# DIY Cantilevered Light Fixture



## hoppycalif (Apr 7, 2005)

Niko jolted me into thinking "outside of the box" on light fixtures with this great thread: http://www.aquaticplantcentral.com/...ltra-efficient-inexpensive-monster-light.html
So, I designed a cantilevered light fixture that is a "pendant" style, but on a parallelogram linkage. This will allow me to swing it up out of the way, but still have the light directed down into the tank, and changing bulbs will be relatively easy. I will use this with an open top tank, in place of my current fixture that sits on the tank with the front half hinged to lift up.

Today I started making the actual fixture body, from 1/4" MDF, a simple box, but with the front and back angled so I can use mylar on them to help direct the light that would over shoot the tank top back into the tank. I will use my current 2 X 55 watt AH Supply kit, and the down position of the fixture will put those bulbs about 4 inches above the water vs. the 2" height they now sit at.

Here are my design sketches, which should be understandable without notes, I think:


















The parallel links will be made of 1/2" x 1/8" aluminum bar. There will be an electrical outlet in the wall mounted box that the links attach to, for the lights, with the power coming by way of a timer mounted below the tank.


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## hoppycalif (Apr 7, 2005)

The body of the fixture is coming along well:










First cut out the two end trapezoidal pieces, making them identical by stacking two pieces and cutting them at the same time. Then cut the front and back long pieces, making sure they are the same length. I set my skilsaw to cut at an angle, using one of the end pieces as an angle gage. That left the top and bottom edge at the right angle. These four pieces are then glued together - simple butt joints. (Which is when I discovered the front and back pieces were about 3/16" wider than they should be, so I have to trim them later.) Finally, cut the top piece using the same angle setting on the skill saw for the front and back edges to match the end piece angles. This is then glued on top of the assembled four pieces, using it to square up the "box". (I let the glue dry from the first glueing before glueing the top on.) After a short drying time, I used cut off strips of the MDF to reinforce all of the inside corners, which is when the photo was taken.


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## CraigThor (Aug 5, 2007)

Hope this works would love to do something like this over my 75... how will it stay in the up position?


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## hoppycalif (Apr 7, 2005)

The fixture "box" is finished, other than painting. I used a router to trim the front and back pieces, and to cut ventilation slots on top, the used a random orbit sander to clean up the joints. The first picture shows it sitting on top of my existing hood, and the second is the "box" showing the ventilation slots.


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## hoppycalif (Apr 7, 2005)

CraigThor said:


> Hope this works would love to do something like this over my 75... how will it stay in the up position?


I'm sure it will work, since I'm always sure my ideas will work, even when they don't. It will stay up by putting a spacer block between the links on one side - the exact design of that I haven't figured out yet. Since the links will not be able to close, the fixture stays up.

I ordered the mylar for the front and back pieces, to make them reflective, to capture the light spillover and direct it to the tank, from treefish who, fortunately, had one piece left to sell. Tomorrow I will go look for the aluminum bars, and the electric outlet and junction box for the outlet - both being the smallest I can find.

Now, a question: you can see that I have a light fixture now that is the same oak material as the cabinet and the fake oak trim on the tank. This won't easily finish with an oak finish, so what is the best paint color to use? I'm vacillating between the off white of the wall and black or gray. The aluminum link bars can be left plain or finished the same color as the fixture.


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## newbie314 (Mar 2, 2007)

Do you go to blue color for the aluminium.
That place is great.


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## hoppycalif (Apr 7, 2005)

newbie314 said:


> Do you go to blue color for the aluminium.
> That place is great.


What is "blue color"? No, I just visit Emigh's Hardware on Watt, where they have a nice selection of aluminum, both sheet and extrusions. I considered making the "box" out of aluminum sheet, just for the experience, and as an excuse to buy a pop rivet tool, but that seemed wasteful, to say the least. I knew I could make a nice one with MDF, so that's how I went, at a cost of $4 for the material.


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## CraigThor (Aug 5, 2007)

Hoppy, to hold it up what about a slide bar latch like used on older inside doors/ restrooms?

Craig


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## niko (Jan 28, 2004)

Hoppy,

I don't understand - when pushed "out of the way" the "hood" will end up behind the tank or what?

