GoE Labs: How-To,Lighting,Low Voltage Spotlights

Low voltage low cost PAR lighting (fc4 control fades etc...)
Shooting for ~ $10 +/- per piece

Safe, Flexible Low Voltage, with a Pro touch

• Index

• Parts List
• Fabricating the pieces
• Mounting Handle (Yolk) Fabrication
• Lamp holder Fab and Assembly
• Can Assembly
• Threaded Insert Installation
• Adding some ventilation
• Paint the 'Can'
• Put together the lamp assembly
• Assemble the Yolk and clamp
• Wiring it up
• Gell holder

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PARTS LIST

Low Voltage PAR lights
Item	Qty	$$$$$	Description
1	1 ea	$ 4.50	MR16 base and socket (all electronics)
2	1 ea	$ 0.00	Steel Coffee can
3	1 ea	$ 0.50	Terminal strip, or molex connector
4	asstd	$ 3.00	Gell material (red green blue etc...)
5	2	$ 1.20	Delta Knobs with screws Rogan Corp, Delta Clamping Knob
6	2	$ 0.14	1/4-20 threaded rivets
7	18 or 22 in	$~2.50	1/8 x 1 aluminum bar stock
8	1/10	$ 6.99	Cold Galvanizing Compound, Spray
9	1	$ 0.29	1/4-20 x 1in Screw
10	1	$ 0.29	1/4-20 x 1-1/2in Screw
11	1	$ 0.03	1/4 Flat Washer
12	1	$ 0.05	1/4-20 Hex Nut
13	2	$ 0.05	6-32 x 1/2 in screw
14	2	$ 0.02	6-32 Hex Nut
15	1	$ 0.68	1/4 x 1 inch, Nylon Spacer
16	1	$ 1.00	Small Plastic 'C' Clamp

Alu Flashing, 8" x 50' $14.99 for Gell Holders Should be able to get ~35 Large Holders or ~150 small ones from a roll. So assuming you're making 4 large and 6 Small cans you'd need ~88 inches (about 8 feet) Smaller 10 ft rolls run ~$9.69 (its easy to work with so you may want to opt for the big roll cost wise )

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Fabricating the pieces

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Can Preparation

Shake out any excess coffee grounds from inside the can.
Remove the outside plastic that labels the can, and clean off any excess glue that was used to attach it to the can.

Smooth out any rough edges on the opening end, so we don't get sliced up
At this point you may want to rough up the can surface with a bit of sandpaper/emery cloth, so we can get some paint to adhere to the surface,
Now clean the can, using a mild solution that won't leave a residue (like rubbing alcohol )

A little Rust proofing

After it is dry, we then give it a coat of 'cold galvanize spray' to improve its overall rust resiliency, this is by no means all the coating the can will get, but is a great base to start from.

Adding Holes

Now we have a can that is ready to start modifying for our purposes.
We need to drill some holes in the can for the mounting Yolk, as well as the bulb mount, We will be using a 11/32" bit for all of these holes (because we can, and its simpler to do so )


NOTE: the can is pretty thin, so be sure you have a sharp bit, and DO NOT use too much pressure, as you'll bend the can fairly easily !

For the bulb mount count up to the 2nd ribbed section of the can (from the closed end), and drill a hole in the center of that rib.

Next we drill 2 more holes for the mounting Yolk to attach to . These are positioned on the 3rd rib up from the bottom (just shy of midway up the can). These holes should be drilled approximately plus and minus 90 degrees from the existing hole (if you look at the can from an end) The 90 degree angle is not absolute, and the important part of the placement is that the 2 holes wind up on opposite sides of the can (as close as looks reasonable)

Mounting Handle (Yolk) Fabrication

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The exact size and bending depend on the size coffee can you are using,(17-19 in for a large can or 13-15 in for a small can Use a file to take the sharpness off the edges) We will need to Drill out 3 holes on the bar. The end holes should be approximately 1/2 inch from the ends, and the last hole dead center on the bar. Again drilled using the same bit we have been using all along.

Bending the Bar:

There are 2 options here you can make a simple U shaped yolk, or a more square [ shaped one.

U shaped
The simple U shaped one can be made by finding something that is the same diameter of the can, centering the middle hole on the surface, and wrapping the ends of the stock around it to create the U shape. Try to get the ends of the U to align as we will be sing the holes to attach to the can when we get there ...

