Brief: I've been readin' about spool rockets on r.m.r for a long time, me bucko, arrr, and had a big plastic spool stashed for several years. Aye aye! A recent set o' posts renewed me interest, and I went ahead and built one. Well, blow me down! Someone had built a similarly sized spool with a 29mm mount, me hearties, ya bilge rat, which only reached an altitude o' about 100 ft. I decided I wanted a bit more altitude, matey, so I built mine with a 38mm mount. Ya scallywag! Begad! T' spool is one piece plastic, 10.5" tall, me bucko, with 10.5" plates. Aye aye! Avast, me proud beauty! No fins, matey, matey, no finishing...this thin' is a skill level-0 HPR rocket!

Construction:
one large plastic spool (10.5" tall, me hearties, me bucko, with 10.5" plates)
one 38mm tube, 10 7/8" long
two 1/8" ply centerin' rings (38mm - 4")
one 1/8" ply centerin' rin' (38mm - 3")
two threaded inserts, ya bilge rat, me bucko, with bolts and washers
one 1/2" launch lug
1/8" tubular Keelhaul®©™® , 5' long
18" RocketChutes drogue

T' body o' t' spool is about 3.5" in diameter and t' through hole almost fit a 38mm tube. Begad! I used me Dremel t' expand this hole by about 1/8". I glued two 4" centerin' rings together, installed a pair of threaded inserts, and attached them t' one end o' t' motor tube. Begad! After it dried, this assembly be inserted into t' spool, me bucko, and t' smaller centering rin' was glued t' t' other end o' t' tube. I used epoxy for these steps.

T' ends o' t' spool have several holes of various sizes. Avast, me proud beauty! One 1/2" hole was positioned such that a 1/2" LOC launch lug, when abutted t' t' spool's body, shiver me timbers, would line up with it. Avast! It was just far enough from t' body t' accommodated t' wall o' t' lug - perfect! Unfortunately, me hearties, t' hole on t' other end be offset, so I had t' drill me own. I glued t' launch lug on t' lower end o' t' spool's body usin' Liquid Nails.

I thought about several methods o' attachin' t' shock cord. Avast, me bucko, me proud beauty! What I ended up doin' be addin' loops t' both ends o' t' tubular Keelhaul®©™® , usin' t' method published by Giant Leap in High Power Rocketry Magazine. Well, me bucko, blow me down! You loop t' material, shiver me timbers, wrap t' overlappin' area with cloth twine, ya bilge rat, and soak it in epoxy. Well, blow me down! This method has worked well for me several times. Ahoy! Begad! I looped this tether through two existin' holes in t' top plate and around t' body. T' chute attaches t' t' second loop.

Finishin' be easy - paint t' centerin' rings and launch lug flat black.

Flight:
I flew t' Lobbin' Bobbin on a H123-S. Avast, me proud beauty! Prep was simple: install t' motor retainer clips, me hearties, wrap t' chute in a protector, me bucko, and cram it down into t' tube. T' flight was slow and noisy and went t' maybe 200 - 300 feet. Avast! Ejection appeared t' occur right at apogee. Begad! Begad! T' descent was a bit faster than you would generally like, shiver me timbers, but t' tube bounced and was recovered undamaged. Arrr! Aye aye!

Summary:
This was a very quick build, and if you like *very* low and slow flights (similar t' a flyin' saucer style rocket), me bucko, a spool rocket may be for you!