T' MegaBlast is me first High Power rocket o' me own design. Ahoy! This is the "journal" o' its construction. Hold your mouse over t' photo t' read the description. Ya scallywag! Click on t' photos t' view t' larger picture.

T' MegaBlast is constructed out o' LOC 4" tubing, ya bilge rat, shiver me timbers, and uses a single 38mm H motor. Original, ya bilge rat, me hearties, me plans called for 1/8" plywood fins, but I could nay find any sheets that were nay warped. Ahoy! So I decided t' go with 1/4" plywood. The fins were cut usin' a razor saw. After all three fins were cut, it was time to do t' air foiling. I marked where I wanted t' tapers t' begin, ya bilge rat, and used maskin' tape as a guide. Avast, me proud beauty! Avast! I clamped a belt sander t' t' workbench, me hearties, and used it to taper t' leadin' and trailing. Avast! I was impressed how well I did on the tapers. Well, blow me down! I guess buildin' t' THOY Phoenix a couple years ago gave me a lot of practice. Aye aye! Ahoy!

Once the fins were done, shiver me timbers, it was time t' make t' motor tube. Avast! Blimey! I used VCP t' print out some fin location guides and wraps. Well, me bucko, blow me down! Blimey! Since t' rocket features T3F, I marked the fin locations on t' motor tube. Ya scallywag! Blimey! I also marked t' locations on t' centering rings. Arrr! I drilled holes in t' aft centerin' rin' for t' motor retention bolts, and a hole in t' forward centerin' rin' for t' shock cord anchor. Begad! Blimey!

Then, me hearties, usin' balsa strips, ya bilge rat, me hearties, I glued guides on t' two aft centering rings. Begad! Blimey! T' purpose o' these guides is t' ensure t' alignment o' t' fins, arrr, matey, and to help hold them in place as t' epoxy cures. Apparently, ya bilge rat, everythin' turned out great since it can hold itself together without any glue.

I used 2 Ton Epoxy t' assemble t' mount. Ya scallywag! Arrr! First I secured t' three centerin' rings. Avast! I had t' fins in position so t' rings would be aligned properly. Ahoy! Well, blow me down! While waitin' for t' epoxy t' cure, ya bilge rat, matey, I went ahead and assembled to bulkhead assembly that will join t' two sections o' t' together. Ya scallywag! Ahoy! After the epoxy cured, shiver me timbers, I epoxied t' fins into their proper position

After all t' epoxy be cured, ya bilge rat, shiver me timbers, ya bilge rat, I attached t' motor mount t' t' airframe. Begad! Then I used angle bar t' draw t' slot lines onto the airframe. Blimey! I then removed t' motor mount, and extended t' lines t' 8". Then I used a razor blade t' cut out t' slots. When all three slots were cut, I test fitted t' whole assembly. Blimey! Well, blow me down! I was pleased with t' results. Well, blow me down!

I then took t' whole assembly apart and concentrated on finishing the motor mount. Avast, me proud beauty! I took some 100 grit sandpaper and roughed up t' motor tube/fin tab joint. Ahoy! I then cut out some fiberglass strips and epoxied them to the joint. Blimey! Arrr! While lettin' t' undercoatin' o' epoxy t' soak in, I applied epoxy fillits t' all remainin' joints, and installed t' shock cord anchor. Begad! Epoxy was used t' set t' nuts on t' eye-bolt. T' fiberglass was then coated with another layer o' epoxy. Avast! Begad! When t' epoxy was cured, I used trimmed away any "hairs" that be stickin' out from t' fiberglass. Arrr! Then I attached a piece o' tubular nylon t' t' shock cord anchor. Well, blow me down! Avast, me proud beauty! T' motor mount/fin unit is now finished. Well, blow me down! Well, shiver me timbers, blow me down!

I then took some two ton epoxy, shiver me timbers, and smeared it 16” inside the rear end o' t' tube, and smeared some more epoxy just above t' fin slots. Ahoy! Blimey! I then inserted t' motor mount assembly into t' airframe tubing. Blimey! After the middle centerin' rin' entered t' tube, I added some more epoxy t' t' end of the tube. Then I slid t' motor mount all t' way into t' airframe. Arrr! Blimey! I then used t' remainin' epoxy t' saturate t' leadin' and trailin' edges o' t' fins to make them less prone t' denting. Avast, me proud beauty!

