Installing a gobo in a holder

[howartp]

Hi,

 

I've got two size B gobos and a size B gobo holder for one of our luminaires - off the top of my head it's a Strand Quartet but I may be remembering wrong.

 

I know about putting the gobo in upside down and back-to-front, that's fine.

 

What I'm completely missing is how to install something of diameter 'x' into lugs designed to hold that same diameter circle.

 

Please see photos:

 

http://web.southcrav...rg/IMG_0990.JPG

 

http://web.southcrav...rg/IMG_0991.JPG

 

http://web.southcrav...rg/IMG_0992.JPG

 

The first gobo I've had for a while is metal, so I managed to wedge it into two lugs and install it, but the new gobo is glass which is thicker so won't fit in the gobo slot with it wedged at that angle.

 

Any help?

 

Peter

 

 

 

[gyro_gearloose]

You'll need a gobo holder that is specifically made to hold glass gobos.

[maeterlinck]

As above. In a snip you can cut off the top tab of a metal gobo holder and use some black tack to hold in place.

[howartp]

But how do either of these help me with the metal gobo in the picture?

 

Peter

 

 

 

[Glyn Edwards]

Metal gobos generally have enough "spring" in them that you can sit it in the bottom two lugs and the flex it to sit behind the third. As you've already discovered, you can't do that with glass, so you need a special holder. These normally have 3 lugs again, but are positioned differently to allow the glass gobo to "rotate" in all three.

This PAGE shows the physical difference. The glass holder is on the left and the metal on the right.

 

HTH

[Marineboy63]

As above, glass gobos have special holders.

[howartp]

But how do either of these help me with the metal gobo in the picture?

 

Peter

 

 

Or is that not metal either?

 

 

 

 

 

 

 

[gyro_gearloose]

....and use some black tack to hold in place.

Which is fine right up until the moment when the black tack fails due to the heat melting the adhesive. Then the Gobo falls forward, gets trapped in the gobo slot, and can't easily be pulled out again. Use a proper Gobo holder.

[timsabre]

But how do either of these help me with the metal gobo in the picture?

 

Peter

 

 

Or is that not metal either?

 

 

The gobo pictured looks like a glass gobo. A metal gobo is very thin and bendy and has actual holes in it where the light goes through, so you can't do (for example) full circles or the inside of your shield design without having tags between the two parts to stop it all falling apart.

[gyro_gearloose]

But how do either of these help me with the metal gobo in the picture?

Thats a metal gobo? Really?? Looks like glass to me, as the shield detail is very fine and doesn't appear to have any support structures. The easy way to tell the difference is that only glass gobos don't bend :D

 

Edit: Must learn to type faster :D

[Shez]

In a snip you can cut off the top tab of a metal gobo holder

You can also bend it out of the way but if you do that more than a few times, it'll come off of its own accord anyway.

 

When using glass gobo holders, be wary of tilting it when trying to fit it in its slot as the gobo can roll out very easily. Don't ask me how I know that The glass they're made from seems to be pretty tough though.

[howartp]

Edit: Must learn to type faster :D

 

Yeah, I'm having that problem this morning :)

 

The thread index said '2 replies' when I hit reply, but there were 4 by the time I hit ok!

 

Thanks everyone, that explains why I've been having such a bad time trying to get it in; I'm actually going to have to re-order the new gobo cos it's got a nice big crack across it from my attempts :(

 

I'm on the phone to Rosco now.

 

Peter

 

 

 

 

 

[gyro_gearloose]

I'm actually going to have to re-order the new gobo cos it's got a nice big crack across it from my attempts :(

Clearly not a metal gobo then.....

[PeterT]

I'd also be wary of putting it in front of a Strand Quartet as it's likely to crack due to the heat. You need an axial spot (e.g. Source 4/ SL etc.)

[vinntec]

I'd also be wary of putting it in front of a Strand Quartet as it's likely to crack due to the heat. You need an axial spot (e.g. Source 4/ SL etc.)

I have used glass gobos in our fleet of Strand Preludes and they were fine (also in SL) - but we religiously had a "preheat" cycle when power was first turned on with lamp on low intensity (which is as advised by Rosco) so they were warmed before first use full on each performance until the preset. Never had a problem other than our logo changing so they became obsolete!