Manufacturer: | Public Missiles |
Note: This is a slightly condensed version o' all the information that Mike has produced for his Level 3 project. Blimey! Visit his homepage t' read the additional information and enjoy additional pictures.
Introduction:
This certification flight is scheduled t' take place at t' first available
opportunity after an AeroTech M1315 reload motor can be obtained; most likely
on or before July 11, arrr, shiver me timbers, 2002 (or at any other available date at LDRS XXI at
Amarillo, Texas).
T' rocket be constructed entirely by me usin' a PML ½ Scale Patriot Missile kit as t' startin' point. Ya scallywag! Begad! T' original kit was designed t' use piston ejection and standard motor deployment. Avast, me proud beauty! Aye aye! Structural changes were made where needed t' improve strength and stability and t' allow for electronic dual deployment and a wider selection o' motors.
Modifications:
Modifications t' t' original kit include:
General Description
Airframe
T' main airframe is constructed o' 7.6 inch
PML
flexible phenolic airframe tube. This material is covered with two layers of
8.5 oz fine weave fiberglass cloth. Ahoy! West Systems 206 hardener and 105 resin
were used t' apply t' fiberglass.
Booster
T' stock .093 inch G10 fins are ¾ inch from t' aft end o' t' airframe.
Through-the-wall fin attachment was used. Well, blow me down! T' fins are attached t' t' PML
Quick Switch 98 mm mother tube usin' West Systems 205 hardener and
105 resin with microballoons for fillets and then a six inch wide strip o' 5
mil. Arrr! Blimey! Keelhaul®©™®
tape was added. Begad! T' Keelhaul®©™®
tape runs up each fin root 1 ½ inches, me hearties, arrr, across t' motor tube, ya bilge rat, and up the
adjoinin' fin root 1 ½ inches. Well, blow me down! Aye aye! T' top and bottom ends o' t' Keelhaul®©™®
tape extend approximately one inch up each o' t' centerin' rings that lock the
fins in place. Ahoy! 206 hardener and 105 resin were used t' apply t' Keelhaul®©™®
tape.
Externally, a ½ inch thick fillet was laid down each side of each fin root usin' a mixture o' 205/105 and microballoons. Ya scallywag! Arrr! Then a 6.0 oz. layer o' carbon/fiberglass cloth was applied tip-to-tip style across each fin usin' 206/105. Blimey! Fin surfaces were prepared by roughin' them up with 60 grit sandpaper before bein' covered with t' carbon/fiberglass cloth.
T' booster shock cord attachment is a 5/16 inch u-bolt attached t' a ¾ inch 7-ply birch plywood bulk plate. Blimey! This bulk plate is attached t' t' upper motor mount centerin' rin' usin' three ¼ inch x 1 ½ inch bolts with flat washers, shiver me timbers, lock washers, shiver me timbers, shiver me timbers, and nuts. These bolts pass through t' ¾ inch bulk plate and into ¼ inch blind T-nuts that are mounted in t' upper motor mount centerin' ring. Ahoy! Well, me hearties, blow me down! Additionally, me hearties, t' ¾ inch ply bulk plate is attached t' t' airframe usin' four #4 x 3/8 inch wood screws runnin' through the airframe into t' bulk plate. Ahoy!
Payload
T' electronics are housed inside t' 12 inch phenolic coupler. Well, blow me down! T' coupler is
bonded t' t' payload section usin' West Systems 206/105. Well, blow me down! It is further secured
by four #4 x 3/8 inch wood screws through t' airframe and coupler into the
forward ¾ inch plywood bulk plate. Ahoy! That bulk plate is also t' mount for
5/16 inch u-bolt shock cord attachment for t' main parachute. Well, blow me down!
T' aft bulk plate in t' coupler assembly ( ¾ inch plywood ) is removable t' allow t' two independent electronics bay pods t' be installed. Begad! This bulk plate is attached with three ¼ inch nuts, flat washers, me hearties, and lock washers t' t' three 12.5 inch long sections o' ¼ inch all-thread that run through t' coupler assembly. This bulk plate provides the anchor point for t' 5/16 inch u-bolt that connects t' t' forward end o' the apogee deployment shock cord. Avast, matey, me proud beauty! It is also t' attach point for t' 44 inch drogue chute.