Square Shaped
The alternate 'square' yolk you would measure from your center hole out the radius of your can (the radius being the measured diameter across the can divided in half). These measurements should also include a little extra ( a pencil width should be fine or ~1/16"). This marking is the INSIDE of the bend. I put mine in a bench clamp, aligned to the mark on the edge of the clamp, with the center hole also on the clamp side, so all I am bending is the area outside the marks going towards the mounting hole.

I then bend the stock 90 degrees along the edge of the clamp (and can use a hammer to make sure it is flat tight against the clamp and formed to my liking).

On either of the bars, rough up the surface in preparation for painting (sandpaper/emery cloth/sandblasting...etc), and clean the surface

Paint as desired, and Put this aside for the moment.

Lamp holder Fab and Assembly

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Make a piece that is rounded to the diameter of the can, and has a flat surface to mount the lamp assembly to.

Drill and Tap a () hole (or an 11/32 to install a threaded insert) on the rounded portion.

Can Assembly

NOTE: I think I may use "Jack-Nuts" next time around, as they are easier to install, and yo can forgo the inside washer (though I still recommend it). The installation is similar, but they are not as Beefy as the ones I had, so should be significantly easier to install

Threaded Insert Installation

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The 2 holes on the can that are opposite one and other now need to have threaded inserts installed into them.

Using a 1/4-20 hex bolt (as the tool) and a couple of 1/4-20 hex nuts will allow us to install the inserts without needing to resort to buying any expensive tools for the job.

The method I found that works pretty well is to
Take the 14-20 bolt, and run a hex hut all the way to the head. Take this and using the nut and the head of the bolt secure it in your bench clamp with the threaded end of the bolt sticking straight up. Be sure it is secure and tight, as we will be applying a lot of torque to things...

put another 1/4-20 nut on the exposed part of the bolt, then 2 1/4 flat washers. Screw your first insert onto the bolt, making sure the shoulder is facing down towards the head of the bolt, nuts and washers...

Position the can so that one of the opposing holes goes over the top end of the insert.
With the insert in place put a 5/8 Inch washer over the end of the end of the insert inside the can (this will add strength to the insert, so it resists being torn out or becoming loose)

Shown installing the threaded insert onto the Lamp holder (for clarity)

Now the 'fun part' we need to take our wrench and unscrew the loose nut under the can (up towards the insert). I say fun because while you are doing this you want to keep the can, and especially the washer inside the can, positioned relatively square to the side of the can.
With all this sandwiched together we keep unscrewing the nut. As the nut rises to the can, it will get extremely tight ... just keep going.

What we are doing at this point is pulling the back of the threaded insert (the part that is threaded towards the outside edge of the can. This causes the insert to bulge at its base and rivet itself in place.

We need to tighten this to at least the point where the washer inside the can is seated against the can and is firmly there (no wiggle or spin allowed)

Once cinched down enough, you loosen the nut by backing it off (rotating clockwise) away from the can.
Take the can and firmly, but gently unscrew it from the bolt (on the bench vise)

Repeat this for the other side of the can.

Adding some ventilation

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Finally we get to the easy part. We do this using an old fashion can opener, and evenly putting holes in the bottom. Only ' open ' the hole about 1/2 way.
I find it easiest to start one, then go on the opposite side of the can for the next. then again half way in between the 2 and again to the opposite side. Continue bisecting the can thios way till you have at least 8 openings.

Add another hole in the side of the can Opposite your Single mounting hole. You may want to use a rubber gromet, as this is where the wires will exit the can. I used a piece of insulation I had lying around from another project. A little silicone and its secure

Paint the 'Can'

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Now its a good time to do some more painting on the can, its not a picassa, so we really don't need to be too finickey.

First paint the inside of the can, with either a 'chrome; or glossy white. Cost it well, especially the opener holes in the closed end, and coat it well up the sides too.

Once the white is dry enough, flip the can over, and paint the outside, and back end (on top) a flat black, or glossy, or if you want camo .... whatever suits your needs.

