gr8sailor

Brewmeister, we have three different methods. You've outlined one. The easiest method is just to add scotch tape to the "light" side until it's balanced. Depending on the shape of the prop, we also added a bead of 5-minute Epoxy to the leading or trailing edges of the "light" side. When looking at the prop head-on, you could tell one of the blades was "bent" to either the left or right of the centerline (probably due to improper packaging).

At the moment we have a grand total of 36 boys who have picked-up their kits. We have already bought enough rubber bands to give them each 3 brand-new bands for competition day, and we have stressed to use them sparingly (use the kit bands for testing). I did a bunch of testing last evening, and found that as long as we lubricate the bands before racing we're getting 10 runs on our test rockets before we start running into band breakage (usually due to defects identified beforehand, which can be avoided). As far as winding...we have that taken care of too (as one of the online complaints was that the boys get tired of winding their rockets). I built a 4-position drill-powered winder, with an electronic counter for about $50. We're going to put 150 turns on all the rockets, and then let the boys wind them more or less from there. Brewmeister, we're actually using what I'd describe as "double-handled slalom ski rope"....completely home-brewed to hold the dowel, and hook onto the drill winder. Also with our latest testing, I've found that installing & balancing the prop is going to be "key" with these things. I did that with our most consistent "rocket" tester, and it consistently runs the full 40' length of the track. We went ahead and balanced the rest of the props, and now all the designs (including the bricks) are consistently hitting the 40' mark. We were noticing that when the rockets were initially taking-off, the ones that "vibrated" the most, were traveling the least distance. Sometimes releasing them "just right" would produce a good run...but then the next run would be pathetic. As far as running the races...we're definitely leaning toward running "race as ready" format. I'm just trying to figure-out if the Grand Prix Race Manager software can be configured in that format. I've been concentrating on getting the track and timing circuits working properly together, over how to actually run the races. Now that we have some time to step back and evaluate, this is definitely the next thing we're going to look at. Thanks for all the suggestions everyone, please keep them coming...it is a BIG help. :-D

Akecheta, Yes we are doing both of those suggestions with our rubber bands. I'll definitely take a look at that forum when I get a free moment, it was not coming up in any on-line searches. ScoutNut, Nobody in our district leadership has direct experience with the Space Derby. We're the first Pack even attempting it within the last 10 years. I had to talk to a "retired" Scout leader, who was the last person with direct experience, just to get our attempt off the ground. SeattlePioneer, I'll definitely put that in my notes. Sounds like lots of fun. The Council has a "Cub Scout Day" every year, and they had something very similar using 2-liter bottles and Bicycle pumps.

Hello, I'm an Assistant Cubmaster with my local Pack tasked with putting together our first-ever Space Derby. I'm hoping to get in contact with another adult leader who has actually tried to run this race, as we're running into an issue with our testing Rockets. We've put together a great adjustable length track, with electronic timing (compatable with our Pinewood Derby software), however these Rockets just refuse to fly consistently. The rubber bands that are coming with the kits are complete junk, so we've been experimenting with better rubber bands out of the following kit: http://www.scoutstuff.org/bsa/crafts/space-derby/accessories/rubber-bands.html The problem is, these rubber bands are about 1-2 inches longer than the kit rubber bands, so 100 winds is completely out the window. We have to wind these a minimum of 200 turns to go about 20 feet. We are consistently winding these 250 to 300 turns, and they are lasting about 10-15 races before we start to get breakage. That said, they are not always unwinding completely, and some are getting stuck after only going 10 feet with plenty of windings still left in the body. We have one test rocket that is your basic rocket (just google for pictures, and you'll find it), another that is a "wedge" design, then two "flying bricks" that are just taped together. There's more than enough power to drive any one of these rockets the full track length (as we've had the "flying bricks" win several test races). We're thinking that telling the boys to make the inner cutout wider before they glue their rocket body together is the solution, but we don't have a way to confirm this at the moment. One of our den leaders is working on another test rocket with completely open sides (so we can see what is going on with these rubber bands), but I wanted to get some thoughts from others on this issue.(This message has been edited by gr8sailor)