Custom Gobos for LED Profiles

[TupeloTechie]

I have recently purchased two Strong Neeva LED Profile units and the ability to use less heat resistant gobo materials is intriguing.

It seems the consensus on trying to use a home printed transparency is that it really doesn't work. You never get a true black.

I know that Apollo and Rosco each sell a type of printed transparency gobo, that supposedly will produce a truer black, but it seems the price point just isn't competitive enough with traditional steel to warrant the switch.

Recently, simple plotter-cutter craft machines have gotten incredibly cheap, with smaller ones in the $100 range. Does anyone think a black vinyl cutout attached to a transparency film would withstand the heat from a 50w led source? If not, possibly there might be some sort of opaque black film that would hold up to the heat.

If this method works, creating a standard b/w gobo (with or without bridging) would cost less than a dollar, and you would be able to create as many as you want, in only a few minutes, with only a hundred dollar investment.

Any thoughts?

 

[RickR]

Beware of adhesives and heat.

 

[techieman33]

Your going to have to figure out the temperature of the light at the gobo slot. Once you have that you can start looking for materials that will withstand that temperature with no ill effect.

 

[TupeloTechie]

Beware of adhesives and heat.

This was my main concern.

I went ahead and ordered a small cutter, if nothing ends up working there's so many other uses for it. I'll post my results on Tuesday assuming UPS delivers on time.

 

[Les]

This was my main concern.

I went ahead and ordered a small cutter, if nothing ends up working there's so many other uses for it. I'll post my results on Tuesday assuming UPS delivers on time.

Use clear RTV silicone as your adhesive.

 

[microstar]

Sandwich two transparencies together for the black to block more light.

 

[TupeloTechie]

As expected UPS was a bit late, but I do have good news! I would rule the idea a complete success! YMMV, I have only tested this on a 50w Strong Neeva RGBA unit, and do not have access to any other units. As other manufacturers internal designs may vary, along with wattage, etc. I would not recommend trying this out unless you know the temperature at the gate, and how it changes over time. That being said, I just took the gamble with my experiment and got lucky.

To test the vinyl gobo idea I printed a "b" sized gobo design using simple thin text, with the majority of the gobo in black. The idea here was to test with the most resistance to light/heat as possible. The thin text was a bit difficult to "weed" and transfer to a blank transparency at first, but I think that will get easier once I get the hang of it. The "gobo" was then placed in a standard steel gobo holder and placed in the standard gobo slot. I then turned the fixture to full (R, G, B, & A @ FL) and observed the projected image every once in a while for a little over an hour and a half. There was no change in the projected image at all (looked just like steel,) there was no odors coming from the unit, and to my surprise, immediately after pulling out the gobo after over 1.5 hours, it was COOL to the touch.

My hypothesis is that the cooling fan for the led engine is blowing air into the gate, since it would be the largest opening, this air seems to be cooling the gobo. This might be a problem for the LED Profile designs that do not include a fan.