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Carlos E. Martinez April 3rd, 2005 04:55 PM

Strictly DIY fluorescent
 
This is one project that might be interesting to those that are willing, as I am, to build a cheap fluo head using 55 watt Biax 4-pin lamps.

Those lamps come in different types, and I am still investigating who is manufacturing. As far as I know, GE and Osram do make them. Lowel uses the Osram types on their Fluotec and Caselite types.

This is the first thing everyone interested in this project should do: see if any of those lamps are available in your country or city.

There are different wattages, color temperatures and CRI you should find. All can be used, but you should know what you get.

Wattage can be 36w and 55w. Color temperature can be 3000K, 3200K and 5600K, though you may find aquarium types that are 9325K with a low CRI (67) and are not good for us. CRI should be as high as possible, and you should find close to CRI 90 types. The closer to 100 the better.

Color temp can be corrected a bit, using gelatines or color celophane, but it will rob a great part of your light.

Next you should try to find what ready-made packages are being made for those 4-pin lamps. Application to look for should be compact, if possible, like a metal or plastic box.

The ones I found can hold one or two lamps, are metal types about 5cm thick. They have a frosted glass that can be used or not, held by a screw.

What a friend of mine suggested was finding a way to pile up up to four of these boxes, to get up to 440w from a single block.

At first I thought of screwing or locking them onto each other, but now I think I can use some kind of U-shaped aluminum profile that might allow sliding the blocks through a removable top of some kind, even if that might not be essential, as a screw of some kind or a wedge might hold the blocks in place.

Then I should provide an U-shaped flat bar, to be screwed on each side of the U profile and screwed on to a tripod.

Independent switches should be provided for each lamp.

This is the basic idea and where I got till now on my plans. I would be interested in having some feedback or ideas to improve on this project. Perhaps someone has already worked on a similar concept and might have some thoughts on what will work and what will not.


Carlos

John Sandel April 3rd, 2005 06:00 PM

Carlos, have you got any photos you can share?

Carlos E. Martinez April 3rd, 2005 07:07 PM

<<<-- Originally posted by John Sandel : have you got any photos you can share? -->>>


Not yet, but I should have this week.


Carlos

John Sandel April 3rd, 2005 08:17 PM

Please keep us posted. Sounds interesting.

Kyle Ringin April 3rd, 2005 09:01 PM

Yeah, Good job.
Can't wait for those photos...

Mike Cook April 4th, 2005 08:55 AM

I checked with a local metal shop and a nice box can be fabricated out of aluminum or steel for about $70. The only part I need to figure out is the reflector. Polished surface stuff seems hard to find.

M

Carlos E. Martinez April 4th, 2005 09:07 AM

<<<-- Originally posted by Mike Cook : I checked with a local metal shop and a nice box can be fabricated out of aluminum or steel for about $70. The only part I need to figure out is the reflector. Polished surface stuff seems hard to find.
-->>>

The packages for two-lamps that I mentioned already have reflectors. Even if they didn't, gluing aluminum sheet from cooking roll types should be easy.

The good thing when a reflector is properly done is the light concentration it provides.

Carlos E. Martinez April 6th, 2005 06:54 PM

First move
 
Ok. Today I bought the first module parts.

The holding box, designed to be held from the ceiling, is a sheet metal type, painted white.

It's 28" long X 6 1/3" wide X 2" thick.

The one I found has a protection/diffusion glass that you can unscrew. This you should do for this application, as the glass is quite heavy, thin and long. If you do locations with it, I don't think it will last long. So let's get rid of it.

After you eliminate the glass plate, the box, even with the ballasts inside, is quite light. It might be possible to find a box with no glass, so you won't pay for something you won't be using. This I will try to find out too.

One of the reasons for the box being light is that it has no back plate, as it was designed to be clamped to the ceiling. A back plate of some kind should be provided, something which we should take care later on if we are going to pile several modules.

Behind the lamps there's a polished flat aluminium reflector, so most of the light won't be wasted.

