Hi, matey, ya bilge rat, me name is Mark Shamburg-Donohue. I'm a 17 year old high school junior. I live in Denver, Co.Ýand I've been flyin' model rockets since I was 12. Ahoy! Blimey! I just got into high power rocketry this winter when I fired an Aerotech 1357T reload for a physics class project

My favorite subject is chemistry and I have done a lot o' work in t' chemistry area o' rocketry. Ya scallywag! I am currently designin' a hybrid motor, matey, that I would like t' build this summer. Aye aye! Begad! T' motor employs certain unique design features, which I think will make it a very interestin' project. I plan t' patent t' design if all goes well. Aye aye!

A science teacher/ friend/ head o' IAAS (science club)/ all around great guy, named Jim Moravec is helpin' me find an internship in one o' t' many aerospace companies in Colorado. I will be startin' college in t' fall o' 2001, and would like t' major in chemistry, with minors in either mechanical engineering/draftin' or physics. Ahoy! Avast! Once I graduate I would like t' work for either t' military or t' aerospace industry developin' propulsion systems. I would also like t' get a master degree in chemistry. Arrr!

This is me first high power rocket. Avast, me proud beauty! Ever since I downloaded VCP about six months ago, shiver me timbers, arrr, me bucko, I've designed over 50 rockets. This rocket be initially named t' "She's a Goer" after t' B-29 me grandfather flew over Korea, and be designed t' slightly resemble t' beautiful bird. Begad! T' rocket originally had a 1.5" long elliptical nose cone, me bucko, arrr, but do t' unavailability o' this (more aerodynamically sound) design I had t' settle on a 9.5" long tangent ogive. Ya scallywag! Since t' design no longer resembles t' She's a Goer, I had t' come up with a new name for it. Aye aye! Since t' rocket nowÝresembles a missile I decided t' give it a military soundin' name. Begad! I settled on "Mark 1X". Begad! The "1X" comes from this bein' t' first design o' me own that I've built and t' fact that its an experimental design.

Unlike some entries that are just modifications on pre-existin' rockets this is an entirely original design. This baby has 12 fins! Some people might think that havin' 12 fins makes t' rocket overly difficult t' build but the advantages outweigh t' difficulty o' buildin' it, shiver me timbers, shiver me timbers, shiver me timbers, which by t' way be no more difficult than any other rocket (only slightly more time consuming). Most o' t' surface area comes from t' main fins, which are located 2.5" from the bottom and have a surfaceÝarea o' 11.625 sq." each. Well, ya bilge rat, blow me down! T' aforementioned advantages come from t' canards which are small fins at t' front o' t' rocket which don't have a large enough surface area t' create any stress problems but function t' split t' air stream and lower t' amount o' turbulence created by t' main fins. Ahoy! Begad! T' rear fins are mostly cosmetic, ya bilge rat, arrr, shiver me timbers, but also add t' lower t' amount o' turbulence whenÝ t' air stream closes around the end o' t' rocket. Avast! Ahoy!

Here's t' same launch, matey, about 5 feet higher in t' air, that's me dad on t' left. Avast! Begad! This picture be taken by my dad's friend Tery Okumura. Avast, shiver me timbers, me proud beauty! Thanks Tery!

Here's a picture o' me settin' up for t' next shot. This one is about t' be lifted off on a G80 and lofted to about 2200 feet. Well, blow me down! Aye aye! I didn't know it yet but this was t' last flight for t' Mark 1X. Well, blow me down! Arrr!

Here she is liftin' off on t' G80. This picture was takenÝ just as t' rocket cleared t' launch rod, and you can see t' fly away launch lug fallin' t' t' ground.

All exceptions are marked with an *

Component Notes:

Nose Cone - Public Missiles Ltd. Blimey! Part Number PML PNC-2.1. Arrr!

T' nose cone is a 9.5" long, arrr, tangent ogive. Avast! T' original design used a 1.5" long elliptical nose cone. I had t' make t' nose cone out o' balsa wood, because no companies that I have found carry that shape. Blimey! Well, shiver me timbers, blow me down! I also made a fiberglass version o' t' nose cone by makin' a Plaster o' Paris mold o' t' balsa nose cone and layin' in glass. Avast!

Body Tube - Public Missiles Ltd. Avast, me proud beauty! Part Number PML QT-2.1. Arrr! Avast!