Be sure its dry before assembly of the parts into it in the subsequent steps

Now Put together the lamp assembly

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Drill a couple smaller holes (1/8 or so) on the flat part of the bracket. Using the Lamp holder Mark out where to drill. This is where we will attach the lamp to the bracket, using teh #6 1/2 inch screws, and nuts. A dab of locktite (thread lock) will insure they stay put.

Now we install the Lamp Assembly into the Can and secure it with a 1 inch 1/4/20, because we used the insert

Assemble the Yolk and clamp

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Drill an 11/32 in hold in the clamp as shown.
put a 1-1/2 inch 1/4-20 screw thru this hold from the inside. Add the Spacer then the Yolk, attaching it with a Flat washer and Nut.

Wiring it up

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Add a connector to the exposed wires. You will want to have sufficient slack to be able to remove the lamp assembly, as it will be easier to replace the lamp if you can. Since I already use 4 Pin molex connectors, and the lamp came with one that is what I'll use. This gives me the ability to use LV extensions to get things where I want.

Gell holder

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The holders are made with the Aluminum Falshing, because its light, fairly easy to work with. Because the gells themselves are really light so we don't need anything very heavy.

Cutout the basic size(s) for your Can.
for small cans cut out a 6" x 10" piece.
for large cans cut out a 16" x 8" piece.

Now we fold the piece in half so we wind up with a Square piece, keeping the folded edge intact.

Now draw an X across the entire square. Then measure your edges, and find their centers (on all 4 sides) so we can now draw a + on the square ( we should now have an asterisk with most of the lines crossing in the middle of the square.

Place your cans lid (can be on the can) in the center of the square, and use it to draw a circle. This should be the can you are using for the light, as we will be fitting this square to the light

Now find something to draw another circle. This should be sized so that there is about 1" between this and your original circle.

Anywhere near the center of the circle we will need a hole to get our tin snips into. Cut out only the small inside circle !

from the inside circle now cut on the asterisk lines out to th
e outer circle and STOP at the circle. Once that is done, cut the tabs we have created, in half again (so we will have 16 sections that stop at the outer circle).

Gently open the folded piece carefully seperating the front and back layers from one and other. you only need to open it about half way (about 90 degrees), this one actually seperated at the fold, and became 2 pieces, as shown in the pictures from here on, so I will note any variations going forward.

On the marked side now we cut out the outer circle. ONLY on the marked side. Leave the tabs on the other side. This side (with No tabs is the front of the holder)

Drill some 1/8 inch holes 1/2 inch in from the outer circle, near the center of at least 2 of tabs. These tabs should be opposite one and other (eg top and bottom / left and right tabs)

FOR ATTACHED PIECES:
Now we fold the piece back together flat. Place your can (or better yet a raw can) on your work surface, closed end up (just because it makes sense strength wise)

Take your aluminum square and place it over the can, with the full hole side down over the can (it should fit over the edge without binding.

Now put on your work gloves and firmly work the aluminum onto the can. The tabs should be bending up towards you. What we want is the tabs to stick straight up, and fit snugly around the can. If done correctly, this piece should now friction slide onto the can. Slide it over the can and form the tabs to the sides of the can as needed them remove the can from the square.
NOTE:If you are making several of these you can make a tool out of plywood to help this setp along. This could be laid out similar to the aluminum with the larger circle cut in it. This way you could place this over your aluminum square (that is started on the can, as described) and use it to press fit / bend the tabs in place quickly and accurately

FOR SEPARATED PIECES:
Place the piece with the cut tabs (asterisk) and bend each tab up 90 degrees. Make sure they bend as close to the ends of the cuts as possible, to give you a nice wide hole in the center.

BOTH:
With the square in front of you (tabs up) measure off 1 " from each corner and draw a line between. Cut the corner triangles (2) off on the folded edge (top piece with the flaired up fins if seperate), and NOT on the open edge.

Clean up (file) any sharp edges on the piece anywhere.
OPTION:RECOMMENDED FOR SEPARATE PIECES
If you want you can fold 1/4 to 1/2 inch on the edges adjacent to the folded edge up slightly less than 90 degrees. This will give some rigidity to the holder, and also help hold the gell in place

lightly sand the surfaces, and paint flat black.

Once dry this can now have a piece of gell material inserted, and it can be fit onto the can.
If the holder is loose, you can drill some holes into the can (where the tabs have holes) and use sheet metal screws to hold it on.