Color Scroller Fan Speed Safety

[calkew5]

I feel like I've made a good faith effort to see if this question's been answered already and I can't find it. So here goes:

How safe is it to slow down the fan speed on a scroller?

Here's why I ask: I've got five SmartColors in a pretty small space - the stage is 39' wide including wings - and I really need to use them because I don't have enough instruments to get the kind of variety I want otherwise. The space only has 46 working dimmers.

Trouble is, the grid height is 16' above the stage, and only about 18' over the audience, and with the fans on the scrollers at their normal operating speed, even when they're not doing anything, they are obnoxiously loud. I don't want to use them if they're going to be a gigantic distraction.

So I know from the operating manual that you can set fan speed by dipswitches, or set fan speed to DMX control. What are the consequences of not running the fans all the time? Does the motor constantly generate heat that will destroy the gel scroll even if it's not moving? What kind of compromise can I make? What's the potential for damage to the equipment?

To make it clear, I'm not asking about the movement of the scroll, which I know I can just save for the louder parts of the show, or set to slow speed. I'm asking about that stupid whirring fan - make that five stupid whirring fans - making a racket above everyone's heads all the time.

Anyone else in a small space that has advice on non-distracting scroller use?

 

[sk8rsdad]

It depends on the instrument you are using as a light source, how long it will be on, and your expectations about the life of your gel string. We run Chroma-Qs with the fans at half speed. They are audibly unnoticable and the fan noise is dramatically less than when running at full (factory default). I expect we could turn the fans off completely with SourceFour instruments and experience no difficulties at all with the electronics, although I would be inclined to stick a heat shield in to boost gel life.

What does the manufacturer's website have to say about it?

 

[calkew5]

Well, let me clarify the question.

What is the fan for? What is it's purpose? Is it there just for the protection of the gel string from the lighting instrument, or from additional heat from the motor inside the scroller? If it's just to protect from the heat of the light, then you could just turn them off and be dandy, at least in my case, since I'm using S4's (not to mention the gel shield that comes in SmartColors). But I don't know if that's true.

 

[Les]

The fan is probably there to cool the gel string, electronics, or both (from the heat of the instrument). I doubt the motor inside generates any substantial heat.

 

[sk8rsdad]

Well, let me clarify the question.

What is the fan for? What is it's purpose?

Inferring from the user manual from Apollo's website:

The fan speed is continuously variable in response to the console fader. Fader position at 0% is fan at high speed. Fader position at 100% is fan stopped. Use extreme care when using this setting to avoid damage to the gel string.

The manual does not mention anything about protecting the electronics, from which I conclude that its primary purpose is to protect the gel string from premature failure due to heat from the lighting instrument.

 

[BCG45]

This takes a little work, but here is what I do...

I program the fan speed into every cue to select a speed depending on the color to be used. If the light is off, so is the fan. I pick a speed depending on the gel and the intensity for when the light is on. Light gels like the no color straw need little cooling because they don't absorb much of the light, but highly saturated gels like sky blue or kelly green need a lot more cooling, so I boost the speed when using one of them. My goal is to run the fan at the lowest speed I think I can get away with. So far, I haven't melted any of the gels in the string.

If you think those scroller fans are noisy, at my theatre we have an Altman 1000W spot that sits right beside the sound mixing board and is only about a foot above the heads of the people in the back row. The sound guys have a fit when that puppy is fired up and I'm sure the people just below it are annoyed as well.

 

[midgetgreen11]

1000Q fans are GOD awful. We have a 778 seat house and you can hear it from the stage when its on behind the back row.

 

[Kelite]

I program the fan speed into every cue to select a speed depending on the color to be used. If the light is off, so is the fan. I pick a speed depending on the gel and the intensity for when the light is on. Light gels like the no color straw need little cooling because they don't absorb much of the light, but highly saturated gels like sky blue or kelly green need a lot more cooling, so I boost the speed when using one of them. My goal is to run the fan at the lowest speed I think I can get away with. So far, I haven't melted any of the gels in the string.

Good day calkew5, and thanks for posting this question. Had I not been on vacation for three of the past four weeks I would have been more responsive and posted sooner!

The procedure mentioned by BCG45 is certainly worth considering, as light gel colors aren't affected by the IR as much as the darker transmissions. The Apollo Gel Shield adds an additional layer of protection, especially when operating the Smart Colors at lower fan speeds.

