Documentation
for
PATRIOT IV
9/15/05
By David R. Moore TRA # 1445 NAR # 80269
Section
1: TAP Preflight Data Capture
Section 2: Patriot
IV Construction Article
Photographs
Diagrams
Simulation Results
Section 3: Sample
Checklists
Level 3 Data Capture Form
CAPTURE
NAME: David
R. Moore ADDRESS: PHONE#
TRA# 1445 LAUNCH LOCATION: DATE:
ROCKET SOURCE:
KIT
SCRATCH x
ROCKET DIAMETER: 6 ROCKET LENGTH: 120
ROCKET WEIGHT LOADED: 44 LBS MOTOR TYPE: Aerotech
M1315, Dr.
Rocket case.
THRUST TO WEIGHT RATIO: 11:1
AVIONICS DESCRIPTION: Two AltAcc,
One miniAlt/WD rigged for
dual deployment.
LAUNCHER REQUIREMENTS: Unistrut rail LENGTH: 10 feet minimum
CENTER OF GRAVITY: 22 >CP HOW CALCULATED: Balanced
MAXIMUM VELOCITY: 721 fps HOW CALCULATED: Winroc
MAXIMUM ALTITUDE: 7566 feet HOW CALCULATED: Winroc
PROJECT DISCRIPTION
Patriot IV is an unguided, single staged sounding rocket
intended for subsonic flights. The design is based on my highly successful
series of Patriot rockets, scaled up from my level-2 certification, 4 rocket.
A total of 4 rockets have been built with the same type on construction. Using
38 and 54mm engine mounts.
SPECIFICATIONS 
7/15/05
Length: 120
Diameter: 6.125
Fin span: 24
Empty weight: 38 pounds
Prepped weight: 42 pounds
Liftoff weight: 44 pounds
Motor: Aerotech RMS M1315
MATERIALS
Nose cone PML 24 fiberglass
Airframe
Motor tube Hawk Mountain G12 fiberglass,
Coupler tubes Hawk
Mountain G12 fiberglass
Fins G11,
3/16 thickness
Bulkheads G10-FR4, 3/16 with Ύ 12-ply birch, lathe turned
Centering rings G10-FR4,
3/16 with Ύ 12-ply birch, lathe turned
Adhesive Devcon 5, 30 and 45 minute epoxy.
Recovery attachment 5/16
forged steel eyebolts
5/16
steel triangular quick links
Parachute harness 1x1/8
nylon synthetic webbing with bolted loops
Parachutes Two Rocketman R12C
CONSTRUCTION DETAILS
Fin Root:
Fins are mounted through the wall to the motor tube. The
G11 fins and all G10 tubing, bulkheads, and centering rings are sand blasted,
at the epoxy areas for a better epoxy adhesion. Weaved fiberglass is epoxy over
the motor tube, up on the fin root approximately 1 for additional strength.
The centering ring has a epoxy-in threaded insert to provide a hard point to
attach the lower rail guild.
ADITIONAL CONSTRUCTION DETAILS
Bulkheads & centering
rings:
Construction is 3/16 G10 and
Ύ 12-ply birch, epoxy together. One recovery eye bolt is mounted to the centering
ring. The center eye bolt is threaded into the motor case. Note the sand
blasted areas.
RECOVERY SYSTEM
The duel-deployment method is employed. The vehicle is
composed of 2 major sections: the fin can and airframe. An electronics bay is
situated in the center on the main airframe. Composed of a coupled tube with
ends sealed by bulkheads, this single unit contains all on-board electronics
and injection charges. Upon reaching apogee, the drogue charges will be fired,
blowing the nose cone off of the air frame and deploying one RC12 parachute.
After drifting to within 600 feet AGL, the main charges will be fired, ejecting
the payload section from the fin can and deploying the 2nd RC12
parachute for final descent.
The main electronics control for recovery is two Black
Sky AltAccs. A 3rd backup is a PerfectFlite MiniAlt/WD.
The four ejection charges are each composed of 10 grains
of 4FG black powder. They are contained in a ½ copper pipe cap, bolted to the bulkhead,
and sealed with masking tape. Activation is by Davyfire electric match.
