Reference / Paper · 2008
Peak of Flight #223: Build a triangulation scope
Apogee Components' Peak of Flight newsletter, issue 223 (2008-12-02).
- peak-of-flight
- apogee-components
- model-rocketry
Reference / Paper · 2008
Apogee Components' Peak of Flight newsletter, issue 223 (2008-12-02).
Apogee Components' Peak of Flight newsletter, issue 223 (2008-12-02).
Build a Triangulation Scope Use it to find out where your rocket landed. The 3-engine cluster Semroc Defender rocket kit: http://www.apogeerockets.com/Semroc_Defender.asp Apogee Components, Inc. — Your Source For Rocket Supplies That Will Take You To The “Peak-of-Flight” 3355 Filmore Ridge Heights Colorado Springs, Colorado 80907-9024 USA www.ApogeeRockets.com e-mail: [email protected] ISSUE 223 DECEMBER 2, 2008 Build A Triangulation Locator Scope By Tim Van Milligan In the last Peak-of-Flight newsletter (www.ApogeeRockets.com/education/downloads/Newsletter222.pdf), I showed you how to use triangulation to find you rocket. The key piece of equipment was two “triangulation locator scopes.” In this article, I’ll show you how to build them. Don’t worry, this isn’t going to be hard. I believe in simple and inexpensive. Building Supplies: 1) 1/2” thick plywood: You’ll only need a piece about 81/2 inches in diameter for each scope, but it is not necessary that the base be round. 2) 1/4 inch diameter X 3/4 inch long hardwood dowel for the pivot 3) Spruce wood strip: 1/2 X 1/4 X 8-1/4 inches 4) Two small nails or thick music wire. 5) 1/4”-20 X 5/16” Tee Nut (sometimes also called a blind nut). 6) Clear plastic cover from a CD-ROM jewel-case 7) Camera tripod Photo 1: Using a tracking scope like this one allows you to fix the position of the rocket by triangulation. Tools: 1) Electric drill 2) Drill bits: 5/16”, 1/4”, and a small drill bit that is the same diameter as your small nails or music wire. 3) Wood glue 4) CA glue 5) Permanent marker 6) Ruler 7) Hammer 8) Razor saw to cut the dowel 9) Pin-vise to hold tiny drills 10) Sandpaper Base Assembly Steps 1. I cut my plywood base using a jig-saw. As mentioned in the supplies, your base does not have to be circular. It is more convenient if it is, because the handle of the gun-sight will hang over the edge and will be easier to rotate. As you can see from my photos (Photo 3), I used the cheap particle-board wood for my base because I had a big scrap piece that didn’t cost me anything. I would recommend real plywood. The particle-board chips easily, and it is hard to drill a round hole through it. But in a pinch, it will work Photo 2: Simple tools, like those shown, are all it takes to put together this precision instrument. About this Newsletter Continued on page 3 Newsletter Staff You can subscribe to receive this e-zine FREE at the Apogee Components web site (www.ApogeeRockets.com), or by sending an e-mail to: [email protected] with “SUBSCRIBE” as the subject line of the message. Page 2 2. Drill a 5/16-inch diameter hole to accept the shank ISSUE 223 Writer: Tim Van Milligan Layout / Cover Artist: Tim Van Milligan Proofreader: Michelle Mason DECEMBER 2, 2008 Continued from page 2 Build a Triangulation Locator Scope The side you insert the teenut into will be the bottom of the base. Center Tee nut Photo 3: Bottom side of the wooden base plate. Note that the Tee nut is placed off-center. of the tee-nut. Don’t put the hole in the exact center of the wood. Put it off-center about 1 inch. You’ll be drilling another hole in the exact center later on for the pivot of the gun-sight. 3. Using the hammer, pound the tee-nut into the hole. 4. Print out the protractor guide from the download of printouts. It can be found at: at: http://www.ApogeeRockets.com/education/ downloads/triangulation. zip. Cut it out, and glue it centered on the top-side of the base using wood glue. Allow the glue to dry thoroughly. If you don’t let it dry, the hole you drill in the next step will be off-center (been Photo 4: Tee nuts can be there, done that). found at hardware stores. A four-pack costs about a $1. 