I must ask- are these color scrollers several years old, and have they been powered up for a majority of their installed lives? (ie- fans powered by the PSU when lights have been powered down.)


Looking forward to assisting you,

 

[seanandkate]

I keep my Chroma Qs set to the lowest fan speed with a Rosco heat shield and have never had a problem with the string buckling from heat (can't say that BEFORE the heat shield . . )

 

[DCATTechie]

I ran 6 SmartColors at the lowest fan speed setting for a 2.5 hour show (3 day run) (30 mins. of which the fans were completely off) and ran into no problems. During tear-down I brought all of the scrollers up to the booth and inspected each frame carefully for damage and found none, however I did replace the heat-shield on each scroller after the show closed.

 

[Footer]

I really don't like the idea of a scroller fan being on DMX control. I could see doing this for an theme park type situation where the gear is put up and used for years, but not for strait theatre. The thought of having to actually think about what my fans would be doing while programing would drive me up the wall. Also, they would be forgotten guaranteed. Now, you you would patch the fan channel to the intensity channel of the light, that could work I guess. For S4's I have always set the apollo fans on low. If I am using a par64 or any 1k fixture, it goes on high.

 

[Kelite]

During tear-down I brought all of the scrollers up to the booth and inspected each frame carefully for damage and found none, however I did replace the heat-shield on each scroller after the show closed.

Thanks for the tip DCATTechie, but why did you replace the Gel Shield? Was it several years old and 'cooked'?

The IR and UV reflecting Gel Shield has a pretty long life, so you've got me wondering...

 

[Brownlight]

Hey
Ok its very smiple if the light is on the fan is on. When the light is off turn the fan off via DMX. I you dont use your fan to cool the gel you will burn through the gel. What fixture are you using on the scrollers? Without the fan running your gel well break down faster and you will need to replace it sooner.

 

[DCATTechie]

...but why did you replace the Gel Shield? Was it several years old and 'cooked'?

The IR and UV reflecting Gel Shield has a pretty long life, so you've got me wondering...

Yes, 4 of the scrollers were aged (not sure on the manufacturer date as they were bought used) so the gel shield was getting questionable and I thought I would play it safe by replacing it.

The other two scrollers had been on tight irised-down (sp?) fixtures. There was no noticeable sign of damage, nor was there a burn hole/mark, but I had spare gel shield so, again, I thought I would play it safe by replacing it in case there was something I had missed or overlooked.

Speaking of burn holes/marks, does gel shield burn? Rather, is it possible for the gel shield to lose its IR and UV reflecting effectiveness? Seeing how it is clear, I don't know how to tell if it was damaged other than by there being a hole in it.

 

[NevilleLighting]

BCG45,
That sounds like a pretty reasonable and smart method to protect the gel. Hopefully it helps the electronics too. In my own experience I find that fan noise is often adjusted to by an audience. It's changes in the noise that will almost imperceptibly be noticed.

 

[Kelite]

Yes, 4 of the scrollers were aged (not sure on the manufacturer date as they were bought used) so the gel shield was getting questionable and I thought I would play it safe by replacing it.

Good thinking- playing it safe is always a good thing.

Speaking of burn holes/marks, does gel shield burn? Rather, is it possible for the gel shield to lose its IR and UV reflecting effectiveness? Seeing how it is clear, I don't know how to tell if it was damaged other than by there being a hole in it.

The Apollo Gel Shield, as you already know, is a pretty thick material. As a matter of fact, it is almost as thick as Apollo's steel gobos- 7 mil. This heavy polyester has been sputter-coated with a several layers of thin film protectants in the same fashion dichroic filters are made. Oils from one's fingerprints will permeate the thin film surface, so keeping mitts off the material allows longest life.

If Apollo Gel Shield becomes hazy, the coatings have begun to discolor due to heat. As we know, heat (IR transmission) affects most everything under the sun, just because God made it (the heat) that way. We have seen Smart Color scrollers used in touring and permanent installations that retain their protective qualities years after their initial use, so as long as it is clear- you've got great heat protection.

Thanks again for clarifying your use and replacement motives.

The original poster had mentioned fan noise, which points to a worn fan. If the scrollers are on 24/7/365, as is sometimes the case with HOW installations, then they are toasted and need replaced. I was hoping the OP would have replied with more info, but not as of yet...