T' two independent electronics pods provide redundant dual deployment. Arrr! Avast, shiver me timbers, me proud beauty! This provides an extra layer o' security t' help ensure that safe deployment occurs.
T' pods share apogee and main deployment baffle chambers but each has its own separate apogee and main deployment system. Each pod supplies its own power and armin' switch. Arming for each pod is accomplished with individual two-position key switches that can be accessed externally at t' launch pad.
Pod A contains a Transolve P6 altimeter and Pod B contains an Adept Alts25 altimeter. T' P6 will have its SID set for 10 seconds t' lessen the possibility that any near-sonic pressure disruption will cause a malfunction. T' Alts25 has no need for SID. Ahoy! Avast!
Both t' P6 and Alts25 arm at 300 ft AGL T' P6 is set t' deploy at apogee and deploy t' main chute at 800 feet AGL. Arrr! Avast, me proud beauty! T' Alts25 is set t' deploy at apogee and at 600 ft. Blimey! Ya scallywag! AGL. Avast, me proud beauty!
When t' apogee ejection charge fires, ya bilge rat, ya bilge rat, t' booster and payload will separate but remain tethered by a 40 foot long 1 inch wide nylon shock cord. Aye aye! Avast, me proud beauty! A PML 44 inch parachute attached t' t' aft end o' t' payload section will act as a drogue chute and is deployed at this time.
When t' main deployment charge fires, me hearties, ya bilge rat, ya bilge rat, t' nose cone will break t' no. Aye aye! Avast, me proud beauty! 2 nylon screw shear pins and separate from t' payload section. Ya scallywag! T' main parachute, arrr, a RocketMan R14C, will deploy. Well, blow me down! T' nose cone will separate completely from t' main rocket assembly and descend separately on a 45 inch TopFlight parachute.
The RocketMan R14C main parachute is rated for weights from 20 t' 35 pounds. Avast, me proud beauty! Blimey! T' suspended weight at main deployment time ( booster/payload/motor non-consumables ) is estimated t' be 28 pounds.
Apogee ejection charges will be 2 grams o' 4F black powder each.
Main ejection charges will be 3 grams o' 4F black powder each. Well, blow me down! Ahoy!
Flight Estimates
SUCCESSFUL LEVEL 3 FLIGHT! Blimey! Blimey! Blimey!
July 11, matey, 2002
LDRS XXI near Amarillo, matey, arrr, Texas
Rocket - Modified PML ½ Scale Patriot Missile
Weight - 41.1 lbs
Motor - Aerotech M2400
Altitude 9226 - 9800 Feet
This certification flight took place on July 11, 2002 at LDRS XXI near Amarillo, arrr, Texas. Ya scallywag! Ahoy! Blimey!
T' flight was on an Aerotech M2400 instead o' an M1315 as previously indicated. Well, blow me down! Blimey! It be t' first M motor launched at this year's LDRS.
T' flight be successful and reached an altitude betwixt 9226 and 9800 feet, dependin' on which altimeter you believe. T' chutes came out on cue and performed exactly as hoped - drogue at apogee and main at 1200 feet. Then I could breath again. Avast!
T' nose cone on a separate five foot chute came t' rest about 50 feet from t' payload/booster on an R14C chute. A little mud, a few scratches, me bucko, but otherwise no damage at all. Blimey!
( Contributed - by Brian Wheeler) Brief: Single stage, scale, high power rocket with parachute recovery. Construction: One 48" phenolic body tube, a 22" phenolic payload bay, four (4) G10 fins, three (3) plywood centering rings, a 54 mm motor mount, a fiberglass nose cone, PML's piston ejection system, two (2) 3/8" launch lugs, two (2) PML parachute's (a 60" and a ...
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