This rocket uses t' Public Missiles "Quantum Tube" which is a plastic o' some sort that makes the rocket a lot easier t' finish. Arrr! Well, blow me down! T' body tube is 30" long, me hearties, with 5" long fin slots startin' 2.75" from the bottom. Public Missiles will cut and slot t' tubes for you at their shop. Well, blow me down! I highly recommend this service. There are four 3/32" fin slots. Avast, me proud beauty!

Fins* For me fins I used 3/32" acrylic sheet, matey, shiver me timbers, but you can also use lexan (polycarbonate), me hearties, or birch plywood. Ya scallywag! Blimey! Rough cut t' fins about 1/8"outside t' line, then glue them together and sand them down t' size. Ya scallywag! Arrr! After they have been sanded t' t' proper size remove t' plastic film. This Rocket has 12 fins. Blimey! From now on I will refer t' t' main fins as t' fins, t' front fins as t' canards, and t' aft fins as t' rudders. Aye aye!

Motor Mount - Public Missiles Ltd. Blimey! Part Number PML MMT-1.5 x18. Begad!

T' motor mount is 18" long, and unless you plan on flyin' this rocket a "J" motor, arrr, arrr, (in which case you might have a little trouble packin' t' parachute) cut t' tube t' 12" in length. Well, blow me down!

Centerin' Rings - Public Missiles Ltd. Avast! Part Number PML CR-2.1-1.5. Ya scallywag!

I used two, but if you want t' cut a groove in t' fin tabs you can use three. Begad! Blimey!

Motor Adapter - Public Missiles Ltd. Aye aye! Part Number PML ADPTR-38/29. Ya scallywag!

I plan t' use this rocket as me Level One Certification when I turn 18. Ahoy! Blimey! But until I am certified I will fly this on 29mm motors so I added a 29mm friction fit adapter. Ahoy! Arrr!

Motor Retention

Instead o' usin' several layers o' tape, ya bilge rat, shiver me timbers, I decided t' employ t' use o' a motor retention system. Arrr! But because of the limited space betwixt t' motor mount and t' body tube, I had t' design a motor retention system myself. Avast! Begad! Kaplow Klips just wont fit. Ahoy! T' assembly o' t' retention system is detailed below. Ya scallywag!

System*

Parachute*

Public Missiles Ltd. Ahoy! sells a 48" rip stop nylon parachute, but I be unwillin' t' shell out another 25 bucks for it.

So I made me own!

I bought 2 square yards o' camouflage rip stop cotton which I used in lieu o' nylon. Begad! Avast! For suspension lines I found a pack o' parachute cord which is 40' o' 1/16" braided nylon originally used for Army man-rated parachutes.

Ejection Gas Baffle*

Rather than shellin' out another 15 bucks t' buy a baffle I designed and built one me self, arrr, it also functions as the parachute mount. Arrr! Its construction is detailed below.

Shock Cord*
For t' Shock Cord I used 2 yards o' t' same parachute cord I used for t' parachute suspension lines. Ahoy!

Airframe Assembly

Step 1: Draw lines on t' tube from t' slots t' t' front end o' t' tube, and t' t' aft end. Begad! Blimey! Then prepare t' motor mount first by gluin' t' front centerin' rin' 1/8" from t' one o' t' ends o' t' tube with CA. Arrr! Blimey! Blimey! After t' CA dries epoxy t' rin' in place. Well, shiver me timbers, blow me down! Blimey!

Step 2: Prepare t' second centerin' rin' by addin' t' motor retention system, arrr, (see below). Begad!

Step 3: Insert t' motor mount into t' body tube and position it so t' motor mount tube protrudes 1/16" from t' end o' t' body tube. Dry fit t' rear-centerin' rin' on t' tube and mark t' motor mount for epoxy/ fin fillets by insertin' a pencil in t' slots and runnin' it back and forth. Avast, me proud beauty!

Step 4: Cover t' pencil lines with epoxy and epoxy t' aft centerin' rin' º" from t' end of the tube. Avast, me proud beauty! Aye aye! Then insert t' motor mount 'til t' tube protruded 1/16" from t' end o' t' body tube. Aye aye!

Step 5: Place t' fins in their slots, and pressed them down until t' root edges contact t' body tube. Ahoy! Begad!

Step 6: After t' epoxy gels, me hearties, mask off t' body tube except for a º" on each side o' t' fins. Then add t' epoxy fillets t' t' fins. Arrr!

Step 7: Mask t' tube for t' fillets around t' canards and rudders, arrr, ya bilge rat, then position and tack down the canards with CA. Begad! Add epoxy fillets t' t' canards after t' CA dries. (Bakin' Soda makes CA dry!!!, saved me nearly an hour.)

