When I made my Lamplighter FW fireworks show in December 2020 I had to decide how many fibers of different diameters could I fit into a Lamplighter 2 unit. This led me to do the following calculations. I think you may find them useful in planning how to use either a Lamplighter 1 or 2 on your layout and mix and match different diameter fibers.
First, I used an algorithm to determine what is the effective size of the Lamplighters 1 and 2. That may sound odd at first, but clearly there is space between fibers, even if they are nestled up as close as they can be, so just using the total area and dividing it by the area of the fiber will lead to an overestimation of the number of fibers that can fit. The effective area for the 2 Lamplighters is 22mm2 and 50mm2.
The chart below show you how many fibers of a specific size will fit into each. Next it was important to create a chart that allowed me to mix and match fibers for the fireworks. The center used 2 of 2mm fibers, the next ring used 6 of 1.5mm fibers, next 12 of 1mm fibers, then 24 of 0.75mm fibers. The optics used was the based on the Lamplighter 2 unit so I used 50mm2 as the effective area for the optical cavity.
Now I could calculate the number of different fibers I could put into the Lamplighter FW, as shown below.
Incidentally, the Lamplighter FW we created used 3 of the Lamplighter 2 optical cavities, so we could have had a total of 270 fiber lights. Just imagine wiring up 270 LED’s for this project!! In actual fact, I felt we had enough light spread without the 0.5mm fire ring, so I left them off.
The coloration of the fibers was all done with the Tamiya translucent paints.
To see the final result, see the fireworks video: