Hey guys-
I'm working up a scratch build 2.5" / 38mm using reefed main parachute dual deployment. Regarding the SC mount. I won't be able to get my hand down in there. But I'm really big into maintainability. So that rules out tying to an eye bolt and gluing to the MMT. I don't want to make an airframe joint just for this as I'm going for KISS. Here's what I came up with and would like some feedback.
Drill two holes in each CR. Fish the SC down to the aft end of the rocket, around the aft CR and back up. Out the top of the rocket and tie it off with a figure-8 or similar high efficiency knot. Tape over the aft lacing, use well nuts or somehow keep it out of the slipstream.
Benefits-
To switch out the SC, untie it and fish in a new one. The force is focused on the aft CR between the MMT, BT and fins- a VERY strong area already. The CR holes relive pressure in the main compartment- doubling as pressure a equalization port. Eyebolt assy and epoxy cost and mass are eliminated in favor of an extra foot or two of shock cord. The step can be done at any point in assembly.
Drawbacks-
Shock cord may shake loose and get caught in a mach 5 exhaust jet! Certainly there is an elegant way to mitigate this.
Holes in the CRs may reduce the effectiveness of separation charge. Well nuts will solve this issue for free.
Open for critical thought. And I sure would like to know if anyone has done this before (7 billion people on the planet today, being FIRST is getting hard!)
I'm working up a scratch build 2.5" / 38mm using reefed main parachute dual deployment. Regarding the SC mount. I won't be able to get my hand down in there. But I'm really big into maintainability. So that rules out tying to an eye bolt and gluing to the MMT. I don't want to make an airframe joint just for this as I'm going for KISS. Here's what I came up with and would like some feedback.
Drill two holes in each CR. Fish the SC down to the aft end of the rocket, around the aft CR and back up. Out the top of the rocket and tie it off with a figure-8 or similar high efficiency knot. Tape over the aft lacing, use well nuts or somehow keep it out of the slipstream.
Benefits-
To switch out the SC, untie it and fish in a new one. The force is focused on the aft CR between the MMT, BT and fins- a VERY strong area already. The CR holes relive pressure in the main compartment- doubling as pressure a equalization port. Eyebolt assy and epoxy cost and mass are eliminated in favor of an extra foot or two of shock cord. The step can be done at any point in assembly.
Drawbacks-
Shock cord may shake loose and get caught in a mach 5 exhaust jet! Certainly there is an elegant way to mitigate this.
Holes in the CRs may reduce the effectiveness of separation charge. Well nuts will solve this issue for free.
Open for critical thought. And I sure would like to know if anyone has done this before (7 billion people on the planet today, being FIRST is getting hard!)
