I'm looking for advice on where to put the shock cord mount on the lower airframe tube of my L3 certification bird - plain-vanilla design with a total loaded weight of just under 50lbs, 8" diameter G12 fiberglass and slightly over 12' tall. Two options:
1) Do what I did for my Level 2 rocket and place a couple of 3/8" U rings on either side of the forward-most centering ring of the motor mount.
2) I'm planning to use a CTI 98mm motor, and the forward end of the casing is tapped to accept a 3/8"-16 bolt 1" deep...I can get a nice forged bolt of the right dimensions from McMaster Carr.
By my calculations, both options would hold a shade over 1,000 dead pull, likely more than that in a dynamic tug. The single forged ring looks simpler and would avoid a few stress points in the drilled hole locations of the forward centering ring (although with generous epoxy I doubt that makes much diff), but...I don't see people doing it. Most of the builds I see on the forum use double U mounts.
Any thoughts?
1) Do what I did for my Level 2 rocket and place a couple of 3/8" U rings on either side of the forward-most centering ring of the motor mount.
2) I'm planning to use a CTI 98mm motor, and the forward end of the casing is tapped to accept a 3/8"-16 bolt 1" deep...I can get a nice forged bolt of the right dimensions from McMaster Carr.
By my calculations, both options would hold a shade over 1,000 dead pull, likely more than that in a dynamic tug. The single forged ring looks simpler and would avoid a few stress points in the drilled hole locations of the forward centering ring (although with generous epoxy I doubt that makes much diff), but...I don't see people doing it. Most of the builds I see on the forum use double U mounts.
Any thoughts?