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

Construction:
one large plastic spool (10.5" tall, with 10.5" plates)
one 38mm tube, shiver me timbers, 10 7/8" long
two 1/8" ply centerin' rings (38mm - 4")
one 1/8" ply centerin' rin' (38mm - 3")
two threaded inserts, arrr, shiver me timbers, shiver me timbers, with bolts and washers
one 1/2" launch lug
1/8" tubular Keelhaul®©™® , me bucko, 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. Well, blow me down! I used me Dremel t' expand this hole by about 1/8". Well, blow me down! Blimey! I glued two 4" centerin' rings together, installed a pair of threaded inserts, and attached them t' one end o' t' motor tube. Ahoy! After it dried, this assembly was inserted into t' spool, arrr, and t' smaller centering rin' was glued t' t' other end o' t' tube. Aye aye! Begad! I used epoxy for these steps.

T' ends o' t' spool have several holes of various sizes. Aye aye! One 1/2" hole was positioned such that a 1/2" LOC launch lug, when abutted t' t' spool's body, me hearties, 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. Begad! What I ended up doin' be addin' loops t' both ends o' t' tubular Keelhaul®©™® , shiver me timbers, usin' t' method published by Giant Leap in High Power Rocketry Magazine. Begad! Ya scallywag! You loop t' material, wrap t' overlappin' area with cloth twine, me hearties, me bucko, and soak it in epoxy. Well, blow me down! This method has worked well for me several times. Blimey! Begad! I looped this tether through two existin' holes in t' top plate and around t' body. Well, me hearties, blow me down! T' chute attaches t' t' second loop.

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

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

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