3 months 4 weeks ago - 3 months 4 weeks ago#8888by Daniel Tyszka
I calculated the Cp using a spreadsheet based on the Barrowman equations, accounting for the fact that the motor sticks out the back end by 0.46"
With this method, Cp was 23.15" from the tip of the nose cone
Needed a 14.25g nose weight on my rocket to get acceptable stability margin. I used a lead fishing sinker hung from the loop at the bottom of the nose cone for the weight.
Note that the Cp and weight quoted above are for the Estes # 3226 Hi Flier XL. Your weight may end up being a little different than mine, as I also made a few modifications to the kit (heavier shock cord, steel leader motor mount). But you'll almost certainly need a good lump of mass near the nose to ensure stability, esp with the E motors
Last Edit: 3 months 4 weeks ago by Daniel Tyszka. Reason: Corrected typos
I have actually been working on some winter projects this year, all pretty much scratch designs.
- My "Heart Healthy Breakfast" (HHB). Constructed out of 2 2lb Quaker Oats round containers, 1 1lb 14oz Quaker Steel Cut Oats round container. I scanned one side of a Quaker Oats 5lb box and printed out on heavy paper to both make a transition from the bottom containers to the steel cut oats container and to cover the 4 basswood fins. It has a 29mm stuffer tube and a custom made nose cone made in part from the bottom part of a plastic two part Easter Egg I got at Michaels or Hobby Lobby. No paint was harmed in the making of this rocket!
- A traffic cone odd rock. Found traffic cones that can also be used as sand box toys at the Dollar Store. Just added an 18mm motor tube and launch lug and glued/epoxied it all together.
- Also finally started working on my planned "Nut Job", similar in concept to the HHB with a 38mm motor mount/stuffer tube, 3 plywood fins (painted with Almond color enamel paint) with the main body consisting of multiple Planters Cashew Lovers Nut cans. The nose cone is custom made from a second one of the traffic cones, and a boat tail made from the top portion of the Easter Egg. Should all be ready for the opening launch of the season.
3 months 16 hours ago - 2 months 4 weeks ago#8947by Frank DeAngelo
I bought a Hy Flier XL on Amazon. It took forever to get delivered. I should have bought it at the Hobby Lobby in Tyngsboro. It is a great kit that I have wanted for a long time. It was fun to build. It was a bit of a challenge to glue the fins on nice and straight because they are so big. The MMT can accommodate 24mm motors. Hopefully we will have nice weather someday so that I can paint it. I noticed on the CMASS Forum mention of purchasing kits to raise money for the Bill Spadafora memorial fund. They have a D Region Tomahawk for only $20 which is a steal.
Last Edit: 2 months 4 weeks ago by Frank DeAngelo.