Hmmm, so where did that 43.75 inch location for the Forward Rail Button come from? It started with my consideration of the longest motor which I will be installing in the rocket. I will NOT be installing a CTI 98mm 6XL Grain motor or an AT 98mm 18000 / 20480 motor. They could fit, but it's my perception, using the "bang for the buck" theory, specific to this rocket, that a CTI 98mm 6-Grain or AT 98/15360 will make me happy. I already have a CTI 75mm 6XL Grain Motor Case, which is 42.25" in length. A CTI 98mm 6-Grain Motor case is 42.21" in length, and an AT 98/15360 case (and hardware) is 41.711" in length. Also, the Motor Retainer positions the thrust face of the motor exactly 0.75" back from the Thrust Plate. So, I am prepared to assemble the Drogue Shock-Cord Tether Platform exactly 41.75" from the backface of the Thrust Plate. That dimension will apply specifically to the bottom of the plywood centering ring, part of the platform. The total components to consider in this assembly, which make up the complete Tether Platform are;
1. Stop Ring (coupler diameter x 1/2" width), which will sit below (aft end direction) the plywood centering ring.
2. Plywood Centering Ring (6" OD x 75mm ID x 1/4" thickness).
2. FG Bulkplate (6" OD x 1/8" thick), which sits directly above (forward end direction) the plywood centering ring, which it is J-B Weld adhered against..
3. Stop Ring (coupler diameter x 1 1/8" width, which will sit directly above the FG Bulkplate. The design intent of this ring is to help absorb the forces applied by the Drogue Shock-Cord during apogee ejection.
I usually place the forward Rail Button exactly 1/3 of the length of the total rocket, from the base. In this case that would be 43.31". Hmm, interesting, that just happens to be exactly where components for the Tether Platform will be mounted. I thought about placing it below (aft direction) the Tether Platform. What if it requires some type of service / repair on the inside. NO ACCESS! Ok, it will be placed above (forward end) the Tether Platform, after those components are assembled. Specifically at 2.00" above the bottom of the plywood centering ring. Sure, it's a little further up the rocket than I would normally choose, but it's the best compromise in this situation.
Even though I know, and have marked the location, it is too early to drill the hole for the forward rail button.
1. Stop Ring (coupler diameter x 1/2" width), which will sit below (aft end direction) the plywood centering ring.
2. Plywood Centering Ring (6" OD x 75mm ID x 1/4" thickness).
2. FG Bulkplate (6" OD x 1/8" thick), which sits directly above (forward end direction) the plywood centering ring, which it is J-B Weld adhered against..
3. Stop Ring (coupler diameter x 1 1/8" width, which will sit directly above the FG Bulkplate. The design intent of this ring is to help absorb the forces applied by the Drogue Shock-Cord during apogee ejection.
I usually place the forward Rail Button exactly 1/3 of the length of the total rocket, from the base. In this case that would be 43.31". Hmm, interesting, that just happens to be exactly where components for the Tether Platform will be mounted. I thought about placing it below (aft direction) the Tether Platform. What if it requires some type of service / repair on the inside. NO ACCESS! Ok, it will be placed above (forward end) the Tether Platform, after those components are assembled. Specifically at 2.00" above the bottom of the plywood centering ring. Sure, it's a little further up the rocket than I would normally choose, but it's the best compromise in this situation.
Even though I know, and have marked the location, it is too early to drill the hole for the forward rail button.
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