I decided to write this Instructable for three reasons. 1) there are, as far as I know, no other instructions as to how one would go about making a light fixture like this, 2) I have access to a laser cutter at my school, which makes the process much easier, and 3) I have a set of Laurel lamp bases that are missing their glass mushroom shades and I need replacements.
I’m sorry that I cannot give what I consider a full intractable – what I am presenting here is how one would go about creating a string lamp for their individual needs based on a few consideration.
From what I have found there is only one book that talks about anything close this subject. It is a small booklet titled “Stringcraft in 3D” and is Leisure Crafts 54 (from a series that as far as I can tell has 55 titles on various crafts) and is published Search Press London (so they call Plexiglas Perspex). If you know of any other books please let me know.
Step 1: Lighting Hardware
Is your lamp a lampshade, a hanging lamp, or even a sculpture. The hardware should be purchased first so that the string lamp can be build for it – remember the string lamp will be your custom design, the hardware will not. Lighting kits for all types of lamps can be purchased from home improvement stores or online but one of my favorite is from Ikea, the HEMMA. This series includes a cord that can be hung as well as table lamps that a string shade could be built for. While at Ikea resist the urge to just buy one of their lamps for you home…
My hardware is my Laurel lamp bases.
Step 2: Materials
This is the acrylic, Plexiglas, or other material (wood is cool). This must be chosen next because all the parts of the lamp will slotted together, and even though a certain material says its thickness is 3/16” it doesn’t mean when you get it home it will actually be 3/16”. It is usually thinner and therefore the pieces will be too loose to be assembled without gluing. The material must actually be measured before the actual design is laid out.
When choosing the material one needs to first consider what look one are going for – true 70’s disco, glam or an updated throwback look. Whatever you choose, I would advise staying away from mirrored acrylic because while the front will be mirrored the back (which will show because there is now no back on this type of lamp) will be a dull gray or black.
I chose white acrylic.
Also what type of string will the lamp be strung with must be considered. This needs to be known so the depth of the notches can be correct and not be too deep or too shallow.I chose white crochet cotton.
Step 3: Software
This is how you will design the lamp and how it will be cut. I designed mine with Rhinoceros, converted it to Adobe Illustrator, and then sent it to the laser cutter as school per their specifications.
I’m sorry I can’t give you much more information here, but each person has access to different software and each laser cutter reads different file types – One should determine the laser cutter specs and then move forward. The laser cutting technician should be able to advise you on this and the next step.
You may be hand cutting – if you are doing this refer to “lighting Hardware” and this time to do not resist the urge to buy an Ikea light fixture and forget the whole thing.
Step 4: Planning and Design
This is where you take the hardware and the material and decide how it all comes together.
For my lamps, the shade will site on a base. The base has a ring 3 3/8” wide and then a flange of 4 1/8”.
So I wanted the shade to have a hole that the ring will fit through and then it sits on the flange – but the ribs that support the string must not interfere with the flange.
I made two discs that will support the ribs: both are 5 1/8” in diameter with ¼” notches for each rib – this means that when the ribs (which also have ¼” notches) are slotted in the take up ½” each – one disc is solid and one has a hole that is 3 3/8” in diameter to fit the ring.
For a hanging light you would have an open bottom disc (for inserting the light bulb) and a hole at the top for the hardware to pass through.
Step 5: Size Calculation
So for a lamp one has the desired height (this will not change during calculation) and the width.
For my shade I held up an 18” ruler to my lamp base and decided on a shade that was around 17” wide by 7” high – about the proportions of a mushroom shade that I was trying to recreate.
So I started with my disc of 5 1/8” which equals 4 5/8” due to the ¼” slots on each side (5 1/8” – ¼” – ¼” = 4 5/8”).Each rib will be 6” which equals 5 ¾” when the ¼ slots are removed. 5 ¾” X 2 + 5 1/8” = 16 5/8”
Step 6: Notches for the String
My notches were made 1/8” deep which was far too deep and I would make them 1/16” deep. The deep notch was made ¼” deep which was about right, but should most likely be deeper for a thicker string material. Any number of notches is alright, but I would stick to an even number.
Remember this number will be divided by the large notch in the middle. The amount of notches is up to you – the more notches, the denser the string will be on the lamp.
I had 68 notches divided by the large notch – 68/2 = 34 above and below.
Step 7: Assembling
Assembling should be fairly straightforward. If you have cut the material correctly it should slot together snugly and securely with no glue.
If the lamp needs gluing you will need glue which is formulated for your material and I advise you following the manufactures direction especially when it comes to drying/curing times.
If the lamp parts are very loose hot glue may work very well for securing it together on most materials.
Step 8: Tying On/Off
I tied off and on with a conventional overhand knot secured with white glue so it was permanent, but if you are using fishing line you may want use something like a figure eight knot because an overhand knot will damage fishing like and cause it to fail.
It also helps if you put a small hole where you can tie on and off. If one were to take a single rib and make three holes – top, bottom, and middle – this will cover all the tying on and off.
Step 9: Stringing 1
This is where things get strange. For my shade there are seven ribs. Each rib has 68 notches plus one larger notch for the string. This is because when the lamp is strung you don’t want to have to tie off after each round.
So the string is tied on at notch 1 rib 1 (1/1) then goes to large notch 2 (L/2) then to 1/3 - L/4 – 1/5 – L/6 – 1/7 and then to L/1. This continues until you have filled all notches about the large notches, then you will tie off and begin again by flipping the shade upside down.
You cannot work from top to bottom because the layering of the string creating the interesting pattern will be lost. You can only work halfway through the lamp.
To create this up and down, little notch to big notch patter, one can only be achieved by having an odd number of ribs whether seven or however many you wish.
Step 10: Stringing 2
The simplest way to string is to tie on at the top (this is now notch 1/1) and work around (1/1 – L/2 - 1/3 - L/4 – 1/5 – L/6 – 1/7 – L/1) rotating the lamp on a table – so one is winding the string around the lamp until the middle is reached and then tied off.
Now turn the lamp upside down and begin again.
Reread the previous step if unsure.
Step 11: Finished!
I hope I have given enough information for you to make your own lamp. The ribs for this lamp must be made of an odd number, but other styles can be made with other configurations and I hope you will explore that with some inspiration from this instructable!
I really need to paint the base white and install the cord so I can turn it on.
Remember if you make some amazing stuff with a laser cutter please let me know I would love to feature it on my blog The Laser Cutter.