Mirror Ball Rotator

David Ashton

Well-Known Member
Joined
Sep 8, 2007
Location
perth W Australia
Another example of Chinese innovation.
 

PhantomD

Joined
Mar 3, 2006
Location
Brisbane, Australia
I remember this topic was discussed a while ago. LSC Lighting Systems had a really good technical newsletter on this very issue, however I cannot seem to access it now.
 

David Ashton

Well-Known Member
Joined
Sep 8, 2007
Location
perth W Australia
"Innovation or duplication?"
I deal with China a lot and there is innovation and a lot of Patents applied for and some really well engineered and expensive gear, as well as the junk.
 
Joined
Sep 5, 2009
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/lighting/2210-miiror-ball-motor-dimmer-pack.html
http://www.controlbooth.com/forums/lighting/11561-constant-power-dimmer-circuits.html
http://www.controlbooth.com/forums/special-f-x/9547-dimming-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!)
Freaky indeed - I just found this forum by googling my problem, which is that my disco ball rotator (which I'm using for a totally different purpose) changes direction when turned on and off and on again. Only it is not even consistent in that - sometimes I have to turn it off and on again 3 times to get it to change, sometimes it changes every time. It's driving me mad! Any idea how to stop it doing this or am I just going to have to get someone to check the direction it's going every morning when they turn my gallery installation on? The motor itself is sealed, so I'm guessing I've got no options here... Thanks for any advice!
 

00AVD

Active Member
Joined
Sep 7, 2007
Location
Brisbane, Australia
In your case, it's going to be random. The only way to resolve the issue is to buy a mirror ball rotator that uses a DC motor inside. The one you have uses an AC type.
 

David Ashton

Well-Known Member
Joined
Sep 8, 2007
Location
perth W Australia
if you buy one of the dmx motors mentioned you can set your speed and direction and change it at will.
 

kailashed

Member
Joined
Jun 22, 2010
Location
singapore
Induction motors can do this. Some have an extra part (shorted turn?) to force them to always start in the same direction. As you've seen, the unknown starting direction can really play havoc when you've got more than one! :lol:
Hi, I am also having a problem with 2 mirror balls spinning in different directions. I am trying to get them to spin in the same direction. I have already bought these motors. Is there anyway to modify them to "add" this extra part(shorted turn?)

Thanks

Kailash
(freelance theatre practitioner)
 

David Ashton

Well-Known Member
Joined
Sep 8, 2007
Location
perth W Australia
No, there is no way, incidently there are 2 basic types of dc motors, some have permanent magnets, these will change direction if the wires are reversed, some have electromagnet fields and these will always go in the same direction as when you switch wires, you reverse the magnetic fields in the rotor and the stator, this latter type are universal motors and will run on ac or dc and to reverse them you reverse either the field winding or the rotor winding but not both.
 

ship

Senior Team Emeritus
Premium Member
Joined
Mar 29, 2003
Location
Illinois
One thing not discussed above or covered was that most 24" or larger mirror ball motors I deal with have a slip mechanism which saves the motor's brushes from abuse when not powered up but spinnning to a stop. A slight mechanism between eye bolt hanging the mirror ball and shaft of the motor which allows the shaft of the mirror ball to slip to a natural stop when not powered up.

It should spin when not powered up.

The above mirror ball might keep spinning in no instant stop as it should naturally do in not destroyin the motor.
 

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