ball motor, or any motor for that matter, on a dimmer, unless of course it was designed to run on a dimmer. I've done a number of shows using a spinning mirror ball, and for those I just used a standard wall outlet and ran it through a switch located at the SM's console. Depending on how powerful the motor is, the dimmer may still be sending a small amount of power, just enough to still move the motor.

[epimetheus]

Originally Posted by rochem

I'd be cautious about using a mirror ball motor, or any motor for that matter, on a dimmer, unless of course it was designed to run on a dimmer. I've done a number of shows using a spinning mirror ball, and for those I just used a standard wall outlet and ran it through a switch located at the SM's console. Depending on how powerful the motor is, the dimmer may still be sending a small amount of power, just enough to still move the motor.

I second this. Depending on what dimmers you have, the motor may be too small a load or the wrong type of load (inductive verses resistive) for the dimmer output to function properly. If you want to control it via DMX correctly, then you should have it plugged into a relay module.

[VanJohnson112]

Horse Power and Wattage are huge differences with dimming. I agree with going with a relay for an application like this.

[gafftaper]

Take it off the dimmer for the safety of the motor. No need for anything fancy. Just run an extension cord off stage along the batten and have a technician plug it in when it's time to go.

[kiwitechgirl]

If you really, really want to run it off a dimmer (taking into account all the advice you've already been given!) then put a dummy load on the dimmer channel as well - a spare lighting unit, plugged into the same circuit, put somewhere out of the way where it isn't going to spill light onto the stage or into the wings. It'll stop the problem - even when a dimmer is at 0% there's a small current still flowing and it's enough to make the rotator turn. A dummy load will "absorb" this current and stop the rotator

[Van]

Good Idea from Kiwitechgirl. A dummy load, or Ghost Load could help. Now without sounding too pedantic... are you sure the Motor was still rotating? Mirror ball motors have a clutch which allows the ball to turn after the motor has stopped thus burning off inertia, and protecting the motors gearing from damage. The reason I bring this up is I once thought the same thing, that I had a dimmer that was mysteriously staying on, ' cause the ball kept spinning after I turned off the channel. After close inspection I found it was just "coasting" to a stop. The larger diameter of a ball the more rotational momentum the longer it takes to stop.

[derekleffew]

kiwitechgirl, had this thread remained in the Question of the Day, you would have won, (in my experience). See the wiki entry, ghost load.

See also these threads:
http://www.controlbooth.com/forums/l...mmer-pack.html
http://www.controlbooth.com/forums/l...-circuits.html
http://www.controlbooth.com/forums/s...ng-motors.html

Now, has anyone ever had a rotator that, every time power was cycled, it spun in the opposite direction? I once hung ten or so for a party in a ballroom, and I swear this was happening. Naturally we were on a time crunch so I couldn't prove it, but it was odd to see mirror balls spinning in two directions. (I then discovered the turntable in my microwave spins the opposite direction each time. Freaky!)