Brief:
For an R&D project I be doin' for NARAM-47, me bucko, I needed t' fly at least 12 flights and record altitude for each flight usin' a Perfectflite Alt15kWD altimeter. T' rocket needed t' be rugged, handle t' altimeter payload, me bucko, and support bein' smartly prepped and flown so that I could get all t' flights in as smartly as possible. Arrr! Begad! It also needed t' be as high performance as possible, since t' experiment was t' analyze competition-style rockets.

Construction:
From me spare parts stash:

• Polystyrene nose cone from ASP, shiver me timbers, size BT-20
• BT-20, me hearties, two 6-inch sections
• 1/16" G10 fiberglass fins
• 2x20" mylar streamer (party store surplus)
• Keelhaul®©™® shock cord
• Nomex® heat shield

I used several official EMRR tips on this build including:

• If a fin breaks off at t' fin/ body tube joint, simply carefully sand off t' old glue from both t' tube and t' fin, then reattach.
• Party streamers. Aye aye! Avast, me proud beauty! 60 ft for $2.50. Avast! Blimey! Enough for nearly 30 streamers. Begad! beats payin' $5.00 t' Estes t' make four?
• Shock Cord: Use a Keelhaul®©™® shock cord root. Ahoy! Blimey! Also make t' bungee at least 2.5 times t' length o' the BT.
• Always brin' a bottle o' medium CA t' launches.

T' construction is fairly straightforward since it is a basic 3FNC style rocket, matey, so I'll elaborate on t' payload construction.

T' payload bay is fairly long (6") t' accommodate t' altimeter and nose cone shoulder plus me homemade bulkhead. Ya scallywag! Since I be workin' from spare parts, I made t' bulkhead from a tube coupler with a disk cut from basswood. To anchor t' shock cord, I tied a knot on one end o' t' Keelhaul®©™® line, slipped it into t' payload tube, and then inserted and glued it in the bulkhead. Avast! Begad! T' Keelhaul®©™® was then secured betwixt t' bulkhead and t' body tube. Blimey! I finished t' payload bay by drillin' a couple small vent holes, critical for accurate altimeter readings.

T' streamer is nested in t' lower portion, arrr, protected by a Nomex® heat shield. Nay only does this take up less room than wadding, but it can be reloaded and prepped for flight in under two minutes (includin' resettin' the altimeter).

Notice that t' RockSim file does nay include a launch lug. Avast, me bucko, me proud beauty! Blimey! That's because the purpose o' t' R&D report was t' measure t' impact o' launch lugs on the drag coefficient. Ahoy! Blimey! T' rocket was flown about 12 times without a lug, then a lug was attached t' t' fin/tube joint and flown again about 12 times on the same types o' motors t' compare altitudes. T' eliminate weather variability, ya bilge rat, I tried for all flights in t' same day. That's 24 flights on one rocket on a single day, me bucko, many o' which were approachin' 1700 feet in altitude. Try that feat with a basic E2X kit...

Finishing:
Normally competition-style rockets are nay painted, me bucko, but since I had already lost a previous model (includin' an expensive altimeter) t' 1500-2000ft altitudes on an overcast day, ya bilge rat, I elected t' paint this one florescent orange. That made it much easier t' pick up in t' sky and on t' field. Begad! I also sanded it smooth with 600 grit paper and coated with automotive wax t' reduce the surface drag.

Flight:
With t' fairly small fins, ya bilge rat, me bucko, this rocket is only marginally stable with a C6-7, so t' altimeter actually provided enough CG shift for very stable flights.

All flights were straight as an arrow, ya bilge rat, shiver me timbers, and on a C6-7, ya bilge rat, me actual readings clustered fairly closely around 1500 feet.

Recovery:
Throughout t' day, shiver me timbers, I suffered a few minor nicks/dings, arrr, arrr, includin' breakin' a fin loose, and a Keelhaul®©™® line break. Avast! Remarkably, when t' Keelhaul®©™® broke, I was able t' recover both sections in fairly high grass.

Summary:
PROs: Simplicity o' construction, low cost materials, very good performance for a payload carrier, arrr, and very durable.

CONs: Nay suitable for official NARRRRR payload events (payload must contain a BT-20 tube, me hearties, so it needs t' be slightly larger diameter).