--Nikolay


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## hoppycalif (Apr 7, 2005)

A latch like this?









That would prevent the links from collapsing in contact when the light is down in position, which is what positions it there. Or did I miss something? A "U" shaped one would do it, if I didn't lose it.


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## CraigThor (Aug 5, 2007)

hoppy something like in this link maybe smaller.

http://www.hooverfence.com/woodfence/slideblatch.htm

Craig


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## hoppycalif (Apr 7, 2005)

niko said:


> Hoppy,
> 
> I don't understand - when pushed "out of the way" the "hood" will end up behind the tank or what?
> 
> --Nikolay


It ends up against the wall, about 10 inches above the top of the tank, giving great access to the tank for maintenance.

I ended up with this design after trying to use drawer slides to make it easy to shove the fixture back from above the tank. But, I only have 4 inches clearance between the tank and the wall, so I couldn't make it go far enough back. Then I decided to also hinge it so it would slide back and then tilt up. But, that left the light shining in my face. Then I remembered the parallelogram linkage, and spent a couple of days playing with that before I understood how to optimize it. Now I think I have what I wanted - good access, nothing above the light to see, easy to change bulbs, an open tank top, and no cooling fan needed. It is a pretty cheap thing to try out, since I will use my existing AH Supply light kit.


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## hoppycalif (Apr 7, 2005)

CraigThor said:


> hoppy something like in this link maybe smaller.
> 
> http://www.hooverfence.com/woodfence/slideblatch.htm
> 
> Craig


Great idea! A small, simple version of that can sit on top of the wall mounting and either slide into a hole in the back link, or just block the movement of the back link. As I recall, Ace Hardware has some little brass ones that might work.


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## CraigThor (Aug 5, 2007)

yup, I had to google it to find that picture but it should work great.


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## newbie314 (Mar 2, 2007)

hoppycalif said:


> What is "blue color"? No, I just visit Emigh's Hardware on Watt, where they have a nice selection of aluminum, both sheet and extrusions. I considered making the "box" out of aluminum sheet, just for the experience, and as an excuse to buy a pop rivet tool, but that seemed wasteful, to say the least. I knew I could make a nice one with MDF, so that's how I went, at a cost of $4 for the material.


Sorry should have been blue collar. Has lots of misc. stuff. Like already cut plexi-glass. You don't have to buy a whole sheet. Take a long strip.
I got aircraft aluminum piece for making my brake bracket on my electric scooter.


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## hoppycalif (Apr 7, 2005)

I found that Blue Collar place in the phone book, but I already visited Emigh Hardware. They had little or no aluminum, but lots of iron bars. I quickly found out that aluminum bars wouldn't be strong enough, since the iron was just about the right strength. So I bought a 4 foot piece of 1/8" by 1/2" weldable steel bar. That will make the 4 parallelogram links.

My wife objected to my MDF fixture box, so she "persuaded" me to cover it with oak veneer. That will likely be the job for tomorrow. I'm up to $29 for materials now, but very little else to buy.


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## hoppycalif (Apr 7, 2005)

I made the links and the wall mount board, and assembled it for the first time today:









The first lesson I learned is that it will take two barrel bolts to lock this in the "UP" position. With only one it twists very badly, which is obvious when I look at it. But, the concept seems to work just fine. I can't photograph it in the up position now because I don't have enough hands to hold it up and take the photo too. Tomorrow I will mount this on a piece of scrap plywood to simulate the wall, then install the barrel bolts. My costs are now up by another $9, plus $15 for contact cement for the veneer and a can of Rustoleum paint for the links.


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## CraigThor (Aug 5, 2007)

hoppycalif said:


> I made the links and the wall mount board, and assembled it for the first time today:
> 
> 
> 
> ...


Looking good, would like something like this for my 75. what size tank is this going on? Mine is 4'

Craig


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## Tex Gal (Nov 1, 2007)

Hoppy it looks good.  If there were something you could use other than that heavy MDF. I was gonna suggest the faux wood grain finish to match your tank trim. You would use a graining tool and 2 tone stain/paint. Sounds like you have it solved with veneer.