A pleasant surprise was to discover that the ballasts are bi-volt types, working from 127v or 220v AC. These ballasts are high-frequency flicker-free types, feeding just one lamp each.

There might be different ballast brands available, and that deserves some further investigation. One guy at a lamp shop once told me there were better ones, but I can't remember the brand. As the ballasts go inside the steel box, there shouldn't be any RFI emissions coming from them.

The lamps have no specified voltage, only saying they are 55W types and the color temp. In my case they are 3200 K.

The lamp box has two 4-pin lamp sockets inside and two lamp holders close to the other end. This is very good as the lamp then will not move.

Money spent until now: about $80. This might be a bit less if you live in the US or Europe, as many of these parts are imported here.

The next step would be to find an U-shaped aluminum profile that will allow sliding in the modules horizontally.

I will try to put some photos here when I get further on.


Carlos

Graham Bernard April 6th, 2005 10:54 PM

FL-500 Imager
 
Carlos - well done!

Here in the UK I haven't been a slouch either . .. I've tracked down this item - still need to find a supplier.

* 30cm x 30cm x 7cm

* 3 x 55 watt (?)

* 3 lamp switchable light ganging

i) Middle one
ii) Outer 2
iii) All 3

* Barn doors

* Edge support clamp (?)

* Option to purchase a pack of filters

But looking real close it would not seem as robust as I need:
-----
Moderator note: the link previously posted here has been removed at Graham's request due to concerns about a possible virus on that site
-----
However the thing is being offered at around 125 . . . can't be bad.

Grazie

Pete Wilie April 6th, 2005 11:29 PM

Carlos,

Sounds very interesting.

Would you mind posting the brand/model# of the parts you have bought so far, and who you bought them from.

Thanks,
Pete

Samuel Birkan April 7th, 2005 06:05 AM

I've been talking to some electricians and was pointed to this site that has some good info on dimming ballasts
http://www.lutron.com/ballast/ballast_prod.asp

Carlos E. Martinez April 7th, 2005 06:35 AM

<<<-- Originally posted by Samuel Birkan : I've been talking to some electricians and was pointed to this site that has some good info on dimming ballasts
http://www.lutron.com/ballast/ballast_prod.asp -->>>

Thanks, Samuel. Those Lutron ballasts, particularly the two-wire dimming types, certainly look interesting.

http://www.lutron.com/ballast/ballast_tuwire.asp


Carlos

Carlos E. Martinez April 7th, 2005 07:13 AM

<<<-- Originally posted by Carlos E. Martinez : Those Lutron ballasts, particularly the two-wire dimming types, certainly look interesting.

http://www.lutron.com/ballast/ballast_tuwire.asp
-->>>


Correction. Further reading tell me that the tuwire model might not be used with 55W lamps. They only seem to accept up to 50W lamps, which BTW I didn't know existed.

On the other side I am not too worried on dimming these lamps either, so maybe we should let go on that one and stay with simpler independent switches. We might be opening another can of worms if we don't.



Carlos

Samuel Birkan April 7th, 2005 07:18 AM

I was actually looking at the "Hi-Lume" with a T5-HO lamp.
One question I have is this, with a dimmer would the color temp not change as you dimmed ? Maybe it would be better to have each tube switched then you would have "steps" of brightness !

Carlos E. Martinez April 7th, 2005 07:28 AM

Re: FL-500 Imager
 
<<<-- Originally posted by Graham Bernard :

But looking real close it would not seem as robust as I need:

However the thing is being offered at around 125 . . . can't be bad.
-->>>

They look very good, Graham. They have several advantages:

- Good price
- They seem to be light weight
- Aluminum made, so should take a beating well.
- Have barndoors
- Have a support

Disadvantages:

- Lamps are up to 27W only. To use 55W lamps, perhaps box might have to be larger and heavier. Pity they didn't try it yet.
- Box support might demand using sand bags on the light stand base. Thought this might be a requirement on my project too.

An excellent suggestion, anyway. The lamp max wattage is the main limitation.


Carlos


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