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! Begad! A recent set o' posts renewed me interest, and I went ahead and built one. Avast, me proud beauty! Someone had built a similarly sized spool with a 29mm mount, matey, ya bilge rat, which only reached an altitude o' about 100 ft. Avast, me proud beauty! Begad! I decided I wanted a bit more altitude, me bucko, so I built mine with a 38mm mount. Begad! T' spool is one piece plastic, 10.5" tall, me hearties, with 10.5" plates. Ahoy! Well, shiver me timbers, blow me down! No fins, me hearties, me hearties, 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, 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, with bolts and washers
one 1/2" launch lug
1/8" tubular Keelhaul®©™® , shiver me timbers, 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. Blimey! I used me Dremel t' expand this hole by about 1/8". Begad! I glued two 4" centerin' rings together, installed a pair of threaded inserts, shiver me timbers, and attached them t' one end o' t' motor tube. Begad! After it dried, ya bilge rat, this assembly was inserted into t' spool, and t' smaller centering rin' was glued t' t' other end o' t' tube. Avast! Avast, shiver me timbers, me proud beauty! I used epoxy for these steps.

T' ends o' t' spool have several holes of various sizes. Ya scallywag! Blimey! One 1/2" hole be positioned such that a 1/2" LOC launch lug, arrr, when abutted t' t' spool's body, would line up with it. Well, blow me down! Blimey! 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 was offset, arrr, 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. What I ended up doin' was addin' loops t' both ends o' t' tubular Keelhaul®©™® , shiver me timbers, usin' t' method published by Giant Leap in High Power Rocketry Magazine. You loop t' material, wrap t' overlappin' area with cloth twine, matey, shiver me timbers, and soak it in epoxy. Aye aye! Begad! This method has worked well for me several times. Avast, me proud beauty! I looped this tether through two existin' holes in t' top plate and around t' body. Begad! 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! Prep was simple: install t' motor retainer clips, matey, me hearties, wrap t' chute in a protector, and cram it down into t' tube. T' flight was slow and noisy and went t' maybe 200 - 300 feet. Begad! Ejection appeared t' occur right at apogee. Ya scallywag! Begad! T' descent was a bit faster than you would generally like, but t' tube bounced and was recovered undamaged.

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