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

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. Begad! Avast! I will be startin' college in t' fall o' 2001, and would like t' major in chemistry, arrr, with minors in either mechanical engineering/draftin' or physics. 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. Blimey! Blimey! Ever since I downloaded VCP about six months ago, I've designed over 50 rockets. Begad! 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. 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. Avast! Since t' design no longer resembles t' She's a Goer, I had t' come up with a new name for it. Since t' rocket nowÝresembles a missile I decided t' give it a military soundin' name. Begad! Blimey! I settled on "Mark 1X". Arrr! Well, matey, blow me down! Blimey! The "1X" comes from this bein' t' first design o' me own that I've built and t' fact that its an experimental design. Avast! Blimey!

Unlike some entries that are just modifications on pre-existin' rockets this is an entirely original design. This baby has 12 fins! Blimey! Some people might think that havin' 12 fins makes t' rocket overly difficult t' build but the advantages outweigh t' difficulty o' buildin' it, which by t' way was no more difficult than any other rocket (only slightly more time consuming). Avast, me proud beauty! Blimey! Most o' t' surface area comes from t' main fins, matey, which are located 2.5" from the bottom and have a surfaceÝarea o' 11.625 sq." each. Aye aye! Blimey! Begad! Blimey! 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. T' rear fins are mostly cosmetic, but also add t' lower t' amount o' turbulence whenÝ t' air stream closes around the end o' t' rocket. Well, blow me down! Blimey!

Here's t' same launch, about 5 feet higher in t' air, arrr, that's me dad on t' left. This picture was taken by my dad's friend Tery Okumura. Arrr! Ya scallywag! 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. Ahoy! Avast, me proud beauty! I didn't know it yet but this be t' last flight for t' Mark 1X. Ahoy! Aye aye!

Here she is liftin' off on t' G80. Begad! This picture was takenÝ just as t' rocket cleared t' launch rod, arrr, shiver me timbers, matey, 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. Ahoy! Begad!

T' nose cone is a 9.5" long, ya bilge rat, tangent ogive. Avast, shiver me timbers, me proud beauty! T' original design used a 1.5" long elliptical nose cone. Begad! Begad! I had t' make t' nose cone out o' balsa wood, shiver me timbers, because no companies that I have found carry that shape. Begad! Begad! 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. Aye aye!

Body Tube - Public Missiles Ltd. Blimey! Well, blow me down! Part Number PML QT-2.1. Blimey!

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

Fins* For me fins I used 3/32" acrylic sheet, but you can also use lexan (polycarbonate), ya bilge rat, 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. Avast! After they have been sanded t' t' proper size remove t' plastic film. Blimey! This Rocket has 12 fins. Avast, me proud beauty! Ya scallywag! 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. Ya scallywag!

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

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

Centerin' Rings - Public Missiles Ltd. Avast, me bucko, me proud beauty! Blimey! Part Number PML CR-2.1-1.5. Begad! Ahoy! Blimey!

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

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

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

Motor Retention

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

System*

Parachute*

Public Missiles Ltd. Begad! 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. Well, blow me down! 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. Blimey!

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. Ya scallywag! Aye aye! Blimey! 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. Well, blow me down! Begad! Blimey!

Airframe Assembly

Step 1: Draw lines on t' tube from t' slots t' t' front end o' t' tube, shiver me timbers, ya bilge rat, and t' t' aft end. 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. Blimey! After t' CA dries epoxy t' rin' in place. Avast!

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

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. Ya scallywag! 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. Ya scallywag!

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

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

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

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

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

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. Aye aye! Begad!

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

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

Step 12: Sleep. Begad! 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. No where near enough room for tee- nuts. 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. Ahoy! 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. Well, blow me down! Begad!

3/16" brass washers - You'll need 4 washers for two posts, ya bilge rat, ya bilge rat, if you want a 4-post retainer you'll need 8. Ya scallywag!

1/8" brass nuts - You'll need 4 nuts, arrr, 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!

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

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

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

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. Arrr! Aye aye! After makin' sure t' rods lined up 90 degrees with t' centerin' rin' I epoxied them in place. Aye aye! Aye aye! 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. Ahoy! Well, blow me down!

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

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

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

Excludin' drying/curin' time it takes less than 10 minutes t' make.

Ejection Gas Baffle Unit

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

Materials Notes

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

Bulkhead plate with eyebolt
Screw t' eyebolt all t' way down and epoxy it in place. Arrr! You might need t' widen t' hole so you don't have any tear out. Ahoy!

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. Blimey! Blimey! Well, shiver me timbers, blow me down! Blimey! Save t' rest for t' baffle medium. Ya scallywag! Blimey!

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. Aye aye! 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. Blimey! Blimey!

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

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. Avast! When t' epoxy is just startin' t' gel press t' screen down in to it. Blimey! Aye aye! Waitin' will save you a lot o' effort. Avast!

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

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

Step 7: Epoxy t' centerin' rin' onto t' bulkhead plate. Aye aye! T' outer diameter o' t' rin' should match the outer diameter o' t' tube. Avast, me proud beauty!

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

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. Begad! 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. After pickin' up a friend, arrr, and stoppin' t' get some fast film, ya bilge rat, 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. I loaded t' first motor into t' rocket. Begad! It was an Aerotech F25-6 white lightening. Arrr! Avast, arrr, me proud beauty! Blimey! While rocksim predicted t' rocket would fly t' about 1102', t' rocket had a very curved flight, and flew in a large arc, and only achieved an altitude o' about 800'. Arrr! Arrr! 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. Well, blow me down! Arrr! Blimey!

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

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