Diffusion frame

M

Mike H.

Member
I want to build my own diffusion frame and I'm looking for the right materials. I've built larger frames out of thick pvc tubing, but I haven't come across anything smaller. Pvc would be perfect because it's really light and you can take it apart for portablility.
Anyone know where I can get small pvc tubing ideal for a smaller diffusion frame? Any other materials come to mind? I need something that I can quickly disassemble and pack away.
Thanks,
 
24" x 36" would be a good place to start. But, it would be great to have a modular configuration where I could piece together a large 4'x4' by adding more tubing.
 
Square aluminum tubing will work though by the time you monkey around with a project like this, a Scrim Jim may be a easier, especially since you can buy scrims and reflectors to fit, and it is a modular system. In any event, here goes:

From a metals supply house, purchase 1" x 1/16" square aluminum tubing in the lengths you want for your frame. The 1/16" thickness will be plenty strong enough for a 4x4 frame. For the corner fittings or couplings, buy 1 1/4" x 1/8" thick. The 1" will slide inside of the larger tube. To make corner elbows, take two of the short lengths and have them tig welded at 90deg. The only thing to watch is if the 1 1/4" tube has a seam inside, you will need to file it flat so make the legs short. The tubing can be had seamless, but it will depend on the supplier stock. To finish, drill holes in the elbows and or couplings (accurately so they will be universal) and use sheet metal screws or better yet "quick pins" to hold the frame together.

One other suggestion for the tubing; if you order from a larger supply house like Alaska Copper and Brass, they will have 1" square tube with radiused corners which is nicer on the hands and fabric. See stock #490475. If you know the dimensions you need, they will cut to length and ship UPS. The 6063 alloy is easier to weld, the T-6 alloy is stronger. Either will work fine for what you are doing.

http://www.alaskancopper.com/pdf/al/square_tubing.pdf

http://www.alaskancopper.com/al_pt.php

If you do a good job of this, it will be better than a Scrim Jim, but will be some hassle to do.

Grant
 
If you still want PVC, Home Depot or Lowes both carry 1/2" schedule 20 and/or 40 pipe. I think you might have some issues with this size for anything over 36 X 36.

The other choice would be the 3/4" Schedule 40.

For versatility, cut in 12" lengths and use couplers and elbows for a press fit.

One trick a friend had to keep his frames together was threading a long enough piece of bungee type cord through it and then stretch it putting the frame under tension.
 
Thanks for the tips. I'll try Home Depot for the pvc tubes, and if that's a no go I'll look at a Scrim Jim. Matthews Road Rags look really nice too, but pricey :o
 
Mike H. said:
Thanks for the tips. I'll try Home Depot for the pvc tubes, and if that's a no go I'll look at a Scrim Jim. Matthews Road Rags look really nice too, but pricey :o
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Electrical conduit would be my first low budget choice. You can get it at Lowe's or The Home Depot along with corner fittings, etc.

PVC contains phthalates, lead, cadmium, and/or organotins, and manufacture or burning of it results in *dioxin* added to our ecosystem. It should be banned. Avoid.
 
What is your limitation in terms of space? Why don't you just buy a 3x3 frame instead of a 4x if that extra foot is the problem...it's really not even that expensive...
 
I've been a Westcott Scrim Jim user since they first came out - something like 18 years ago?? I still have my first set of frames and fabrics. I've gotten grannies at the fabric store to make me some special rags for it.

Really nice system for up to 6x6. After all those years, the velcro was coming loose from the frames, so I devoted a day with solvents and epoxy and a pop riveter to re-attach them. Another decade ahead!

Not the cheapest thing out there, but damn... well thought out gear that can be configured all sorts of ways. Find a good seamstress to make you fabrics and save some $$.
 
RyanT said:
What is your limitation in terms of space? Why don't you just buy a 3x3 frame instead of a 4x if that extra foot is the problem...it's really not even that expensive...
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It gets expensive when you need something portable that can fit into a side pocket. Road Rags cost about $500 for 2 frames, and 4 fabrics, only 1 of which is diffusion. If I can find the right building materials I could save about $400.
I'll try using electrical conduit as Chris suggested. If it works out I'll post some pictures.
 
This level of DIY is certainly admirable, and well done DIY? Clients really don't see it. That said, when you're doing paid gigs and trying to deliver bang for the buck, it's all about speed. Whatever system you devise for scrims & flags & reflectors of this nature, being able to set up, break down, pack, and rinse & repeat very quickly is the name of the game - you gotta design it in.
 
Chris Santucci said:
Electrical conduit would be my first low budget choice. You can get it at Lowe's or The Home Depot along with corner fittings, etc.

PVC contains phthalates, lead, cadmium, and/or organotins, and manufacture or burning of it results in *dioxin* added to our ecosystem. It should be banned. Avoid.
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I've used 1/2 metal conduit for 4x4 and 6x6 frames. It works great and you can build the whole frame for less than 10$.

EDIT:

I also went to the fabric store and bought a number of different white/translucent fabrics and a grommet kit. I had a friend sew up the fabrics into panels and then grommetted the edges so I could easily attach them to the frames.

White rip-stop, some kind of white lining and a translucent shower curtain are my favorites for the cheap solutions. All of this cost less than 50$
 
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Svart, what do you do to attach the frames to stands?

I have a nice quick-folding Manfrotto 6X but instead of buying a 12X I bought American Grip corners, ears and joints and bought some 6061 1" square Aluminum stock that I had cut to 6' lengths. I can build that frame as a 6X or 12X and it works great. I've only purchased commercial rags but there are some sewers around the country with decent prices, although nothing close to DIY.
 
ggrantly said:
+1 super clamps would be the ticket in square tube and plug directly onto a 5/8 spud.

Grant
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I think, Grant, that Mafers would be good with round tube but I think the spuds come off at a weird angle when you clamp square tube. :( Am I picturing that wrong?

Interesting that the clamps are going to cost more than the rest of the DIY frame and fabric.
 
Also, no matter how and what size you build, always make sure that it can be rigged safely.
 
julian said:
Also, no matter how and what size you build, always make sure that it can be rigged safely.
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That's right and wind is one of the big deal problems with frames. I just ran the numbers for a 6X6 and at 10 MPH the force on the frame is 10 lbs, but at 20 it's 37, at 30 it's 83 lbs and if you get a 40 MPH gust the force is 148 lbs! For a 12X multiply the numbers by 4.
 
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