#### Schniapereli

##### Active Member
What is the best way to make homemade gobos. I have heard of people making them out of aluminum foil (maybe just for a 3" spot) or I have heard of people making them out of the same material as the professionals. Do you just cut at with special knife. It looks tough to cut through...

Also, my uncle has a laser engraving machine that he uses to make trophies, ornaments, and other things. He can cut *PLEXIGLASS, and also make it different colors. Could this be used to make glass gobos? I don't know if it will be able to withstand the heat. I'm thinking if it we'd have to make a rectangular block to fit in the accessory slot, or would it still be withstandable if it were thin enough to put in the regualr gobo slot? (our ERS's are 750W Source Fours with 575W bulbs in them.)
If that is still hot, could we put a little one in just a baby spot?
I'm going to maybe take a little extra ornament and test it out inside the intense heat to see what would happen.
If it could work, than that would just be freakin' awesome at our school...

If any of you know about safely getting either the glass or metal to work well, then please grace me with your mighty wisdom.
I just want to make sure it won't ruin anything.

*=EDIT

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#### soundman

##### Well-Known Member
Basic gobos can be esily made out of disposable cookie sheets cut with a hobbie knife or a razor. Anythign with a lot of detail will be hard be hand, it is possible to make them using an acid bath. Technical Design Solutions for Theatre Vol 1 has a great write up of how to do it. In short you coat the gobo blanks (printers tin) with lacquer then scratch off where you want the acid to eat through.

I would think the lazer engraver would work as long as it could cut the metal completly.
No matter what you make the gobos out of in a source four they will get beat up by heat. After a few shows small deatil cuts will bend and be impossible to focus, so I wouldnt worry too much about heat hurting the metal. Just dont use cardboard, thats a bad idea as some other members found out.

#### Schniapereli

##### Active Member
The laser actually isn't strong enough to cut through metal, but it can cut through *PLEXIGLASS. I was wondering how thick *PLEXIGLASS has to be to not melt, if it can be used at all as a gobo. I probably didn't phrase that clearly...

But, that's a cool acid process. I don't think our school would let us ever use that method though... but it's something I want to try eventually...

I've been trying to find some good books too, so thanks for that suggestion. Our public library doesn't have a copy, but the a local college library has "Technical design solutions for theatre : the technical brief collection" by Sammler, Bronislaw J. (Bronislaw Joseph) if that is close to the same thing...

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#### soundman

##### Well-Known Member
I cant say if fiberglass would last.

The acid might be a bit risky if you presented it as a theatre poject but it might make for a great chemesty project...

That is the book I got the acid cutting process out of, Vol 1 page 9.

#### DarSax

##### Active Member
I'd think the fiberglass would last. We've used fiberglass as a lighting material in the past (don't ask. don't use.) and isn't it used to like, fireproof things? o.o

#### Schniapereli

##### Active Member
Sorry, I was misinformed. It is plexiglass, which is transparent, and he can add colors on it too, which is why I am so eager to see if it works...

Sorry for that mistake.

#### DarSax

##### Active Member

If you were using a selecon pacific, on the other hand...*sighs dreamily*

CB Mods

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#### kingfisher1

##### Active Member
PIE TIN!!!!!!!!!!!!!! its easy, cheap, looks good, you can leave the light on for as long as you want, stars don't have to be detailed, or IMO they don't. anyway good luck, just be really careful, the plastic will just melt al over then place. even if it doesn't its not a risk you hould take

#### Van

##### CBMod
CB Mods
pie tins, cookies sheet are the way to go!! i found that hair cutting scissors have a good point for detail work, (not too detailed) they dull fast, but i bet its worth it. the gobos lasted me tw entire days, with the light on full the entire time. if 48 strait hours of usage isn't enough well, that must be one long run...

also, if you are sucessful withslightly thinner aluminum you can use these hole punch thingies. they are for paper, for kids doing crafts, but i'd think they'd punch through aluminum. only pobllem is they only come in certain shapes, bears, airplanes, trains, etc, e.g.
http://cgi.ebay.com/BEAR-scrapbooki...ri-cutout_W0QQitemZ300055637722QQcmdZViewItem
You want really sharp scissor ? go borrow a pair from the costume shop, be sure not to tell them what your doing with them, They'll realy appreciate you from then forward...

Stay away from the plexi. As cool as it might be, trying to use a laser cutter to do all this neat stuff, your headed for heartbreak if you try to stick plexi in a ERS Period. It simply won't handle the heat. it will melt and realease toxic Cyano-acrylate fumes < yes cynanide based fumes > when it finally catches fire.

Put the laser cutter down and step away now, nobody gets hurt.

#### Schniapereli

##### Active Member
Well, now you excited me. I kind of want to put plexiglass in an old Shakespeare just to watch it burn...

I'll stay away from that idea. I just thought it might be cool, but oh well.

#### JRRichardson

##### Member
If you were using a selecon pacific, on the other hand...*sighs dreamily*[/QUOTE]

Even then it wold still melt - despite radiating heat out of the rear, the rest of the lamp still reaches considerable temp.

#### Dionysus

##### Well-Known Member
Im not a big fan of "pie tin" gobos, not sure what kind of pie tins your guys have but I find that the pie tin gobos (depending on fixture and duration etc) hardly worthwhile, needing to be replaced far too often.
I usually use sheetmetal, generally scraps from job sites I've worked on (have quite a stock lol). You can get some pretty thick stuff actually, and not all of it but the stuff I've really kept is STEEL so it handles the heat much better. With the right collection of tools its easy to form into rough shapes such as stars, or what have you. More difficult of course with more distinct or clear shapes.

At least the thinner materials including pie tin you can cut and shape with a pair of OLFA SCISSORS. Drill bits, dremel, tin snips, duct knife, electricians hole punch, uni-bit, etc... I've even made a "strange snow" gobo by hammering nails in to create rough not quite round shapes.

And yes don't ever use plastic for something that you're going to stuff in a fixture that will get exceedingly hot. It will just melt and make toxic gasses, and make you very sorry. "Glass" gobos are made from special glass for a reason.

99% of the time though, its just as nice to use a nice gobo from Rosco or Apollo or whoever.

#### Floobydust

##### Member
I've been told by others to look up a local company that makes trophies and awards because some of them have metal etching lasers that might take graphics input for their machines.
I haven't completed the research, but was gonna try to have them cut Rosco Matte Black Cinefoil.

Might be worth looking into.