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## hoppycalif (Apr 7, 2005)

CraigThor said:


> Looking good, would like something like this for my 75. what size tank is this going on? Mine is 4'
> 
> Craig


My tank is a 45 gallon tank, only 30" wide (actually closer to 29"). The wider the tank the harder it will be for the linkage not to twist. If I were going to try it on a 48" wide tank I think I would put more room between the two links on each side, which requires the tank be further from the wall, if you want to raise it a significant amount. And, I would use 1" x 1/8" steel bar for the links, for more stiffness. Then I think you could raise the fixture with one hand, push the barrel bolt in place to lock one side, then switch hands and push it in on the other side to lock it. Since raising it would be for major maintenance only, it can be a bit awkward and not be a problem. Or, two people could easily raise it and lock it up.

Before I am willing to say I like this, I want to get it finished and installed. So, the "jury is still out".


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## hoppycalif (Apr 7, 2005)

Tex Gal said:


> Hoppy it looks good.  If there were something you could use other than that heavy MDF. I was gonna suggest the faux wood grain finish to match your tank trim. You would use a graining tool and 2 tone stain/paint. Sounds like you have it solved with veneer.


One quarter inch MDF is actually pretty light weight, but it is ugly. The best material would be sheet aluminum, and I will probably always wish I had tried that. (Then my wife would have been much less insistent on the oak veneer!)


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## hoppycalif (Apr 7, 2005)

The basic system is all assembled now. And, it works!


















I left all of the screws that act as pivots fairly loose, so it wobbles a bit and the clearances let it sag a bit when it is down, but when I tighten everything, I think it will be fine. I do need to load it with something heavier than the light fixture just to be sure it is sturdy enough in the down position. Onward!!


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## treefish (Oct 10, 2007)

Ingenious design!

No doubt the finished product will be awesome.


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## hoppycalif (Apr 7, 2005)

This would work commercially, with adjustable length links, and friction locks on the back pivots. Then it would do everything except prune the plants!


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## DMHdispute (Oct 23, 2007)

I was thinking of a hood design similar to that and thought of using little hood struts that they use for cars to hold it up. The only probelem that i can think of is that the struts could be too strong and make it go up too fast but then youd just have to hold on to it real good.

It looks real good.


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## niko (Jan 28, 2004)

Ok Hoppy,

Nice! Just why MDF? It seems heavy to me, but I really like the mecanism to move the fixture.

I see that after this cantilevered contraption you will be up for another challenge when you see my new creation 

It seems that I will be building a T5HO light containing five 60" long Giesmann Midday bulbs (80 Watt each). The light has to cover the tank because the light spill from a hanging fixture will be too much in the living room. The tank is 6' long X 21" deep X 18" wide. My current plans are:

- Super slim profile
- All metal housing
- Perforated metal top plate (ventilation, reduce light spill, looks)
- 2 hinges on the back of the tank
- Small locking mechanism located on the back rim of the tank to keep the light un raised position
- Individual reflector for each bulb
- Remote ballasts (very light fixture above the tank)
- No visible wires
- 5 levels of illumination (80, 160, 240, 320, or 400 watt) 
- Moonlights
- The light from each bulb can be directed by rotating each reflector around the lamp
- Very low heat (can put and hold your hand on the fixture)
- Price: about $400 for all materials

--Nikolay


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## hoppycalif (Apr 7, 2005)

Niko, I am basically a woodworker, so I see solutions to problems as woodworking jobs. But, in this case I planned all along to make this from aluminum sheet, but as I got more excited about the linkage idea I got less excited about struggling with sheet metal and acquiring the hand tools needed to use it. Then I remembered that I could get 2' x 4' panels of 1/4" "hardboard", which is MDF at Home Depot, for $2 each. Being a cheapskate that appealed to me, so I used MDF. I admit that I kind of regret not going ahead with the sheet aluminum.

If that big tank you are making a fixture for sits near a wall the parallelogram linkage would work very well for it. Then maintenance in the tank would get much more pleasant, with the light up and still lighting the tank.

Be sure to take lots of photos and show them here as you go along. Maybe it will inspire me again and I can drive my wife nuts by starting an even better fixture then!

DMH, telescoping struts, similar to what is used for a microphone stand, for example, could be adopted for a linkage too. Once you adopt the linkage idea there are several ways to do this that offer lots of flexibility on height of the light above the tank, distance from the wall, height of the raised fixture, etc., but those ideas are all more complicated too.

