Hi folks-
Working on a new scratch build and wanted to get folks to weigh in on a question I'm pondering: What is the minimum overlap you should design for a body tube & coupler? I'm thinking HPR, in case that changes anything. Normally I'd like to see ~1 body diameter of separable overlap, but when you start getting into 4" tubing, the largest coupler I'm finding is ~6-8", which (for those of us who can't do math) means you're less than 1 diameter if you split it in half. Note: these are cardboard tubes... haven't ventured too far into FG, etc.
This becomes even more of a problem if I'm looking at making the coupler into an e-bay with a vent band. scratch 1/2-1" of length for "vent/switch band" duties. with a 6" coupler, I'm down to 2.5" of overlap on either end, which doesn't make me feel overly comfortable when shoving a K1275 up the pipe. Even if it's a 8" coupler, I'm still looking at only 3.5" overlap. Yes, I could build an e-bay from multiple couplers, but I'd like to avoid that if possible (although that appears to be how others accomplish this... e.g. Binder Design).
if you have DD rockets (scratch or kit), can you let me know how the coupling around the e-bay is accomplished & how much overlap you have?
Appreciate the help!
Erik
Working on a new scratch build and wanted to get folks to weigh in on a question I'm pondering: What is the minimum overlap you should design for a body tube & coupler? I'm thinking HPR, in case that changes anything. Normally I'd like to see ~1 body diameter of separable overlap, but when you start getting into 4" tubing, the largest coupler I'm finding is ~6-8", which (for those of us who can't do math) means you're less than 1 diameter if you split it in half. Note: these are cardboard tubes... haven't ventured too far into FG, etc.
This becomes even more of a problem if I'm looking at making the coupler into an e-bay with a vent band. scratch 1/2-1" of length for "vent/switch band" duties. with a 6" coupler, I'm down to 2.5" of overlap on either end, which doesn't make me feel overly comfortable when shoving a K1275 up the pipe. Even if it's a 8" coupler, I'm still looking at only 3.5" overlap. Yes, I could build an e-bay from multiple couplers, but I'd like to avoid that if possible (although that appears to be how others accomplish this... e.g. Binder Design).
if you have DD rockets (scratch or kit), can you let me know how the coupling around the e-bay is accomplished & how much overlap you have?
Appreciate the help!
Erik