Recovery attachment is by
5/16 forged steel eyebolts. These eyebolts have a solid ring. They are secured
by an aircraft lock nut backed up by a flat washers. The eyebolts have a solid
connection through the center of the electronics bay. The eyebolt on the front
of the fin can is bolted to the centering ring.
Electronics
The electronics bay is constructed of a full-length G10
coupler tube with G10 laminated to birch bulkheads. An insert ring of a G10
coupler tube is epoxy in place for the bulkheads to bear against. A single
piece of 5/16 all-thread connects the two eyebolts and hold the upper and
lower bulkheads against the inserted G10 ring. The electronics are surface
mounted on the G10. Arming circuits consist of a HD 10 amp toggle switch
actuated by a 1/16 rod pushed into a labeled hole on the side of the rocket. A
backup multi pole, single throw rotary switch is installed in a parallel
circuit for a backup in case of a sudden shock in one direction.
Motor retainer:
The aft centering ring has threaded inserts epoxy in
place to mount the Aero Pack, 75mm retainer.
PEFLIGHT CALCULATIONS
CP-CG RELATIONSHIP: After construction was completed, the rocket was
fully assembled with all hardware and recovery systems put into place. A dummy
motor was built using lead weights wrapped in cardboard. This placed the exact
weight of the loaded motor at the correct distance inside the motor tube. The rocket
was then balanced in its assembly cradle an the CG point noted at 80 from the
nose. The CPCAL program from Winroc was used to determined the CP position at 110.55
from the nose. Thus the CG lies 30.5 ahead of the CP. The CP is marked on the
airframe by a custom decal.
Flight Simulation: The Alticalc program from Winroc package was used to
predict the flight performance.
Checklist for
___________________________ Flight
date:______________ Page 1
ASSEMBLY AREA
_ Inspect airframe integrity
_ Inspect harness for damage
_ Inspect parachutes for
damage
_ Motor assembled per
instructions
_ Igniter assembled per
instructions
_ Electronics installed with
fresh batteries
Ejection charges installed
_Drogue _Main _Backup
Ejection charges connected to
electronics
_Drogue _Main _Backup
Ejection charges in safe
condition
_Drogue _Main _Backup
Harness attached to airframe
_Drogue _Main
Parachute attached to harness
_Drogue _Main
Ejection shields in place
_Drogue _Main
Parachutes packed and loaded
properly
_Drogue _Main
Shear pins installed
_Drogue _Main
_ Airframe screws tight
_ Motor installed
_ Motor retainer installed
_ Final check: assembly
completed
_ Balance check: CG ahead of
CP by 1 caliber
Checklist for
___________________________ Flight
date:______________ Page 1
LAUNCH AREA
_ Notify RSO, rocket is
moving to pad
_ Inspect pad and launch rail
integrity
_ Mount rocket on rail
check for unobstructed movement
_ Tail support at least 6
above blast deflector
_ Set launch rail angle to 80
+- away from flight line
_ Hold for photographs
_ Ask unneeded personnel to
clear area
_ Attach igniter to leads and
test continuity
_ Prepare payload for flight
_ Activate on board
electronics
_ Ejection charges armed
_ Insert igniter & check
continuity
_ Final check: ready to fire
_ Notify LCO rocket is ready
to fire
_ Move to safe zone and
observe flight
LAUNCH AREA
Observe rocket before
approaching:
_ Motor has completely burned out?
_ Motor was retained?
_ All ejection charges expended?
Parachutes deployed correctly?
_ Drogue _
_ Deactivate on board
electronics
_ Gather parachutes and bag
for inspection
_ Gather harnesses and place
inside tube
_ Police Landing area for
trash and/or broken parts
PERSONAL NOTES
I have been in the rocketry
hobby since 1968. High power rocketry since 1992. The Patriot
V is the 4th rocket built in a series of scratch built and test
flights to get to where I am now. Future planned construction will use a 98mm
motor, possibly with digital camera payloads.
11/6/2005
By David R. Moore TRA #1445 NAR # 80269
www.drmoore.org