KevinM
Well-Known Member
- Joined
- Sep 4, 2009
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Okay, I admit it: Maybe this wasn't such a good idea after all...
Last year I decided to take a crack at building a dual-deploy configured rocket. I mod'ed an Estes Leviathan by following some of the "zipperless" mods that other folks have done (to implement a break-point at the bottom of the main section of body tube) and then built an e-bay that sits half-way down the main body tube. It's a pretty standard config beyond that with the main chute in the upper section above the e-bay. All-in-all it's come together well, but the first time I flew in the DD config the parachute deployed at apogee instead of on the way back down when it was supposed to. (The chute eject charge was heard on the way down, the nose cone just didn't hold the laundry in when the apogee charge went off.) No damage was done, and the rocket actually landed really close to the pad despite the early deployment, but that wasn't how it was supposed to work...
My plan from day one was to friction-fit the nosecone, but having read many posts on this forum about DD it seems that there's a definite preference to using shear pins. (For obvious reasons I'm sure.) Is friction-fitting the nosecone on a DD config a fools errand, or is there a reasonable chance of getting it right? I'm not opposed to exploring a more conventional (shear pin) solution, after all I'm sure there's a preference to doing it that way for a reason, but I'd like to try to stick with what I've done if I can.
Has anyone used shear-pins with medium-thickness cardboard tubing? (I'm not sure how best to describe the thickness of Leviathan's tube - it's definitely thicker than standard Estes tubing, but still not as thick as my LOC Weasel.) If I soak the cardboard in CA will it give it enough hardness that a couple of 2-56 nylon pins will shear cleanly, or am I still as likely to tear the tube as I am to shear the pin?
Any thoughts?
Last year I decided to take a crack at building a dual-deploy configured rocket. I mod'ed an Estes Leviathan by following some of the "zipperless" mods that other folks have done (to implement a break-point at the bottom of the main section of body tube) and then built an e-bay that sits half-way down the main body tube. It's a pretty standard config beyond that with the main chute in the upper section above the e-bay. All-in-all it's come together well, but the first time I flew in the DD config the parachute deployed at apogee instead of on the way back down when it was supposed to. (The chute eject charge was heard on the way down, the nose cone just didn't hold the laundry in when the apogee charge went off.) No damage was done, and the rocket actually landed really close to the pad despite the early deployment, but that wasn't how it was supposed to work...
My plan from day one was to friction-fit the nosecone, but having read many posts on this forum about DD it seems that there's a definite preference to using shear pins. (For obvious reasons I'm sure.) Is friction-fitting the nosecone on a DD config a fools errand, or is there a reasonable chance of getting it right? I'm not opposed to exploring a more conventional (shear pin) solution, after all I'm sure there's a preference to doing it that way for a reason, but I'd like to try to stick with what I've done if I can.
Has anyone used shear-pins with medium-thickness cardboard tubing? (I'm not sure how best to describe the thickness of Leviathan's tube - it's definitely thicker than standard Estes tubing, but still not as thick as my LOC Weasel.) If I soak the cardboard in CA will it give it enough hardness that a couple of 2-56 nylon pins will shear cleanly, or am I still as likely to tear the tube as I am to shear the pin?
Any thoughts?