This is an easy to make, relatively low cost table or wall mounted lamp. Intermediate skill level is suggested. Two sizes are offered, small ( 10" x 6" x 6" H) or large ( 12.25" x 6.5 x 7.25 H.The shell can be made from paper or translucent plastic, and the base is wood. There is an option to make a colored filter from a theatrical gel.
Step 1: Materials and Tools Needed
You will need sheets of paper or plastic that are translucent which allow light to pass through.
You will need 18" x 24" for the smaller lamp and an extra 12" x 18" for the larger.
For small to medium sized lamps .30 - .035" thickness is ideal for plastic.
Research from other Instructables in lighting found this to be readily available and low cost.
- HDPE: High Density Polyethylene works well, looks good, and is easy to get.
Tap Plasticssells a large 24 x 48" sheet for $ 7.75. It is good quality with a texture, better look and feel than the less expensive, industrial grade, online offering below.
Online: http://www.usplastics.com sell a lesser quality and cheaper HDPE sheet, but you'll pay shipping from Ohio.
You will need a lamp fixture - see photo. Just a raw socket on a cord with a plug, that includes an in line on/off switch. I found one at Home Depot for $8 with a small candelabra base, and some LED bulbs. I'd recommend using a LED candelabra base bulb.The incandescent option is a lot less expensive but creates heat and has a much shorter lifespan. The LED costs more but lasts a lot longer and does not build up heat in the 40 and 25 watt output versions. The 40 W version works well for the large model and the 25 W bulb is fine for the smaller one.
Wood base- Any 3/4" wood will do , solid softwood or plywood. 12" x 8"
Optional- White paint or tape to cover the edge of the plywood.
Electric socket with a cord and plug attached and ideally with an inline switch along the cord.
Here is the Home Depot offering ( $ 6-) : in white or black. This set requires no modification or dismantling.
Feet and fastening device: Plastic feet can be purchase from Ace Hardware or made from 3/4" dowels.
Cover Shell Fasteners: I'd recommend using a threaded brass insert and a compatible nylon machine screw with washer 1.5" long . ( see photo) Ace Hardware carries these . A 10 -24 thread is what I used.
You can get away with using any # 6 or # 8 wood screw with a plastic cap to cover the screw head, but it may be more difficult to assemble.
Recommended tools; Laser Cutter, Drill press, Band saw, and disk sander, Hand tools; file, screw driver, tape measure, tri-square
Step 2: Cut Out the Shell Parts
Use either the small ( 10" x 6" x 6" H) or large ( 12.25" x 6.5 x 7.25 H) patterns for the shell slices.See related PDF and DXF files.
There are five pairs of shapes ( a left and right set) and one center piece. Eleven total pieces.
I used a 60 W Universal Laser cutter.The setting was Polypropylene material at .030" thk.
I turned down the Vector cut - 28 % to try and avoid burning.
I'd recommend a test cut to see how the material is behaving, adjust to reduce burning. Once you have the setting dialed in, cut the material. Make sure it is as flat as possible on the laser bed and tape the edge in a few places if it wants to not sit flat.
** Be sure to note which side will be the face and place that side face down.There is often ,but not always, a front and back to the material. The TAP plastic I used had a definite textured matte front and shiny back.
Before removing the parts after cutting use light tac tape and number the pieces.1-5 on one side and 1a, 2a etc. on the other for similar shaped parts- # 6 the center and longest slice is obvious and needs no label.
After cutting you may need to cleanup some small burn marks I found soapy water or windex to work fine.
The parts may require filing or light sanding the edges. I filed the rolled edge off, some sanding will likely be needed.
Step 3: Layout and Cut Base
Use the pattern for either the large or small base and trace it onto the wood.
or if you have a Shop Bot or similar N/C router you can cut everything using the PDF file.
A 1/4" end mill will work fine.
Scribe the x - y axis on the part especially where the 2 axis pins will be drilled.