5. After the glue has dried, drill a 1/4 inch hole as marked through the exact center of the protractor rosette. At this point, the base is done. Gun-Sight Assembly Steps 6. Before cutting the strip of wood to make the gunContinued on page 4 Available Online & Worldwide through Quality Hobby Shops & Online Retailers Trust Sunward for a complete line of Model Rocket Kits and Parts including: Tubes, Baffles, Connectors, Mounting Kits, Balsa & Plastic Nose Cones, Nylon Parachutes, motor cluster cables, and NOMEX flame resistant blankets and shock cord protectors. NOW AVAILABLE FROM APOGEE ROCKETS! Browse online our large lineup of BT50, BT56, BT60, and BT70 based Model Rockets Kits. www.sunward1.com [email protected] Direct 416-953-1847 fax 416-245-7985 ISSUE 223 DECEMBER 2, 2008 Page 3 Continued from page 3 Build a Triangulation Locator Scope the center of the short end of the strip of wood. Put it in the exact center of the end, as this will be the pointer location. sight base, measure and mark the pivot point location. It should be 3-1/4 inches from one end. Drill a 1/4-inch hole through the strip of wood at this point. Be careful, since the strip of wood is only 1/2 Photo 5: Finished base. inches wide, it can easily crack in half at the point of the hole. That’s why I suggest you don’t cut it to length yet. If it cracks off, you haven’t wasted the whole piece. You can simply cut it off and start drilling a new hole. Again, I’m saying this from experience. 11. On the Photo 6: A pin-vise is a special tool long end of that holds small drill bits. the gun-sight base, pound in a small nail about 1/4 inch from the end of the wood on the top surface. This will be the back sight, and also a handle that you can use to turn the gun-sight on the base. 12. From an old CD-ROM jewel case, cut a rectangular piece of clear plastic that is 1-1/4 inches wide by 3-1/2 inches long. You can cut it by scoring it with a hobby knife and then bending the plastic back and forth. It will snap off pretty easily. Sand the edges and corners smooth. 7. After the hole is drilled into the gun-sight base, cut the strip of wood to length: 8-1/4 inches. 8. From the 1/4-inch diameter dowel, cut a short length of dowel that is 3/4-inch long. Glue this into the hole in the strip of wood using wood glue. The dowel should be flush with one surface of the wood. This will be the top surface. 13. Draw a centerline down the length of the clear piece of plastic with the permanent marker. 9. Draw a centerline down the entire length of the strip of wood using the marker. Extend it down the end caps of the wood. 10. Using a tiny drill in a pin-vise, create a small hole in 14. Temporarily position the plastic piece on the end of the gun-sight base. The bottom edge of the plastic should be flush with the bottom surface of the gun-sight base. Make sure the centerlines of the two pieces are aligned. Then mark the position of the hole on the plastic piece. Us- Model Rocket Design and Construction By Timothy S. Van Milligan New 3rd Edition Now Shipping! This new 328 page guidebook for serious rocket designers contains the most up-to-date information on creating unique and exciting models that really work. With 566 illustrations and 175 photos, it is the ultimate resource if you want to make rockets that will push the edge of the performance envelope. Because of the number of pictures, it is also a great gift to give to beginners to start them on their rocketry future. For more information, and to order this hefty book, visit the Apogee web site at: www.ApogeeRockets.com/design_book.asp Apogee Components 3355 Fillmore Ridge Heights Colorado Springs, Colorado 80907 USA telephone: 719-535-9335 website: www.ApogeeRockets.com Page 4 ISSUE 223 DECEMBER 2, 2008 Continued from page 4 Build a Triangulation Locator Scope It should spin freely. Sand the dowel if the fit is too tight. Also, the dowel should not