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| PACK 1703 |
| Leonard Elementary School - Troy Michigan |
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| Space Derby Tips Please bring 2 extra rubber bands to pre-registration! ˇ Lighter is definitely better. There is a limited amount of force and energy in two (2) rubber bands wound 100 times so minimizing the mass of the unit can only help. We've seen a number of winners and the shapes of those winners differ dramatically. One thing in common with both of them is their weight. Both were very light and well balanced. The key is making it light without removing so much material that the winding of the rubber bands actually splits the ship in two or causes serious cracking. That's happened to potential winners for both of the last two years and the kids are pretty upset when it does. ˇ The shape is not the key. We have seen a number of different shapes and the winners were very different. One was cigar-like while the other was more like a KlingonŽ vessel (from Star TrekŠ). A lot of shuttle look-a-likes have been used and various other configurations. As long as the vehicle is symmetrical and light then it seems to perform well. ˇ No glue on the propeller assembly. Never use glue on the propeller assembly. Other than the fact that you may slip a bit and get some glue on the prop itself or on the bushing underneath, if you break a rubber band you have to be able to remove the propeller. During the Space Derby this year we had a number of problems including the rubber bands breaking during the winding and the actual propeller breaking. If that happened to a space vehicle where the assembly were glued in place it would have much more difficult to replace. ˇ Make sure the propeller is on correctly. Several Space vehicles this year had the propellers on backwards. When looking at the hub (center) of the propeller closely, there will be rounded end and a rougher end that is not even. The rounded end goes towards the rocket ship and should be touching the small metal bushing. The rougher end has a little protrusion that is designed to catch the wire when it is bent over. Which leads to the next tip... ˇ Don't cut the bent over wire too short. In the attempt to be neat do not cut it too short and then during the winding, the propeller can slip and spin around. Leave a little more than you think is necessary and you should be fine. Just bend it over to form an inverted 'U', with plenty to grab the prop, and then there should be no trouble. ˇ Make sure the red plastic liner covers the entire hook. The red plastic sleeve that slips over the metal hook (on the inside of the propeller assembly) MUST be put in place. That is there to prevent the metal hook from cutting through the rubber bands during the winding. It sometimes takes a little effort to pull it all the way on but it can be done. You can always grab the end of the wire with some pliers and work it on slowly, but make sure it goes all the way to the end of the hook. ˇ Don't glue in the tail unit that holds the rubber bands in place. Basically for the same reason. The rubbers bands can't be altered in any way without disassembling the unit. This actually happened to one Scout's vehicles and repairs were difficult. ˇ The tail unit needs notches to prevent spinning. After you are all done with your space ship make sure there are two depressions, of 'V's cut into the tail to prevent the end unit from spinning during the winding or once the rubber bands start to unwind. It may wind up okay but when the pressure is released slightly it may start to spin. If you cut them to deep you will be essentially shortening the spaceship and decreasing the pull on the rubber bands. It's more of a trial and error type thing. Start shallow and increase as needed. ˇ Various fin/wing sizes and configurations work. We personally haven't had a lot of luck in this department - I guess I have to read up on my aerodynamics. What I've seen is winners with small fins all over the ship (Kevin) and winners with just two big wings and a tail like the space shuttle (Jake) . The bigger wings seem to cause less spinning when the ship is released for a more level flight, while the smaller fins seem to allow the ship to carry its speed a bit better. The bottom line is they both seem to work if everything else is done right. My personal opinion is that the bigger wings seem a bit better but you'll have to figure that one out on your own. Why we keep using the small fins is a mystery to me. ˇ Have fun. Remember, it's only a game and this is for fun. |