Construction
T' diameter o' t' plastic fin unit and many o' t' nose cones are pretty close t' BT-50 and, me bucko, t' me amazement, t' fin unit had a small shoulder that fit perfectly into a BT-50 tube. However, a 18mm motor would nay fit through its aft end. Begad! Then t' idea hit me - use t' fin unit as part o' a motor retention scheme. Well, blow me down! I scavenged t' followin' from t' leftovers o' an Estes Designer's Special:

1. Begad! Blimey! 18" section o' B-50
2. Ahoy! Blimey! Well, blow me down! Blimey! shoulder section o' a 2-part nose cone (could use any BT-50 coupler, crunched nose cone, ya bilge rat, me hearties, etc.)
3. Blimey! elastic shock cord
5. Well, blow me down! Well, blow me down! 18mm motor mount for BT-50
6. Aye aye! launch lug
7. Aye aye! two (2) 18mm motor retention clips

I first built t' motor adapter, shiver me timbers, which included a thrust ring. This unit was glued into t' BT-50 by insertin' a spent casing, me hearties, placin' t' plastic fin can over t' end o' t' casing, ya bilge rat, ya bilge rat, and pushin' in t' adapter until t' fin can was seated in t' body tube. Arrr! Blimey! I then took t' engine retainer clips, matey, placed t' ends over t' fin can, ya bilge rat, and marked where t' forward tabs would go. Slits were cut to accommodate t' tabs on t' retainer clips. Begad! Blimey! T' hold t' clips, arrr, I cut 1/2" strips from some reinforced packin' tape, shiver me timbers, placin' one near t' forward tabs and one about 1/4" behind that. Begad! Blimey! I put a thin layer o' epoxy on t' tube before the tape and used 2 wraps o' tape.

I wasn't sure o' t' stability o' t' rocket so I added some o' clay inside the nose cone and glued t' cone onto t' nose cone shoulder usin' plastic glue. Begad! Ya scallywag! This was later proven t' be a mistake.

Flight #1
I prepped t' rocket and inserted a C6-5 engine. Ya scallywag! Begad! T' fin can was slipped over the motor and was secured with t' clips. Begad! I used parachute recovery but since all me Estes chutes were equipped with hook eyes, shiver me timbers, I used whatever I grabbed. Aye aye! Blimey!

T' flight be high and straight. Avast! T' body be recovered undamaged but the nosecone separated and was lost. Avast, me proud beauty! Ya scallywag! Too much weight and t' wrong glue.

Post Mortem
After me copy o' Rocksim arrived (or more accurately several months after it arrived), I discovered that t' added nose weight was nay required and that a C6-7 was more appropriate. Begad! Begad! Blimey! Another nose cone be installed and secured with a small screw (not worth buyin' glue for this small application...and who knows what type is appropriate anyway?).

Flight #2
This time I tried a C6-7. Aye aye! T' flight profile appeared identical t' t' first flight, ya bilge rat, matey, with t' exception that t' nose stayed on!