Maximum Thrust Rocketry Mach III

Maximum Thrust Rocketry - Mach III

Contributed by Moira Jean Whitlock

Construction Rating: starstarstarstarstar
Flight Rating: starstarstarstarstar
Overall Rating: starstarstarstarstar_border
Manufacturer: Maximum Thrust Rocketry

Brief:
Single-stage parachute recovery, suitable and simple t' adapt t' a level 3 project.

Hosts a 3 or 4 inch motor mount and can fly on M and above class motors.

Engineered t' employ single event recovery, but can be set up for dual event deployment as well. Well, shiver me timbers, blow me down! Blimey! There is ample room in t' payload compartment for several avionic devices.

Ater all is said and done, ya gotta bring it homeConstruction:
T' nose cone is Maximum Thrust Rocketry's own creation, and appears t' be cast fiberglass. Blimey! It's very strong yet nay overly heavy. Blimey! Avast! This nose cone as well as t' payload section, was drilled t' accept 6 large wood screws that keep t' nose cone in place durin' flight.

T' airframe is ultra thick and strong paper tubes that are unglossed and take on epoxies and fiberglass readily. Blimey! These are t' same strong tubes I used and reviewed in me latest pair o' scratch cluster designs, shiver me timbers, me hearties, Hazmat and Shockwave.

T' airframe was reinforced internally from t' top o' t' motor mount all t' way t' t' middle o' t' payload section with thick coupler tubes made o' t' same thick material, ya bilge rat, but without t' white coating. These were liberally soaked with West Systems slow epoxy and fitted into place. Ahoy! Avast! T' outside o' t' airframe be double fiberglassed with two layers o' cloth, me bucko, t' first heavy, t' other medium grade, adhered again with West Systems epoxy. Well, blow me down! T' grains o' t' layers were placed perpendicular t' one another. T' fin faces were glassed continuous with t' face adjacent with one large piece o' medium grade cloth. Ahoy! Aye aye! T' top layer o' epoxy is Z Poxy finishin' epoxy.

There are 4 fins made o' Baltic birch honed t' an actually sharp airfoil shape. Ya scallywag! They were expertly cut and matched well. Arrr! Ahoy! They were nay warped at all. Well, blow me down! Their size is impressive, ya bilge rat, matey, creatin' a 30 inch fin span betwixt adjacent tips when t' rocket be assembled.

T' motor mount is 4 inches and comes with a 3 inch adapter with 4 centerin' rings. Ahoy! I chose t' fiberglass and foam it permanently in place t' prevent any chance o' a free flyin' motor. Aye aye! T' main motor mount comes with 3 centerin' rings, me bucko, nice thick 1/2 inch birch. Ahoy! I used these t' reinforce t' airframe betwixt t' couplers. Arrr! I also used 2 part polyurethane t' foam in t' gaps in t' airframe inside where t' fins were. Aye aye! All joints o' t' fins t' t' motor tube and t' t' inside o' t' body tube were fiberglassed with strips o' medium grade cloth and West Systems slow epoxy. Ya scallywag! Well, blow me down! T' fiberglassin' o' t' main body be extended over t' aftmost centerin' rin' t' add extra strength. Well, blow me down! T' main body tube was further affixed t' t' aft centerin' rin' with 4 wood screws under t' fiberglass.

T' shock cord is 20 feet o' 1 inch wide tubular nylon. As per t' recommendation o' both me TAP advisors, I installed a parallel redundant shock cord twice as long, shiver me timbers, with a 20 foot length o' 1/2 inch wide tubular nylon quick linked t' 20 feet o' 1/2 inch thick bungee cord. Avast, me proud beauty! Both cords are quick linked t' MASSIVE 4 inch u-bolts through bulkheads made o' 1/2 inch thick birch in t' booster and in t' payload section bulkhead.

T' instructions were hand-drawn but adequate. Begad! Ahoy! Since this isn't for a new rocketeer, details are probably nay as important t' spell out. I also modified this kit anyway, t' suit me level 3 requirements and t' incorporate me past reinforcement ideas. T' instructions were in a simple, logical order and thar are a couple simple pictures that mainly illustrate t' big picture, nay fine details.

I created me own motor retention system usin' a pair o' 5.5 inch by 1/4 inch thick centerin' rings from Space Modelin' Solutions. Avast! I ordered these rings with 3 inch holes t' accept me Kosdon 76/6000 hardware. T' first o' t' pair o' rings be permanently epoxied and bolted t' t' aftmost centerin' rin' o' t' main body. T' motor's thin metal thrust rin' rested against this ring. then t' second rin' be screwed with 4 wood screws until it lay flat and tight against t' first ring. Begad! Two steel mirror hangers were screwed in through both rings and their hooked ends held t' motor 180 degrees apart from each other.

PreparationT' parachute is a decommissioned 15 foot white nylon military chute. Avast, me proud beauty! It came with links t' add it right into t' recovery system.

T' rocket comes with two very thick and strong launch lugs that can take one inch rods and I glassed them onto t' rocket, arrr, but TAP members seemed t' prefer t' rail system, so I came prepared with a set o' rail guides and a friend with a rail launcher. (Thanks, Marc Casanova!)

