# LED Pulley System



## applemacguy91 (Feb 2, 2011)

Hi,

First, let me explain what I want to do. I am planning on hanging 8 LED Par fixtures individually from two sections of truss using aircraft cable. Second, I am planning on running the aircraft cable through a pulley system to where they can be raised and lowered during the show for different scenes. 

Now my question is, is it possible to purchase or build a motor system that can handle all 8 LED's? For instance, is it possible to have each of the 8 LED's on a dedicated motor? I want to have control of the motors via my lighting desk, so that I can program the different positions in cues. Whatever protocol is necessary, I'm fine with it. I'm just looking for a solution to this without costing me my firstborn child.

If I can't find a motor system, I will simply pair them by twos and use manual winches.

Thanks,
Kyle


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## Footer (Feb 2, 2011)

Your going to get a bunch of responses you are not going to like. 

You can get a motor system to do it. However, 8 winches that are rated for overhead lifting, have encoders, a motor controller, and a DMX interface for that motor controller are going to cost in 10x as much as your LED pars. 

As far as hand winches... 
Yes, you can do that to, however those winches that are rated for overhead lifting are also costly. Boat/bumper winches are not designed for overhead lifting. CM makes a winch designed for this: Meteor

Added to that, you are going to have to find a way to deal with cable spin and cable management. With one point, that is also going to be a challenge. 

Once again, it can be done. However, it can't be done on the cheap without a huge amount of risk. Do it right or don't do it at all.


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## soundman (Feb 2, 2011)

Sounds like you want  Speedwire by upstaging. Its not too complex its a drum turned by a motor controlled by a variable frequency drive unit with all necessary safety precautions and DMX control.


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## TheatrePros (Feb 3, 2011)

I have seen it done, but all with custom units, you can certainly (with enough throw) keep working each pair of cables down on clews to get it to one line, but remember the more pulleys involved the more stress and thus the higher rating you need on each motor. I have done where I can operation 4 individual drums with one motor with a Q Drive system that was developed by Rich Bynum at Hawkeye Studios in Chicago...they have since gone out of business, but I know he still does automation consulting. PM me and I will try to hunt down his contact info for you.


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## derekleffew (Feb 3, 2011)

TheatrePros said:


> ...keep working each pair of cables down on clues to get it to one line, ...


Get a clew!


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## len (Feb 3, 2011)

Can you give more detail on your project? My guess is using a speedwire system would work (never heard of it before) but I'm also guessing it's way outside your budget.


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## shiben (Feb 3, 2011)

How much money you got? Speedwire seems to be the solution, but I cant see that going for under 1k a unit. Also, wont it twist? You probably want multiple lift lines per unit all the way up to the truss? Also, how different are the positions gonna be? If they are all in a repeatable pattern, you can always mount them via dead hangs from a batten and just spike it in different places for different scenes, or even on 2 or 3 battens for more variation. This to me sounds a lot simpler and cheaper, because thats a max of 3 guys on the rail pulling, rather than a bunch of electronic stuff that can (and probably will) break or stop working.


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## mstaylor (Feb 5, 2011)

Also, rarely is it a good idea to run motors via DMX or other from your FOH desk. You can't see potential hangups, but I'm just overly cautious about that kind of thing.


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## kicknargel (Feb 7, 2011)

I can see lots of potential problems running motors from a lighting console. For example, sometime if I'm searching for an address of a light or scroller, I'll quickly flip addresses (dimmer numbers) to full until I find the one I need. Not something you want to do to a motor accidentally. I'm sure there are safe setups where the desk is driving another control device with appropriate precautions, or a show control system is driving both controllers.


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## SHARYNF (Feb 8, 2011)

do you need to raise and lower them OR can you use a pan and tilt system. It is possible to get Pan and tilt systems that were use in cctv system pretty cheap these days. You could mount the led par to the PT and then you could get a controller that you could use for this

Pelco made a 24 volt system, and an inexpensive joy stick controller

Pelco Pan and Tilt PT280-24P - eBay (item 180622706135 end time Feb-10-11 08:29:23 PST)
and item number 230580919598

Just a thought 

Sharyn


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## MPowers (Feb 9, 2011)

As the OP has not responded to questions, I'm not sure if posting will help, but, here goes.

More info please if we are going to help.
What is the weight of the fixtures?
What is the desired travel distance?
Is the travel distance the same each time the unit moves?
Is the travel distance the same for each unit?
What is the speed of travel desired?
Is variable speed needed?


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## gafftaper (Feb 10, 2011)

mstaylor said:


> Also, rarely is it a good idea to run motors via DMX or other from your FOH desk. You can't see potential hangups, but I'm just overly cautious about that kind of thing.


 
You aren't being overly cautions Michael. With DMX you have no bidirectional communication and no error checking. Therefore, DMX should not be used for overhead lifting, motion control, or pyro. When should those winches stop or are they going too fast? The DMX console has no idea because it gets no feedback. One little burp in the stream of data and pyro goes off or things start moving. Don't do it. This is why there are specially designed systems for motion control and pyro.


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