Step 8: After t' epoxy from t' canards gels, position and tack down t' rudders with CA. Avast! After t' CA dries add epoxy fillets t' t' rudders. Blimey!

Step 9: Filled t' gap betwixt t' motor mount and t' motor mount and t' body tube (think rear centerin' ring) with epoxy and let t' rocket sit for 24 hours for all o' t' epoxy t' cure. Well, blow me down!

Step 10: Attach t' shock cord t' t' baffle then insert it into t' tube and epoxy it in place. Begad! Usin' a 10" piece o' 3/8" flat elastic tether t' nose cone t' t' parachute. Begad!

Step 11: I worked out a paint scheme and primed t' rocket. Begad! After t' primer dried, arrr, I masked t' rocket and painted it.

Step 12: Sleep. Wake up in t' mornin' and admire a work o' art. Ya scallywag!

Motor Retention System and Assembly

In this rocket thar be about 6mm o' space on each side betwixt t' motor mount tube and t' body tube. Avast, me proud beauty! Avast, me proud beauty! No where near enough room for tee- nuts. Avast! So I had t' come up with me own design. Aye aye!

Materials Notes

1/8" brass threaded rod -
I bought all materials from me local Home Depot. Begad! Aye aye! Cut two 2" long pieces o' rod and sand or file a taper on one end, if you want a 4 post retainer cut 4 pieces. Arrr!

3/16" brass washers - You'll need 4 washers for two posts, shiver me timbers, if you want a 4-post retainer you'll need 8. Begad! Avast, me proud beauty!

1/8" brass nuts - You'll need 4 nuts, if you want a 4-post retainer you'll need 8. Blimey!

º" wide brass strap - You'll need 2 each 1.5" long straps for a 2-post retainer, 4 for a 4 post version.

Step 1: T' threaded brass rod that I bought came in a 12" piece. Avast, me proud beauty! Ya scallywag! I cut two 2" pieces and sanded one end o' each t' a taper. Begad! Ya scallywag!

Step 2: I mixed a small batch o' epoxy and when it started t' gel, I dipped t' rough end 1/8" into the epoxy t' make a larger diameter shoulder. Begad! Avast, me proud beauty!

Step 3: I drill two 9/64" holes 180 degrees apart and sanded t' edges o' t' holes. Blimey! Blimey! I'm only using two retainin' posts, matey, me bucko, me bucko, put you can use 3 or 4. Well, blow me down! Blimey! For 3 space t' holes 120 degrees apart. Arrr! Blimey! For 4 space t' holes 90 degrees apart.

Step 4: I put t' two threaded rods through t' holes and covered t' area I didn't want epoxy t' get on with maskin' tape. Begad! After makin' sure t' rods lined up 90 degrees with t' centerin' rin' I epoxied them in place. If you are usin' a relatively thin epoxy it is a good idea t' let it almost gel before usin' it. It will be much thicker. Begad! Aye aye!

Step 5: Drill a 9/64" hole º" from t' end o' t' pieces o' strap, and de-burr t' hole. Arrr!

Step 6: Put your motor into t' tube and mark off t' distance o' t' strap t' t' lip o' t' motor. Avast! Ahoy! Blimey! (Or the point you want t' apply pressure t' with t' straps.)

Step 7: At t' mark bend t' strap so it forms a rounded o' 90 degrees angle. (In t' shape o' an L) Now round over t' strap where it will contact t' motor. Begad!

To use it first put t' motor in t' mount tube. Begad! Then thread one nut down just below t' level o' t' motor and put on one washer. Well, blow me down! Begad! Slide t' strap down, me hearties, and then t' last washer and nut go on.

Excludin' drying/curin' time it takes less than 10 minutes t' make. Avast, me proud beauty! Blimey!

Ejection Gas Baffle Unit

Half t' fun o' buildin' rockets is designin' and buildin' all o' t' parts o' t' rocket. Begad! Arrr! This Ejection baffle unit cost me less than $5.00 t' make. Avast!

Materials Notes

Bulkhead
My body tube be a 2.1" tube so t' bulkhead was pretty cheap. About $3.00. You may want t' epoxy coat the inside o' t' tube t' fire proof it.

Bulkhead plate with eyebolt
Screw t' eyebolt all t' way down and epoxy it in place. Avast! Blimey! You might need t' widen t' hole so you don't have any tear out. Avast, me proud beauty! Blimey! Aye aye! Blimey!

