XENON STROBE

At night launches, my grandson and I get asked frequently where we got our Xenon strobe lights. They’re super bright, 1 second pulse rate and seem to survive repeated launches, recovery and even crashes. The answer is, we build them. They represent some minor modifications to available electronic kits and pretty simple body tube/nose cone rework.

We start with part# CPS-163 12V Xenon Flasher Kit from www.electronics123.com priced at $17.67 plus shipping. Schematic, parts list and instructions are available at www.kitsrus.com if you want to hunt down your own parts and try to save a few bucks. During the kit build, make a few minor changes. Substitute a 1.2MegOhm resistor for the flash rate pot (produces 1 second rate and saves space and weight). Add a Radio Shack 9V battery connector. Bend the Xenon lamp leads and mount the lamp projecting past the end of the P/C board. Substitute a jumper wire or slide switch for the 1 Amp fuse and fuse holder. The fuse is unnecessary and a switch is often useful although plugging in the 9V battery is an adequate switch in many cases. After assembly and test, we usually mount the P/C board to the body tube with metal spacers.

Installation in the airframe is dependant on the type of rocket. In medium power rockets, we have tended to modify and install in the nosecone. In high power rockets with a cargo bay, that is the preferred location. In either case a 3” long piece of Acrylic tubing (Tap Plastics) near the diameter of the body tube is required. We have machined the Acrylic in some cases to act as a coupler tube with about 1” of engagement in each mating body tube. A tablespoon of liquid dish soap in a quart of water makes an excellent coolant to allow smooth machining of the Acrylic. In some nosecone installations we simply cut the nosecone at a diameter that accommodated the size of the Acrylic tube. Acrylic does not bond well with standard epoxy, but Devcon has a two part plastic epoxy that melts and bonds with the Acrylic. Whether machined or sanded, the parent tube should be shortened by about 1” and the Acrylic installed to provide about a 1” long window. To permit access, we usually leave one end of the Acrylic tube unglued and attach with removable Nylon rivets part# HDWE-RVT-NAT, $2.95 per bag of 24 in the hardware section at www.publicmissiles.com