Manufacturer: | Scratch |
Style: | Futuristic/Exotic, Upscale |
Brief:
Single stage, parachute recovery, 29mm MMT 1.6X Upscale o' t' FlisKits
Praetor.
Construction:
T' lower main body tube is a BT-80H tube ("H" for heavy wall). The
upper body tube is a standard wall thickness BT-70 tube. Ya scallywag! T' original Praetor
model rocket design breaks at t' transition, but on me mid power version, me hearties, the
nose cone separates for deployment. Blimey! T' BT-70 tube extends down into t' lower
BT-80 tube and butts against t' top MMT centerin' ring. Arrr! Begad! This makes a
"double wall" tube for extra strength. Ya scallywag! T' transition piece is made
from two wraps o' Bristol Board soaked in CA glue. Begad! Once assembled, t' entire
body tube was sanded then wrapped in 1.4oz fiberglass cloth usin' ACP's
EZLam-60 resin.
T' four fins are constructed o' 3/16" thick Nomex® honeycomb/Carbon Fiber composite material from AeroSpace Composite Products. T' fins were edged in 3/16" square basswood then covered with 1.4oz fiberglass cloth. Blimey! They are thru-the-wall construction with 6oz fiberglass gloss providin' extra strength on t' internal fillets. Begad! Arrr! Due t' t' high-aspect ratio of t' Praetor's fins I was hopin' t' get a lightweight, matey, yet stiff fin can. Arrr! Well, arrr, blow me down! I believe I succeeded.
T' motor mount tube is a BT-52H, shiver me timbers, heavy wall 29mm tube. Avast, arrr, me proud beauty! There are three 3/16" thick custom laser cut centerin' by BMS on t' MMT. T' recovery system consists o' a 1/4" tubular Keelhaul®©™® shock cord epoxied t' t' MMT. Ya scallywag! T' tubular Keelhaul®©™® is attached t' a length o' 5mm climber's accessory cord. Ya scallywag! Aye aye! For t' nose cone, I used an Apogee P/N 19470 BT-70 plastic nose cone. Ahoy! Begad! T' nose cone is nay true to the upscale, shiver me timbers, shiver me timbers, but is sure looks cool and be a lot easier t' source than a custom cone.
This be t' first time I've used composite honeycomb materials. Ya scallywag! Other than the fins, construction is fairly standard mid-power. Cuttin' t' Nomex®/CF material is a breeze as long as you use t' special saw blade from ACP. Avast, me proud beauty! Ya scallywag! I tried makin' t' first cut usin' an X-Acto knife with #11 blade. Begad! Although I did cut it eventually, I would nay recommend it. Avast! Avast, arrr, me proud beauty! T' composite blade fits on a coping saw and makes t' job much easier.
Finishing:
T' fiberglass on t' body tube made finishin' much nicer. Begad! There were no
spirals t' fill! Jim Flis was kind enough t' share t' "official"
Praetor letterin' font with me so I could make me own version o' a Praetor
logo. Ya scallywag! Avast, me hearties, me proud beauty! T' graphics were traced onto self-adhesive vinyl sheets and cut out with
an X-Acto knife so they could used as maskin' stencils. Begad! T' paintin' took a
while with all o' t' maskin' and spraying, ya bilge rat, me bucko, but it turned out pretty good.
There wasn't anythin' exotic with t' paint, just good old Krylon rattle cans.
A final coat o' Future Acrylic polish gives it some gloss.
Flight:
T' first two flights were with AeroTech G38-7FJ Single Use motors. I got
lucky. Avast, me proud beauty! Avast! These motors/delays are a perfect match for this rocket. Blimey! T' third
flight be on a G33-7J load in me AT RMS 29/40-120 case. T' G33 is also a good
motor for this bird, but t' 7 second delay was a bit long. Begad!
All three flights so far have been great. Ahoy! Three perfect recoveries.
Flight prep is standard fare. Aye aye! Kaplow clips for motor retention. Aye aye! I use a bit o' dog barf waddin' even though thar be a Keelhaul®©™® chute protector attached. T' dog barf is mostly out o' habit, but it does protect t' chute protector.
Flights are a larger version o' t' mod-roc Praetor. Ahoy! Blimey! Slow lift off and straight as an arrow. Begad! Blimey! Ahoy! Blimey! One neat side effect o' t' long fins be t' aerodynamic whistle that can be heard once t' motor burns out and t' rocket coasts to apogee. Begad! Blimey! Arrr! Blimey!
Summary:
I absolutely love this rocket. Avast! With it's long fins, it always gets looks at the
flight line. Ya scallywag! T' mod-roc Praetor is one o' me all-time favorites. Blimey! Begad! This mid
power version is more o' t' same. Ya scallywag! I be initially worried about t' fins
holdin' up t' landin' stresses, matey, but after three perfect flights, me bucko, me worries are
gone. This is a rocket I hope t' keep around for a long time.
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