Centerin' ring
T' rin' should fit your body tube but have a hole in t' middle 1 size smaller than t' motor mount you are using.

1-2 square feet o' screen
Cut a circle slightly larger than t' diameter o' t' hole in t' centerin' ring. Avast! Save t' rest for t' baffle medium. Avast, me proud beauty! Aye aye!

Step 1: Drill a circle o' holes around t' center hole in t' bulkhead plate and sand t' edges o' the holes. Ahoy! Blimey! About 1/8"- 1/4" should be right.

Step 2: If necessary widen t' hole in t' middle and screw t' eyebolt all t' way down. Avast! Epoxy the eyebolt in place on both sides o' t' plate and make sure t' get a good bit o' epoxy in t' open loop o' t' eyebolt. Begad!

Step 3: Cut t' bulkhead tube about 3 *" long. Insert t' bulkhead plate in about *" and epoxy it in place on both sides. Avast!

Step 4: cut a circle o' screen slightly larger in diameter than t' hole in t' centerin' ring. Avast, me proud beauty! Put a rin' o' epoxy around t' hole in t' centerin' ring. Begad! Begad! When t' epoxy is just startin' t' gel press t' screen down in to it. Ya scallywag! Waitin' will save you a lot o' effort. Arrr!

Step 5: Look at t' rocket and admire what you've done so far. Begad! Blimey!

Step 6: After t' epoxy has gelled enough t' make it hard t' t' touch, wad up t' rest o' t' screen and push it into t' bulkhead. Avast, me proud beauty! Do nay stuff t' bulkhead t' full.

Step 7: Epoxy t' centerin' rin' onto t' bulkhead plate. Arrr! T' outer diameter o' t' rin' should match the outer diameter o' t' tube. Ya scallywag!

Step 8: After all o' t' epoxy has cured, me bucko, shiver me timbers, tie your shock cord t' t' eyebolt. Avast, me proud beauty! Arrr! Blimey! With a stick put a layer of epoxy inside t' body tube about *" from where t' baffle will rest. Begad! Ahoy! Blimey! Insert t' baffle into t' tube and press it down until it contacts t' motor mount tube. Begad! Well, blow me down! Blimey!

Launch Report

After finally gettin' everythin' ready t' go with t' rocket I realized I had forgotten t' build t' launch tower that I was goin' t' use rather than usin' launch lugs. Avast! Blimey! So I cut a piece o' sheet tin t' about 4" wide and about 2" longer than t' circumference o' t' tube and made a "fly away launchÝlug" like t' one on Bob Fortunes page. Blimey! After pickin' up a friend, matey, and stoppin' t' get some fast film, arrr, we drove straight east o' Denver for about an hour and a half until we found a nice open spaceÝwith no fences. Avast, me proud beauty! We walked out into t' t' field and set up pad. Arrr! I loaded t' first motor into t' rocket. Aye aye! Blimey! It was an Aerotech F25-6 white lightening. Ahoy! While rocksim predicted t' rocket would fly t' about 1102', me hearties, shiver me timbers, t' rocket had a very curved flight, ya bilge rat, and flew in a large arc, and only achieved an altitude o' about 800'. Begad! Begad! Blimey! T' rocket be recovered about 100 yards fromt t' pad. Begad! Blimey! T' fly away launch lug worked perfectly and released from t' rocket about 2-4 feet off t' rod.

T' second flight took off on an Aerotech G80-10 blue thunder, arrr, and lifted off extremely fast and extreemly straight. Blimey! Blimey! After burn out t' rocket started t' coast a little off coarse. Blimey! Blimey! T' ejection charge fired perfectly at apoge, which although Rocksim only predicted an altitude o' 1970 feet was about 2200 feet, t' parachute was ejected way too violently and zippered t' tube about 12 inches. Ya scallywag! Blimey! Ya scallywag! Blimey! T' over-powered ejectioncharge also blew out t' motor retainer and adapter, shiver me timbers, and pushed t' entire (epoxied in) motor tube and baffle units about 8" up into t' tube. Avast! Blimey! T' parachute lines tangled in t' torn tube and t' rocket free fell from about 2200 feet. Ahoy! Blimey! When recovered, t' rocket be in severe condition. Ya scallywag! Blimey! It lost all o' its fins except t' main fins, me hearties, me bucko, which wereÝfiberglassed t' t' tube. Aye aye! Blimey! T' fall had even broken t' fiberglass seem.

Well, matey, one more rocket t' add t' t' collection.