Hi, arrr, me name is Mark Shamburg-Donohue. Avast, me proud beauty! I'm a 17 year old high school junior. Aye aye! Avast, me proud beauty! I live in Denver, Co.Ýand I've been flyin' model rockets since I was 12. Avast, me proud beauty! Begad! 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. Well, blow me down! Blimey! I am currently designin' a hybrid motor, that I would like t' build this summer. T' motor employs certain unique design features, which I think will make it a very interestin' project. Blimey! Blimey! I plan t' patent t' design if all goes well. Well, blow me down! Blimey! Avast! Blimey!

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. Arrr! I will be startin' college in t' fall o' 2001, shiver me timbers, and would like t' major in chemistry, with minors in either mechanical engineering/draftin' or physics. Arrr! 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. Avast!

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

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, ya bilge rat, 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. Arrr! Avast! 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. Blimey! T' rear fins are mostly cosmetic, shiver me timbers, but also add t' lower t' amount o' turbulence whenÝ t' air stream closes around the end o' t' rocket.

Here's t' same launch, me hearties, matey, arrr, about 5 feet higher in t' air, arrr, ya bilge rat, that's me dad on t' left. Arrr! Avast, me proud beauty! This picture be taken by my dad's friend Tery Okumura. Thanks Tery!

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

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. Part Number PML PNC-2.1. Well, blow me down!

T' nose cone is a 9.5" long, me bucko, tangent ogive. Ahoy! 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. Ahoy! 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. Ahoy!

Body Tube - Public Missiles Ltd. Ahoy! Blimey! Arrr! Blimey! Blimey! Blimey! Part Number PML QT-2.1.

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

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

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

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

Centerin' Rings - Public Missiles Ltd. Part Number PML CR-2.1-1.5. Well, blow me down! Blimey!

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

Motor Adapter - Public Missiles Ltd. Part Number PML ADPTR-38/29.

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

Motor Retention

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

System*

Parachute*

Public Missiles Ltd. Arrr! Ya scallywag! sells a 48" rip stop nylon parachute, but I was unwillin' t' shell out another 25 bucks for it. Begad! Ya scallywag!

So I made me own!

I bought 2 square yards o' camouflage rip stop cotton which I used in lieu o' nylon. Begad! Blimey! 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. Avast, me proud beauty! Blimey!

Ejection Gas Baffle*

Rather than shellin' out another 15 bucks t' buy a baffle I designed and built one me self, it also functions as the parachute mount. Begad! 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. Aye aye!

Airframe Assembly

Step 1: Draw lines on t' tube from t' slots t' t' front end o' t' tube, me hearties, and t' t' aft end. 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. Avast! After t' CA dries epoxy t' rin' in place. Begad!

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

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

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

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

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

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

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

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

Step 12: Sleep. Avast, me proud beauty! Wake up in t' mornin' and admire a work o' art.

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! No where near enough room for tee- nuts. Avast! So I had t' come up with me own design.

Materials Notes

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

3/16" brass washers - You'll need 4 washers for two posts, if you want a 4-post retainer you'll need 8. Well, arrr, blow me down!

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

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

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

Step 2: I mixed a small batch o' epoxy and when it started t' gel, shiver me timbers, I dipped t' rough end 1/8" into the epoxy t' make a larger diameter shoulder. Well, blow me down!

Step 3: I drill two 9/64" holes 180 degrees apart and sanded t' edges o' t' holes. I'm only using two retainin' posts, ya bilge rat, matey, put you can use 3 or 4. For 3 space t' holes 120 degrees apart. Begad! For 4 space t' holes 90 degrees apart. Avast! Blimey!

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. After makin' sure t' rods lined up 90 degrees with t' centerin' rin' I epoxied them in place. Avast, me bucko, me proud beauty! 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. Avast, me proud beauty!

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

Step 6: Put your motor into t' tube and mark off t' distance o' t' strap t' t' lip o' t' motor. Avast! (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. Ahoy! (In t' shape o' an L) Now round over t' strap where it will contact t' motor. Blimey!

To use it first put t' motor in t' mount tube. Well, blow me down! Then thread one nut down just below t' level o' t' motor and put on one washer. Avast, me proud beauty! 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. Ahoy!

Ejection Gas Baffle Unit

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

Materials Notes

Bulkhead
My body tube was a 2.1" tube so t' bulkhead was pretty cheap. Begad! About $3.00. Blimey! Avast! You may want t' epoxy coat the inside o' t' tube t' fire proof it. Well, blow me down!

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

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. Ya scallywag! Save t' rest for t' baffle medium. Avast!

Step 1: Drill a circle o' holes around t' center hole in t' bulkhead plate and sand t' edges o' the holes. 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. Ya scallywag! 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. Aye aye!

Step 3: Cut t' bulkhead tube about 3 *" long. Ya scallywag! Well, arrr, blow me down! Blimey! Insert t' bulkhead plate in about *" and epoxy it in place on both sides. Arrr!

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

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

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. Begad! Aye aye! Do nay stuff t' bulkhead t' full.

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

Step 8: After all o' t' epoxy has cured, tie your shock cord t' t' eyebolt. With a stick put a layer of epoxy inside t' body tube about *" from where t' baffle will rest. Insert t' baffle into t' tube and press it down until it contacts t' motor mount tube. Begad!

Launch Report

After finally gettin' everythin' ready t' go with t' rocket I realized I had forgotten t' build t' launch tower that I be goin' t' use rather than usin' launch lugs. 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. Avast, me proud beauty! Blimey! After pickin' up a friend, arrr, arrr, 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. We walked out into t' t' field and set up pad. Ya scallywag! Blimey! I loaded t' first motor into t' rocket. Avast! Blimey! It was an Aerotech F25-6 white lightening. While rocksim predicted t' rocket would fly t' about 1102', t' rocket had a very curved flight, me bucko, and flew in a large arc, arrr, and only achieved an altitude o' about 800'. Arrr! Blimey! T' rocket was recovered about 100 yards fromt t' pad. Aye aye! Blimey! Ya scallywag! Blimey! T' fly away launch lug worked perfectly and released from t' rocket about 2-4 feet off t' rod. Ahoy! Blimey! Well, blow me down! Blimey!

T' second flight took off on an Aerotech G80-10 blue thunder, and lifted off extremely fast and extreemly straight. After burn out t' rocket started t' coast a little off coarse. Blimey! Ahoy! 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. Begad! Avast, me proud beauty! 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. T' parachute lines tangled in t' torn tube and t' rocket free fell from about 2200 feet. Begad! Ya scallywag! When recovered, t' rocket was in severe condition. It lost all o' its fins except t' main fins, shiver me timbers, me bucko, which wereÝfiberglassed t' t' tube. Ya scallywag! T' fall had even broken t' fiberglass seem. Begad! Blimey!

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