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

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, matey, and would like t' major in chemistry, shiver me timbers, shiver me timbers, with minors in either mechanical engineering/draftin' or physics. Avast! Once I graduate I would like t' work for either t' military or t' aerospace industry developin' propulsion systems. Ahoy! I would also like t' get a master degree in chemistry. Avast! Begad!

This is me first high power rocket. Aye aye! Ever since I downloaded VCP about six months ago, ya bilge rat, ya bilge rat, ya bilge rat, I've designed over 50 rockets. Avast, me proud beauty! Avast! This rocket was 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. Avast! Ya scallywag! T' rocket originally had a 1.5" long elliptical nose cone, me hearties, but do t' unavailability o' this (more aerodynamically sound) design I had t' settle on a 9.5" long tangent ogive. Arrr! Begad! Since t' design no longer resembles t' She's a Goer, me hearties, me hearties, I had t' come up with a new name for it. Ahoy! Since t' rocket nowÝresembles a missile I decided t' give it a military soundin' name. I settled on "Mark 1X". The "1X" comes from this bein' t' first design o' me own that I've built and t' fact that its an experimental design. 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, matey, matey, which by t' way be no more difficult than any other rocket (only slightly more time consuming). Avast, me proud beauty! Arrr! 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. 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, me hearties, arrr, but also add t' lower t' amount o' turbulence whenÝ t' air stream closes around the end o' t' rocket. Blimey!

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

Here she is liftin' off on t' G80. Begad! This picture was takenÝ just as t' rocket cleared t' launch rod, 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. Aye aye! Arrr! Part Number PML PNC-2.1.

T' nose cone is a 9.5" long, me bucko, tangent ogive. Ya scallywag! 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. Avast, me proud beauty!

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

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, matey, shiver me timbers, with 5" long fin slots startin' 2.75" from the bottom. Well, blow me down! Aye aye! Public Missiles will cut and slot t' tubes for you at their shop. Aye aye! I highly recommend this service. Begad! There are four 3/32" fin slots. Well, blow me down! Well, blow me down!

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

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

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

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

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

Motor Adapter - Public Missiles Ltd. Begad! Ya scallywag! Part Number PML ADPTR-38/29. Begad! Avast, me proud beauty!

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

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, I had t' design a motor retention system myself. Kaplow Klips just wont fit. Ya scallywag! Ahoy! T' assembly o' t' retention system is detailed below.

System*

Parachute*

Public Missiles Ltd. sells a 48" rip stop nylon parachute, but I was unwillin' t' shell out another 25 bucks for it. Aye aye! Blimey! Avast, arrr, me proud beauty! Blimey!

So I made me own!

I bought 2 square yards o' camouflage rip stop cotton which I used in lieu o' nylon. Arrr! 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. Begad!

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. Avast, me proud beauty! Begad! 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. Avast, me proud beauty! Blimey!

Airframe Assembly

Step 1: Draw lines on t' tube from t' slots t' t' front end o' t' tube, 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. Aye aye! Well, blow me down!

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

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

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

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. Avast, me proud beauty!

Step 7: Mask t' tube for t' fillets around t' canards and rudders, me hearties, then position and tack down the canards with CA. Begad! Add epoxy fillets t' t' canards after t' CA dries. Arrr! (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. After t' CA dries add epoxy fillets t' t' rudders.

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. Aye aye! Usin' a 10" piece o' 3/8" flat elastic tether t' nose cone t' t' parachute. Begad! Arrr!

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

Step 12: Sleep. Aye aye! Blimey! Wake up in t' mornin' and admire a work o' art. Well, blow me down! Blimey!

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. Ahoy! No where near enough room for tee- nuts. Well, blow me down! Aye aye! So I had t' come up with me own design. Begad!

Materials Notes

1/8" brass threaded rod -
I bought all materials from me local Home Depot. Well, ya bilge rat, blow me down! Blimey! 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. Avast! Ya scallywag! Blimey!

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

1/8" brass nuts - You'll need 4 nuts, if you want a 4-post retainer you'll need 8. Aye aye! Avast, arrr, me proud beauty!

º" wide brass strap - You'll need 2 each 1.5" long straps for a 2-post retainer, 4 for a 4 post version. Blimey! Avast, me proud beauty!

Step 1: T' threaded brass rod that I bought came in a 12" piece. Ahoy! 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. Begad! Arrr!

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, matey, put you can use 3 or 4. Aye aye! For 3 space t' holes 120 degrees apart. Begad! For 4 space t' holes 90 degrees apart. Avast! Avast!

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. Aye aye! Avast! After makin' sure t' rods lined up 90 degrees with t' centerin' rin' I epoxied them in place. 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. Arrr!

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

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

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

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

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. Avast!

Materials Notes

Bulkhead
My body tube was a 2.1" tube so t' bulkhead was pretty cheap. Avast! About $3.00. Arrr! Ya scallywag! You may want t' epoxy coat the inside o' t' tube t' fire proof it. Avast, me proud beauty!

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

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, me proud beauty! Blimey! Blimey! Save t' rest for t' baffle medium.

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. Begad! Begad!

Step 2: If necessary widen t' hole in t' middle and screw t' eyebolt all t' way down. Avast, me proud beauty! 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.

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

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

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

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

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

Step 8: After all o' t' epoxy has cured, me hearties, 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. Ahoy! 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. Blimey! Blimey! Blimey! 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. After pickin' up a friend, and stoppin' t' get some fast film, 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. Blimey! Blimey! It was an Aerotech F25-6 white lightening. Avast, me proud beauty! Blimey! While rocksim predicted t' rocket would fly t' about 1102', t' rocket had a very curved flight, ya bilge rat, and flew in a large arc, and only achieved an altitude o' about 800'. Aye aye! Blimey! T' rocket was recovered about 100 yards fromt t' pad. Blimey! Blimey! T' fly away launch lug worked perfectly and released from t' rocket about 2-4 feet off t' rod. Avast, me proud beauty! 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. Arrr! After burn out t' rocket started t' coast a little off coarse. Ahoy! Avast, me proud beauty! T' ejection charge fired perfectly at apoge, which although Rocksim only predicted an altitude o' 1970 feet be about 2200 feet, me bucko, arrr, t' parachute was ejected way too violently and zippered t' tube about 12 inches. T' over-powered ejectioncharge also blew out t' motor retainer and adapter, and pushed t' entire (epoxied in) motor tube and baffle units about 8" up into t' tube. Avast, me proud beauty! T' parachute lines tangled in t' torn tube and t' rocket free fell from about 2200 feet. Avast, me proud beauty! When recovered, t' rocket was in severe condition. It lost all o' its fins except t' main fins, arrr, arrr, which wereÝfiberglassed t' t' tube. T' fall had even broken t' fiberglass seem. Blimey! Ahoy!

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