Issue link: https://www.e-digitaleditions.com/i/1520252
e "Roto" in their name comes from the ability to spin the display around while in the console to access the small incandes- cent light bulbs used to illuminate the text. is made it possible to replace burned out bulbs without having to remove the unit or access it from the back of the panel. I think the Roto-Tellites look fantastic by allowing the text to be read without them lit, and then lighting from the back through filters, glowing different colors from their uniform white appearance when unlit. Credit goes to Chuck Penson for giving me the name of this device and helping me find the right font for the text, allowing me to recreate the exact appearance of real Ti- tan II equipment. To create the text, I print- ed black ink on transparency sheet, and cut them out to size. Prior to Chuck's intervening "enlighten- ment" (I couldn't resist), I was planning on having to build something from photos of a launch control center console. I had never even considered the possibility of finding real Roto-Tellites available. I found mine as "new old stock," in their boxes, on eBay from a seller in Israel. I retrofitted each callout to run on three 34 MAY/JUNE 2024 SPORT ROCKETRY volts, instead of the twenty-eight volts of the typical military equipment from the 1960s. is retrofit was accomplished with small board-mounted LEDs from Spark- Fun. e individual units, complete with appropriate resistors, are made to sew into clothing for creative projects like a bik- ing outfit with illuminated turn signals sewn right into the fabric. e LEDs come in strips of five units, attached together, which normally would be broken apart. I le mine together and wove and soldered a wire lead into each positive side, and an- other through the negatives, so they run in parallel. A little adjustment of the height of the strip by sanding made them fit just right into the old Roto-Tellites, which had corresponding slots cut into them using a Dremel. e arrangement worked out beautifully, with a nice, even row of LEDs right through the center of each little win- dow. Since model rocket flying is best when done in a group, this controller increases the enjoyment by allowing two people to take part in a launch. Each have to turn their required key. When flying with a bunch of kids, having two keys helps main- tain order and enhance the adventure, by Figure 7. Rear view of a Roto-Tellite display purchased off eBay. Figure 8. Roto-Tellite displays removed from housing and with my labels installed.