Cut your own case foam...

hoarp001

hoarp001

Veteran
So a while ago someone posted this thing on the steadicam forum about cutting your own case foam. I posted it again on here for us lot to look at.

Dunno if anyone tried it but its a LOT LOT harder than it looks. Lots of things to go wrong, if the wire is too thin it snaps, if its too thick it just melts the foam, if its too cold then it rips the foam, if its too hot it sets fire to the foam. Lots of stupid little problems that get in the way.

Anyway ive been experimenting for weeks and I found the solution. yay.

Anyway, just wondering, il make a video tutorial thing if anyone wants it, show the best kind of wire and power spply etc etc. Would anyone watch this if i made it?

Heres a photo of my first profile I cut. Its abit wonky, but the template was abit wonky. Abit of practace and more time spent making the template and im sure it will look prefect.

n506442569_1401626_8004464.jpg
 
That's be great, i'm starting to think the zacuto foam insert...is a littttle pricey for what it is, just cut foam..But then again, it is zacuto.
 
Yeah that would be terrific!! I'm in the market soon for a lens case and would love to be able to have some nice foam cut outs.
 
Yeah you use a heated wire but its a fine balance between setting fire to the foam and cutting it. Also if you use a wire thats too thin, it can snap, or bow forward which means the cut in the foam isnt where you think it is. Also when you turn it on, the wire expands so you need to build in a bigarse weight or spring to take the slack out.

Its more complicated than it looks.


A big sheet of eggbox foam just arrived, going to cut it into the lids of my cases now...
 
OK then.

You will need:
Nichrome wire (18 or 22SWG, you can get it from Rapid in the UK)

A beefy power supply. Im using a 12v car battery charger. You could use a fully charged car battery if you like.

Some thick high current wire and some beefy crocodile clips.

A weight of some kind, stage weight or a jimmy jib weight. Im using 10kg.

A big, flat desk or similar that you dont mind drilling a small hole in.

Two strong things of equal height to act as the side supports of the wire cutter

Something strong to go over the top, wood works fine.


Assemble all of the above into something that looksa bit like this:
n506442569_1396782_4792335.jpg


The weight hangs on the wire underneath to keep it tight. I will go over more detail in the video
 
For making the templates you need some kind of board, like MDF. Make sure it wont melt or burst into flames (MDF makes nasty smells but dosnt catch fire). Im using 6mm thick MDF.

To cut circular cutouts for lenses, you need to use holesaw cutters, from a DIY place. I have found for breechlock canon FD lenses, 63mm cutters are perfect. Most other twist on canon FDs are about 60mm in diameter, and the 63mm hole is too big. Unfortunatly they dont make 60mm cutters so you will ahve to cut a smaller one (57mm) and then sand the hole out with a flap wheel or similar tool to a line. Do it neatly.

All cutouts that will be cut out from the foam need to be cut out from the MDF. This is so you can run the wire inside the hole and guide it along the edge of the template. This ensures that you cannot slip and end up cutting into the foam that you want to keep.

To cut odd shaped holes, use a jigsaw, bandsaw, hack saw or a keyhole saw. Get the edges nice and sharp with files and sandpaper, and make sure that theres no burr or fur on the edge of the template.

You also need to drill some 2mm holes in the template to pin it down to the foam. I use small wire nails. dont use big ones ore the holes will be visable after yout ake the template off.


Once the tempalte is pinned down, stab a hole through the foam, thread the wire through, heat it up and QUICKLY zip round the edge of the hole. if you stop anywhere you will melt a big chasm in the foam, and it can catch fire. Once you have made the cut turn the wire off as quick as you can. wait for it to cool, unthread it and pull the plug out. You can then cut the plug to depth, stick it back in the hole and then put your lens or whatever in. Very neat.
 
hoarp001 Thanks for posting this. I have been wanting to get rid of the stupid tear out foam in my pelicans for many moons now. Great inspiration and idea there. I'm gonna do it when I get the chance.
 
"For making the templates you need some kind of board, like MDF. Make sure it wont melt or burst into flames (MDF makes nasty smells but dosnt catch fire). Im using 6mm thick MDF."


That can actually be very harmful to your lugs, may want to look into something like aluminum temps or even some sort of respirator. Any saw dust can be harmful without a mask, but medium density fiber can really hurt you. The smell you're taking in is the resin (formaldehyde) that they use/glue to keep the fiberboard together can be extremely bad to inhale. Especially know to cause cancer.

Just a heads up buddy. :)





Are you using the harder styrofoam or is that like the soft pluck foam material ?
 
Ive been cutting and working with MDF for years, not dead yet. I know of the health warnings though, they usualy say its fine if your in a well ventilated place. Because of the stink the foam makes when you cut it, i have the garage door open and so most of the fumes gets sucked out by the wind.

Its open cell, its like pick n pluck, but not pick n pluck. Solid and spongey.
 
Hot tip.
I always FREEZE my foam just before cutting. I can even cut with serrated steak knives using that method of prep!
 
cold will freeze anything, not just moisture, freezing any material will slow down the molecules , just as heating speeds them up. slower molecules means harder substance, it may not make the foam rock hard, or ice hard, but I can see how it would make it easier to cut.
 
Good tip on the freezing Zephyr - had to drill some foam like that once. Soaking it in a bit of water then freezing will make it really rigid, although something about melting ice and a hot foam cutter scares the **** out of me. And actually the foam is already "frozen", and reducing the temperature wont slow down the molecules at all. They're already in formation and arent going anywhere. (technically they can vibrate but that doesnt have much to do with this) Reducing the temperature will shorten the atomic bonds though resulting in a slightly smaller more compact structure which enhances the rigidity, reduces the pliability, and increases the brittleness. Same reason plastic levers break off in the cold and can be reshaped when heated without melting the plastic. Jason's description applies to behavior of molecules in a liquid.
 
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