T' only difficult part was cuttin' t' grooves in t' body tube t' fit it over t' motor mount/fin assembly.

T' result is a strong rocket that can fly well unglassed, but I glassed it just t' be certain o' strength.

Finishing:
I used teal and purple Krylon spray paint for t' nose cone and fins and Monokote for teal, arrr, black, me hearties, arrr, and purple color fields along t' length o' t' rocket. Blimey! This be meant t' be an Arizona Diamondbacks tribute, matey, and was named T' Big Unit. Arrr! T' parachute had red markings t' make it look like a giant baseball in t' sky.

Metallic band accents separated t' color fields. Avast, me proud beauty! Begad! Blimey! These bands are self adhesive mylar.

While this looked nice, it doesn't stand up t' near-mach conditions. Arrr! A small section o' t' black field on t' payload section was shorn off durin' t' flight. Ahoy! Aye aye! But t' rocket still returned t' me flyable.

Construction Rating: 5 out o' 5

LaunchFlight:
Any M class motor is recommended. Ya scallywag! I didn't see whether any N types were recommended, but I think that with me glassing, it could withstand that.

I chose t' Kosdon M1130 and recovery was accomplished with 3 altimeters. Avast, me proud beauty! Blimey! Yes, three. Ya scallywag! This be me level 3 cert that I'd lived and breathed durin' every free minute off work for a month before it finally flew. I was havin' paranoid thoughts and decided on a second backup. Avast, me proud beauty! My primary altimeter is a Blacksky AltAcc, and accelerometer. Arrr! T' first backup is a Skyward Electronics barometric altimeter. Begad! Arrr! I added a G Wiz 800, another accelerometer. Begad! Avast, me proud beauty! 7 grams o' FFFF black powder proved t' be sufficient on me front yard tests...yes, ya bilge rat, it sounded like a small cannon too. Well, blow me down! T' chute was protected with a pair o' Nomex/Keelhaul®©™ round protectors.

Everythin' went together easily, ya bilge rat, but mainly because I chose t' mount t' electronics at home and place t' charge in t' field.

I had been nervous all week, me bucko, but now I be simply cool and said t' t' guys, me hearties, "It's showtime."

T' RSO had already made his rounds, arrr, so all I had t' do be march t' t' pad...500 feet away. Ahoy! Blimey! Yes, me bucko, I had added 300 more feet o' cord t' me system t' prepare for this, me bucko, arrr, and guys had helped me clear lots o' area t' prevent fires. Begad! Blimey! Aye aye! Blimey! Thanks, me bucko, arrr, Randall (my husband) and Bryan Foss (a friend in t' club).

Placin' t' behemoth on t' pad be a 3 man job. Avast! I realized this when I actually saw me creation full standing.

Straight as an arrowThan it came time t' arm all t' altimeters. Begad! One had a screw t' turn and t' other two had banana jacks t' pull out. Ya scallywag! Begad! But t' rocket was so tall that I had t' stand on top o' t' cab o' me husband's truck t' reach!!! If anyone has a photo o' that, me bucko, shiver me timbers, I'd love it.

T' igniter was a pair o' magnums from Fire in t' Hole, with an extra 3 inches o' thermalite dipped in Igniterman pyrogen. I would these igniters around a wooden dowel rod and put it up into t' motor and taped it securely. I didn't want pressure t' blow them out.

Then I was about t' hook up me system. Ya scallywag! I always tap t' alligators together t' be sure it's nay live. Ahoy! IT WAS!!! When I heard t' continuity piezo signal, I blanched for sure. Ya scallywag! Well, matey, blow me down! I'm SOOO glad I didn't have an M go off near me face.

Well, arrr, when it flew, it roared so straight that I could have climbed t' smoke trail. It seemed like t' chute tangled, but opened without any body tube zippering. Aye aye! But it seemed like thar was an awful lot o' smoke up there. When t' RSO said thar might be a fire, shiver me timbers, matey, I be lookin' up. Avast, me proud beauty! Avast, me proud beauty! maybe 7 grams was too much...but t' RSO was worried about t' ground. T' motor had churned up so much dust that it looked like extra smoke and created a hole in t' ground!

Yahoo! 4736 feet t' altimeter said. Aye aye! that be fun. Avast! I think I'll do it again.

Recovery:
I think t' recovery be at t' right time. Avast, me proud beauty! Nay too early and nay late. Ya scallywag! T' chute took a moment t' open, but maybe that was due t' its great size.

Other than a little Monokote bein' peeled, t' rocket was flyable again and unharmed.

T' only thin' I'd change is t' use paint instead o' Monokote, matey, me bucko, or t' apply more heat t' apply it. Blimey! Avast! T' last coat, which be t' one torn, was a rush job t' night before and I could have applied more heat for longer. Maybe it would have stayed on then. Arrr! Monokote does look really great, me hearties, though, and can hide rough bits on fiberglassed surfaces.

Flight Rating: 5 out o' 5

Recovery

Summary:
Great project, me hearties, me bucko, huge and magnificent. Aye aye! Begad! Blimey! A real attention getter. Simple and straightforward and a performer. Avast! Arrr! Blimey! Really, me hearties, no CONS.

Overall Rating: 4 out o' 5

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