Be sure to draw center lines in the x & y axis. Cut out the form on a band saw, then sand the shape
on a disc sander leaving it 1/8" longer at both tips. This is to ensure a snug fit of the shell.
After sanding extend the lines across the thickness at the pivot point to locate where your inserts will go.
You can do a quick fit check by wrapping the #1 shell slice around the perimeter while lining up the holes of the slice at the center line on each side. Make sure the shell slice is pressed up against the side of the plywood perimeter,If there is gap at the top between the part and the plywood the plywood is too small. This should not be the case though.
The plywood should be 1/8" too large at each end, that is what we want for now. So when you wrap the slice around the oval, the hole stops short of the center line. We will sand the two 1/8" peaks down later after the inserts are in place, or you can do it now if you are careful and accurate. You'll need to sand to fit both ends using the 2 identical slices.
Drill and Fasten Inserts
Drill the holes for the brass threaded inserts. Test drill on a flat scrap to be sure to get the correct diameter. It's usually 2- 3 steps smaller than the outside diameter of the insert. Once you have done a practice drill and insert. Set up the drill press as shown. This could be done with a hand drill, but the accuracy of a drill press is hard to match. Use a center punch for accuracy before drilling. Drill about 1/2 " deeper than the insert. Screw in the inserts carefully. This point you can screw in both slices #1 with the nylon screw and carefully sand the extra bit of the peaks of the curve, checking the fit often, so the slices conform easily to the respective curves but are not loose. Make sure the slices stay well clear of the sander.
When the fit is just snug, you can remove the screw and slices.
Cut Center Hole for cord set:
Now cut out the hole for the cord set and receptacle. Use the attached pattern.
and then either paint or tape the edge if you like. It will look cleaner when fully assembled.
Trim or clean up any excess.
FEET: Layout and drill pilot holes for the feet- If making the feet use 1/2- 3/4" diam. dowel approx 3/4" H. Drill an1/8" thru hole in the center and a counter bore 1/4" deep for a # 6 # 8 round head screw. Add adhesive felt pads to the bottom after fastening, if desired.
Step 4: Assemble the Shell
Layout the shell slices in order at opposite ends. Using a temporary pin a finish nail or screw stack the slices as shown, alternating left and right staring with 1 then 1a, 2 then 2a until you reach the last #6 in the center. Close the fan , grab tightly and remove the temporary pin while inserting the nylon screw into #6 slice first, with #1's at the back. Take the whole bundle and screw in loosely to one side. You can wrap around and screw in the other side or separate the slices now L,R,L,R etc. After fastening both sides, insert the bulb and test.
COLOR OPTION: See the next step for cutting and making a colored lens for the bulb, you can clear tape it down now if you decide to make this.
Then separate the alternate slices to their respective sides. Allow about 1/8- 3/16" overlap. It's kind of tricky to keep even, as a helper use masking tape to hold the slices in place as you work your way up both sides to the center. Once you are happy with the overlaps you can then tighten down the screws then remove the masking tape.
Plug in the lamp and enjoy.
Step 5: COLORED FILTER OPTION
To add an color accent you can make a colored gel to go around the bulb. Alternately you can use LED strip or adhesive tape lights with a transformer and a dimmer/color changing controller. The whole set up will run around $ 80 -$ 100, but will allow all kinds of options for color sequencing and dimming.
To make this filter , you can buy color theatrical lighting gels Lee or Rosco ,
online for about $ 7.00 a sheet ( 20 x 24")
One source is here;
Another local San Francisco walk up source is:
http://www.holzmueller.com/ They sell them for $ 8.00 and you can see the many colors available in person.
Gels will lessen the light transmission and you can see on the spec of the gel how much light will pass thru. The higher the number ( 80- 95% )the lighter the tint and brighter the light , the lower the number ( 30- 50%) the darker the color and less light passes thru.
Use the attached pattern to cut your gel on a laser or print it an cut by hand by laying it under the gel and using an exacto knife. You can magic tape this together and tape down to the base , over the bulb before setting the shell slices.