I'm still fascinated by the idea of using drawer slides to provide the ability to move a light fixture back, but I can't yet see a good way to raise it and use drawer slides, too.


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## niko (Jan 28, 2004)

Hoppy,

The fixture is for TexGal and she just told me today that she has 4 inches between the back glass of the tank and the wall. I don't want to make her drill her wall but I can certainly mount the cantilevered beams to 2 vertical posts affixed to the tank stand. Basically what you show here but not attached to the wall. 

I really like the idea to combine what you show here with what I will make. This is geting really exciting!

--Nikolay


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## hoppycalif (Apr 7, 2005)

niko said:


> Hoppy,
> 
> The fixture is for TexGal and she just told me today that she has 4 inches between the back glass of the tank and the wall. I don't want to make her drill her wall but I can certainly mount the cantilevered beams to 2 vertical posts affixed to the tank stand. Basically what you show here but not attached to the wall.
> 
> ...


Put a pair of kitchen drawer slides on it and I will be happy as a clam!:heh:


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## hoppycalif (Apr 7, 2005)

I finished veneering the fixture and gluing in some aluminized mylar to make "wing" reflectors and redirect some of the light spillover into the tank. Hopefully I can get this all installed tomorrow!















I found that veneering can be much harder than it looks when you work with bigger pieces. I messed up the top piece of veneer, but managed to make it look reasonably good, considering that it will not be a focal point of the aquarium. Contact cement really is a bear when you accidentally let the two surfaces contact before you are quite ready.


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## hoppycalif (Apr 7, 2005)

It is installed, and but for the difficulty in installing it with the full open topped tank in the way, and my fuzzy brained mistakes, it works great! Here it is:









With the hood in the up position, look at all of the working room I now have.









Here is the fixture with the AH Supply lights installed;









I think, for those with the goals I had, and with a tank located near, but not too near a wall, this is a good solution.


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## hoppycalif (Apr 7, 2005)

A few more comments: There is no light spillover at all in either the front or the back, but there is still a little to the ends of the tank. The "wing" reflectors I added seem to do just what they were intended to do - capture the spillover and direct it into the tank.

Here is what the lights look like from the bottom: (9325K bulbs, so the color balance is totally off)









One of those two bulbs has never been used before and the other has just over a month usage. I don't know which is the "dim" one. They look the same to the eye, but not to the camera.


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## wantabe23 (Apr 6, 2005)

nice work hoppy! I am really grateful to all the work and experimentation you do and then post on this site. I just read through the drop checker DIY, and now this, it is great information as to how to make an aquarium great that would other wise be normal. Thanks


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## cs_gardener (Apr 28, 2006)

That is really a great idea and it looks nice too. You can see what you're doing while performing tank maintenance and no chance of knocking the light into the water. 

BTW, you've got a great looking tank. The background plant is great, I love the way it curves and flows - it looks like a forest going on forever. It's also kinda like abstract art. I find it fascinating.


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## manifresh006 (Jul 20, 2007)

Looks like u just bought it from store...lol
Nice DIY


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## wiste (Feb 10, 2006)

Great project. Any thoughts on how this could be done if the wall mount is not practical?


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## Tex Gal (Nov 1, 2007)

WOW! Your wood matches perfectly! Great color matching!! It really looks nice. You are quite the handy man! Your wife must be proud! 

I'm very excited about new lights! The idea of not having to lift off, stack, have even light, moonlights, etc is very very exciting! You guys are just amazing!!! :yo: Hats off to you!


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## kakkoii (Jan 18, 2008)

your tank looks great by the way!


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## treefish (Oct 10, 2007)

Very nice,

I may have borrow this design. This is definitely going in my "future projects ideas list."

Great use for the mylar too.


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## hoppycalif (Apr 7, 2005)

treefish said:


> Very nice,
> 
> I may have borrow this design. This is definitely going in my "future projects ideas list."
> 
> Great use for the mylar too.


But, just wait for the solar cooker!


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## hoppycalif (Apr 7, 2005)

wiste said:


> Great project. Any thoughts on how this could be done if the wall mount is not practical?


