New DIY Kino plans

[tigeba]

I am working up some new plans for Kino Diva 400 type lights. Most of the designs use metal construction but I am going for something lighter.

http://www.kinoflo.com/new/Diva-Lite/hero.jpg


My question to anyone who has actually used them is this: How do the barndoor hinges work? From the pictures it appears there is a metal rail that is held on the ends, but it is impossilble for me to determine if these are just fixed pieces of metal, or hinged, or double hinged.

My guess is that there is one hinge and that the curved shape of the barndoor is fixed, but I have never used one so I don't know..

Thanks for any input.

[MattinSTL]

Nope... but good guess. The material is like Coroplast... that I'm sure you knew. You have to be aware that there are several types of corrugated plastic that appears the same... some of it will get super-soft in sunlight... I mean it's so bad that it will wear out WAY too soon just from being in a hot car several times. That's the kind that I gave away as temporary barndoors with my lights and that's why I specified that they are temporary.

The corrugated plastic of the Kinos is a much stiffer plastic that's more durable and probably UV resistant. I've seen polycarbonate in this form, so that would probably be the best... if you can find it in black. I've seen it in a dark smoke that's a little translucent, but I haven't seen black from a local supplier yet.

Look up "plastics" in the yellow pages... if you're in a major metropolitan area you will have a lot of plastics wholesalers and one of them will have something that works.

Okay... sorry to take too long to get to the point... the Diva ends are "wrapped" with a plastic that goes around the open channels of the "coroplast"... with space left to tunnel a gooseneck through... here, it does THIS> (_) around the outter edge.

Within the channel that is formed like that there is a flexible "snake"... have you ever used one of the bendable things for a french flag? It's similar to that... you can look to the automotive industry to find the material cheaper then butchering Manfrotto pieces... it's like a tightly spiraled metal that is resistant to bend, but holds various bends. This "snake" runs through the channel made by the plastic (or metal) that's "folded" around the ends... and so you can open the light and it holds (not perfectly, but it DOES hold) in a given position... Opening a Diva is like unfolding aluminum foil... it's not a precision thing AT ALL... and when you close the light back up you have to kind of "encourage" it to fold all the way back down.

Actually it was playing with Kino fixtures that first convinced me not to spend a fortune buying them... they are not a sight to behold... in my opinion they look just a little better then some DIY project... at least until you get up in the range of the ParaBeam.

These are sometimes called "flexible arms".

http://www.bhphotovideo.com/images/items/233115.jpg

They are also sometimes called "flexible-neck" or gooseneck... when I spot a cheap source I'll post back... so far nothing. The Kino one is about 1/4" in diameter and it runs the entire open width at both ends... so it's about 18-24" long.

[tigeba]

RE: The plastic. Thanks for confirming my thoughts there. From the few closeup shots I could find it sure looked like coroplast. I scored 2 4X8 sheets of black coroplast from a sign shop. The material I got is completely opaque, and was about 20$ a sheet. This stuff is made for outdoor signs, so I have to guess that it is at least somewhat UV resistant. I can't really tell at this point if it will be durable enough or not. The plastic signs you see stuck everywhere sure seem to last for an eternity... It is obviously very floppy in the large flat sheets, but I think cut down it will be ok.

Big thanks for the info on how the doors work. I have a bunch of that stuff (gooseneck) for various applications in the recording studio. I will see if I can obtain a bit smaller diameter stuff for this application. Off of the top of my head, I think there is some flexible metal electrical conduit that might work, but it might be too stiff. At least it would be cheap. I would not have thought it was gooseneck, but I guess considering how light the doors are it should be enough.

[Anders Holck]

Most of the bank systems from kinoflo, just use 5mm wire in the ends and not the gooseneck. Don't know the exact material.

[MattinSTL]

That corrugated plastic comes in all materials and all thicknesses. You need to talk to a plastics wholesaler and not a sign shop. I bought a TON of that stuff! If you get it in the 1/4" thickness and get $150+ worth then it's only $8 sheet!

BUT for the tougher material? I haven't found a good source on that yet... and it will be much more... probably more in line with $20 sheet... the Diva is made from about 1/4" thick to 3/8" thick material. It's thicker then the 1/4" coroplast that I bought... but not way thicker.

It's one continuous piece so the material has to be durable enough to be folded and unfolded hundreds of times...

The best way to tell with your current black coroplast is to put a piece out in the direct sun and see if it starts to develop stress lines (like really small light lines) after 15 minutes... that will tell you not to put too much into it.

[LowDown]

For the hinges you could try using "armature wire", you can find it in various thicknesses at art supply shops. It is used for sculpting.
http://www.dickblick.com/zz334/00a/
Shane.

[TeamJoeDawn]

Maybe to solve some of your "welding" problems.. I'd suggest some kind of epoxy (or jb-weld) and reinforced with pop-rivets?

J

[tigeba]

For the hinges you could try using "armature wire", you can find it in various thicknesses at art supply shops. It is used for sculpting.
http://www.dickblick.com/zz334/00a/
Shane.

Thanks for the idea, but I think aluminum wire would probably not be well suited for this particular application. It fatigues very quickly after multiple bends.

[tigeba]

Maybe to solve some of your "welding" problems.. I'd suggest some kind of epoxy (or jb-weld) and reinforced with pop-rivets?

J


I think that would work. I was planning on using some black naugahyde-ish fabric I have around and either pop rivets or grommets.

[MattinSTL]

They make rivets with wide "shoulders" and you can also use washers in combination with rivets to distribute pressure. Kino fixtures are usually rivetted that way. (from what I remember recently) Rivetting fasteners are the least of your worries.