Running an electric motor off of stagepin.

SketchyCroftPpl

Active Member
Joined
Dec 28, 2004
Location
Near Worcester, Mass
Hello all. This post is attempting to avoid me from creating a what went wrong post in a few months. We're doing a show where the entire thing takes place on a train. And we've decided (among the student techs) that we would like to have some type of scenery going past the windows and we don't want to have to turn it by hand for an hour and a half show cuase that would just be annoying. So I'm looking for some type of motor that can have some way to be hung by a baton and will run of of stagepin. I think if need be we have a stagepin - edison conversion cable (actually a few of them) but I beleive that all that avoids is the physical connection and has nothing to do with the volts and amps and such. So if anyone has any ideas as to how to go about this. Or even any specific motors that would work for this purpose that would be amazing.

~Nick
 

kingfisher1

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Joined
Jul 14, 2005
How fast is this train supposed to be going, i.e. what is the rpm requirements. also how much torque will be needed?
 

jumpjet

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Jun 2, 2005
Location
Chicago Suburbs
Typically motors do not play well with dimmable circuits. Some of my students learned this first hand by burning out a large Mars light motor by running it at various voltages for a year.

That being said, if you can find a motor that you don't really care about, you should be able to get away with it for the run of a single show. I think that they make motors that can run at different speeds by um.. help me out here guys.. incomplete phase? Where you don't get all of the AC wave, only parts of it. Feh, that is the end of my motor knowledge.
 

SketchyCroftPpl

Active Member
Joined
Dec 28, 2004
Location
Near Worcester, Mass
Its still a very great help. All I was working off of was mroe of the idea if you have a little hobby motor, and you put a bigger battery on it, it goes faster. The only problem there is that if you chance the batter you change the voltage and the amps. But one of the two will chance it.
 

BillESC

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Joined
Aug 29, 2005
Location
Kilmarnock, VA
Vue More MFG. makes a variable speed ceiling turner for the display industry. About $ 200.00. You simply supply it with 110v and vary the speed with a provided remote control.

From this device you could hang a cylinder that would operate as the drive for the endless scenic loop, at the other end you'd need another cylinder to act as an idler pully.
 

kingfisher1

Active Member
Joined
Jul 14, 2005
if need to dim the motor you can't use the sine wave dimmers but you can use the dimmers that we have in our houses. (i think the are resistence dimmers, correct me if im wrong.) I was thinkiing if you know anyone who owns a lathe, yuou could borrow that motor, only thing is you might end up with a train that could break the sound barrier
 

ship

Senior Team Emeritus
Premium Member
Joined
Mar 29, 2003
Location
Illinois
I think we are all jumpin to a conclusion that the drop box/batten stage pin outputs having a direct connection to the dimmer and specifically to a dimmer. It's possible that they are directly linked to the dimmers but not in a good system unless dimmer per circuit.

The stage pin 2P&G plug is a plug that's rated for 20 Amps at 125v or 10 Amps 250v. It does not care what it's running just as an Edison plug does not care if it is plugging in a table lamp or a grinder.

More it's a question of given this motor of some type which is plugged into this outlet, how it's getting it's power. If you are able to hot patch certain circuits such as for your work lights or specials, fine, run it off the hot patch and in general plug nor circuit will notice if it's a motor or a lamp run off it. If your dimmers have removable dimmer cards, switch out a dimmer card for a non-dim or relay card and you thus have power without messing with running the motor thru the dimmer.

If you have no ability to patch what circuits above the stage go to what dimmer or hot patch circuit, than getting a dimmer that won't mind a dimmer run at full such as the Vue Mor brand in something custom for your application should work fine.

Often with a hot patch, you won't be able to control it off the light board - sometimes dependant upon the patch panel you can. Othewise as said, if your dimmers have removable dimmer cards, dependant upon the brand it's possible to remove the dimmer and install a relay or switching card so as to power up non-lighting equipment by way of the dimmer system and DMX or what ever control language the dimmers speak.

Learning more about how your system works will be a requirement before you get too far however. But a stage pin plug is just a plug, it don't care what type of load is powered off it. Most of my mirror ball motors for instance have stage pin plugs on them.
 

kingfisher1

Active Member
Joined
Jul 14, 2005
just to clarify something. you can't run most motors of the dimmers we use on our lights because the constant on/off frys the whatever makes the motor go. Is this correst?
 

BillESC

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Joined
Aug 29, 2005
Location
Kilmarnock, VA
To clear things up...

Motors that operate on 110v to 120v can be connected to a dimmer circuit for power if the dimmers output is within the same range.

That said, one should use the "dimmer" as a non-dim circuit. It should either be full on or full off, anywhere inbetween is where problems may occur.

The only dimmer which can operate an AC motor and vary the speed is called a Variac. I haven't seen one of those in use since my old off Broadway days.
 

ship

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Premium Member
Joined
Mar 29, 2003
Location
Illinois
In getting more specific about the type of motor that does not get destroyed by dimmer chopping, it's what type of motor? I'm forgetting which type is more able to cope with running off a dimmer power supply.

Don't some dimmers also have non-dim mode?
 

BillESC

Well-Known Member
Joined
Aug 29, 2005
Location
Kilmarnock, VA
You know, it seems to me there is a much easier way to accomplish the desired effect than using an endless loop of scenery.

Using a digital movie camera, shoot the passing scenery from a moving car. This can be projected onto an RP screen for a great effect.

You could even calculate various speeds for the trains trip if so desired.
 

blsmn

Member
Joined
Apr 29, 2004
Location
Wisconsin
BillESC said:
You know, it seems to me there is a much easier way to accomplish the desired effect than using an endless loop of scenery.

Using a digital movie camera, shoot the passing scenery from a moving car. This can be projected onto an RP screen for a great effect.

You could even calculate various speeds for the trains trip if so desired.
That's what I would go for - only issue I could see is how many windows there are on the train, how close together they are, and how many could be covered by one projector. If two projectors would be needed, you'd probably have to use two digital cameras in a car - one in the front seat and one in the back to get the scenery change perspective correct. That actually would be a fun thing to put together :)