If you were unable to mount this on a wall, you could mount it on brackets mounted on the back of the tank stand/cabinet. To crudely illustrate: nail a vertical 2 x 4 to each corner of the stand. On the back of the 2 x 4's mount a horizontal 2 x 4. Mount this light fixture to that horizontal 2 x 4.

I've been wondering if there were a way to manufacture the parallelogram linkage so it was of adjustable length, and have it mount on the back of any light fixture and to the wall. I'm convinced it is a pretty simple engineering job to design such a universal mount, but since I don't work with metal except for rare occasions, I can't make a prototype. But, I would think there would be a market, given the increasing popularity of open topped tanks.


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## JERP (Feb 4, 2003)

I used a similar concept for a "sit-on-top" light fixture. It's purely functional and ugly as hell, but normally covered by the canopy hood. I can open the hood and move one light fixture out of the way with this setup for maintenance. Shown is the "up" position without the hood on. The light fixtures rest on it's own arms in the up position like your's does in the down position. The only reason I brought it up is that no latches are required. This works out well for fixtures that sit on the tank, rather than attached to a wall. It worked out well for me. I wanted to be able to clean the tank with some light on it. I worked out a more elegant solution, but never built it. I tore down the tank several years ago and am now using a different set up.

http://home.pacbell.net/jrplanck/hoodup.jpg


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## hoppycalif (Apr 7, 2005)

This fixture has worked extremely well for 4 months now. I enjoy it so much I wouldn't change a thing, other than the little mistakes I made in making it.

Now, I am fed up with high light intensity. Bah! I took a week vacation, followed by another week recovering from a head cold, followed by almost another week being too busy with one of my wife's projects to work on the tank, and....... Well, I have a mess. Good time to make major changes.

With this fixture I could replace the 55 watt bulbs with lower wattage, but then I would lose the 9325K bulbs, which I really love. So, I will raise the fixture by about 9 inches, which will be the equivalent of reducing the light intensity by about 38%, from about 2.4 watts per gallon to the equivalent of about 1.5 watts per gallon (based on the intensity at the substrate level). This will entail only removing the bracket from the wall and relocating it 9 inches above the top of the tank. Easy to do. One more thing I like about the design.

I will probably be posting a new thread about the new setup, once I figure it all out.


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## missewell (Jul 12, 2007)

Amazing DIY. Talk about practical. Nice tank


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## sonaps (Nov 15, 2005)

I saw this for the first time today. Great work Hoppy! I like that when you raise it to work in the tank the lights are still pointing down. I look forward to seeing the new setup. I'm interested to see how this fixture looks when it's mounted higher.


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## hoppycalif (Apr 7, 2005)

Here is how it looks, raised 6 inches: Don't look at the tank - I'm in the process of converting that mess into a low light anubias, crypt, Java Fern tank.










I liked the appearance better when it was down just above the tank, but it isn't too bad this way either.

HEY! I SAID DON'T LOOK AT THE TANK! DANG IT!


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## hoppycalif (Apr 7, 2005)

I finished designing a universal mount for light fixtures, using this basic parallelogram linkage design. Since I don't need one right now I didn't make one, but the design is so simple I don't doubt it will work very well. It is on a PDF file which you can download from: http://www.oregonaquadesign.com/hoppyscantileveredlight.htm. 
EDIT: Change website reference above.


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## RestlessCrow (Nov 5, 2009)

DMHdispute said:


> I was thinking of a hood design similar to that and thought of using little hood struts that they use for cars to hold it up. The only probelem that i can think of is that the struts could be too strong and make it go up too fast but then youd just have to hold on to it real good.
> 
> It looks real good.


FYI Those hood struts are available in many different strenghths... (EXPENSIVE though!) I once helped someone convert an enclosed trailer to a "Concession" type trailer with a swing up door cut in the side... We went through about three sets of these buggers until we got the right ones.

I'm watching this one closely, because I'm building a similar setup for my 85 gal. I just completed my hood the day before yesterday and went over to my buddy's welding shop for a consultation.. (He loves all these crazy projects I get myself into)

Probably Tuesday I will get on to building my lift mechanism, but I'm building mine right on the top of the tank. No wall mount.

Looks good though! Great Job!


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