protrude through the base of the plywood. Sand it shorter if it is too long. The gun-sight can be removed from the base so that it isn’t broken during transport to and from the launch field. Forward sight: Clear plastic from a CD-ROM jewel case Rear post: music wire or small nail. 17. You will need two tracking scopes, so go ahead and build the other one using the same steps. Base: 1/4” X 1/2” X 8” long wood 18. When you’re ready to launch rockets, attach the base to a tripod using the Tee nut on the bottom surface of the base. Pointer 19. See the “how-to” instructions in Peak-of-Flight newsletter #222 to learn how to track your rockets. Pivot post: 1/4” dowel Conclusion Photo 7: Gun-sight is made from common hobby-shop materials. Building this triangulation tracking scope is fairly easy and cheap. I had all the materials lying around my workshop except the Tee-nuts. In total, I spent 98 cents for a pack of four at Home Depot. I also happen to have two camera tripods sitting around. But if you don’t, you can find these used at pawn shops or at garage sales for less than $10. I really like cheap projects! ing the pin-vise and the drill, make a small hole in the clear plastic piece. 15. Glue a short piece of music wire into the hole on the end-cap of the gun-sight base using CA glue. It should stick out about 1/2-inch. Then glue the clear plastic piece on the end, with the pointer protruding through the hole in the plastic. About The Author: Tim Van Milligan (a.k.a. “Mr. Rocket”) is a real rocket scientist who likes helping out other rocketeers. Before he started writing articles and books about rocketry, he worked on the Delta II rocket that launched satellites into orbit. He has a B.S. in Aeronautical Engineering from Embry-Riddle Aeronautical University in Daytona Beach, Florida, and has worked toward a M.S. in Space Technology from the Florida Institute Completed triangulation scope. of Technology in Melbourne, Florida. Currently, he is the owner of Apogee Components (http://www.apogeerockets.com) and the curator of the rocketry education web site: http://www.apogeerockets.com/education/. He is also the author of the books: “Model Rocket Design and Construction,” “69 Simple Science Fair Projects with Model Rockets: Aeronautics” and publisher of a FREE e-zine newsletter about model rockets. You can subscribe to the e-zine at the Apogee Components web site or by sending an e-mail to: ezine@apogeerockets. com with “SUBSCRIBE” as the subject line of the message. 17 0° 18 0° 17 0° 16 0° 0° 16 0° 90 80 ° 70 ° 60 ° ° 50 ° 40 30 ° ° 20 10 ° 0° 10 ° ww 20 ° w. Ap 30 ° og ° 1 ee 40 ° Ro ck et s. 00 ° 1 10 1 ° 2 co m R 1 14 0° 30 0° ° 15 0° 90 ° ° 70 ° 8 0 50 60 ° ° 15 14 0° 13 0° 12 0° 10 0° 11 0° 16. Test fit the dowel on the base of the gun-sight into the central hole on the base of the protractor rosette. ISSUE 223 DECEMBER 2, 2008 Page 5 How Creative Can Your Designs Get? Test The Limits Of Your Creativity In The NEW RockSim v9! RockSim, the leading software for designing and finding out how high rockets will fly, is now even more versatile. You asked for these new features, n External Pods and we listened: n Parallel Staging Attach Fins to Fins Scale Your Designs Up/Down n Automatic Downloads of New Engine Files n n Authentic images taken from RockSim v9. Just imagine the really cool designs you’ll make! www.RockSim.com Space Foundation certified as an excellent teaching aid. For further information, call Apogee Components at: 719-535-9335. • Securely holds the engine, preventing it from being spit out at parachute deployment • Gives your rocket a professional and finished look • Great for reloadable motors • Easy to install • Made from two-piece, machined aluminum • No tools required to swap out rocket motors between flights • We stock retainers for 29 & 38mm motors. Other sizes available on request. www.ApogeeRockets.com/retainers.asp Page 6 ISSUE 223 DECEMBER 2, 2008 www.ApogeeRockets.com Aero Pack Motor Retainers