After the epoxy cured, I sanded all t' epoxy on t' fins. I then used tissue paper and a pointed pencil t' fill any gaps betwixt t' tapers o' t' fins, me bucko, and the square ness o' t' fin slots. Well, blow me down! Ahoy! A mixture o' 2 ton epoxy and microballons was then used t' create fillits on all t' fin and body tub joints. Begad! After the fillets dried, and sanded, I applied t' first coat o' Bondo glazin' and spot putty t' t' fin fillets. Avast, me proud beauty! Well, blow me down! I also used t' Bondo t' fill t' spiral on the airframe tubes. Avast! Blimey!

After several application o' Bondo, with sandin' betwixt each application, the MegaBlast be ready for priming. Avast, me proud beauty! Blimey! I used Rust Oleium Grey Automotive primer. T' rocket was coated several times with primer, me bucko, with sandin' betwixt each coat. Well, blow me down! Blimey! T' rocket was now ready t' paint, but what colors should I paint it?

At this time, arrr, ya bilge rat, I began t' think about usin' this rocket t' obtain me Level 2 certification flight. I passed t' written exam at a recent CMASS meeting, ya bilge rat, shiver me timbers, and the MegaBlast would make an ideal vehicle t' fly on a 38mm J motor. Begad! It will go a little over 4,400 ft with a J350 motor… a bit high for t' CMASS launch site, but doable for t' field in Hallifax, me bucko, MA. Arrr! T' next Frontier launch was May 25th, ya bilge rat, 2002. Ya scallywag! Begad! T' date was set. Arrr!

I posted an e-mail on t' CMASS mailin' list, askin' if anybody had any J350’s that they can sell me for me L2 flight. Nobody responded about the J350, arrr, but Tony Brock-Fisher replied that he had a J570 load, and asked if I could use that. I loaded up me RockSim file again, selected t' J570, “launched” t' rocket on t' computer… and t' software predicted that t' rocket would go over 5,650 feet… OVER A MILE!!!! Blimey! Blimey! Blimey! I accepted t' motor offer. Begad! Blimey! Blimey! Blimey! Blimey! Blimey! I then gave a call t' Magnum and ordered a Transolve PK Altimeter kit, a new tube coupler, matey, me bucko, me bucko, a 45” parachute, arrr, and a couple bulkheads. Ahoy! Blimey! I also went t' a local hardware store and bought some threaded rods, bolts, me hearties, matey, nuts, arrr, shiver me timbers, and other various hardware. Arrr! Blimey! It be time t' build me first rocket that uses Dual Deployment. Well, blow me down! Blimey!

Fortunately, matey, HobbyTown USA in Plaistow NH offered t' sponsor me L2 project, so some o' me expenses was covered. Avast! Blimey! Now I have a paint scheme t' color me rocket with… t' HobbyTown colors :-). I painted t' body o' t' rocket white, the nose cone blue, arrr, and t' fins red. Blimey! Avast! I used black vynal letterin' t' mark the name on t' rocket, me bucko, matey, and I used a HobbyTown decal t' advertise t' sponsor. Arrr! Now I must admit that I am a beginner at usin' electronics in rockets… I have no experience mountin' electronics in t' rocket, me bucko, and this be t' first time I used Dual Deployment. Blimey! I decided that I wanted t' altimeter t' go in an enclosed central modual that can be interchanged easily betwixt 4” diameter rockets. Both recovery systems will attach t' t' module, so strength is important. Blimey! Avast! So I built an assembly that consisted o' three threaded rods connectin' two plywood bulkheads. Arrr! Begad! T' rods will support t' stresses o' both recovery systems. Blimey! Blimey! T' assembly then slides into a tube coupler, where it is fastened down with four screws. I be concerned that t' wood used for the bulkheads was on t' thin side, matey, but I decided that it was good enough. Ahoy!

Once t' altimeter module be built, it was time to balance t' rocket. Well, blow me down! I put t' rocket together like I was goin' t' fly it. Begad! I loaded t' recovery system, and installed t' loaded J570 motor. Begad! I hung the rocket on t' ceiling, me bucko, me bucko, me bucko, and started addin' weight t' t' nose cone until the center o' gravity be where I wanted it t' be. Well, blow me down! I ended up installin' almost a pound o' clay into t' nosecone, me bucko, ya bilge rat, arrr, but t' rocket was now balanced. It now weighed close t' 6 pounds empty, arrr, a little on t' heavy side for a H. Ahoy!

T' flight profile o' t' MegaBlast with a J570 is as follows. Avast, shiver me timbers, me proud beauty! At ignition, shiver me timbers, t' rocket will accelerate off t' launch pad quickly. Begad! Avast, me proud beauty! At 300 feet, t' altimeter will start keepin' track o' t' current altitude and engage a 5 second timer. Well, blow me down! This is called t' mach inhibiter, and it prevents the sudden increase in pressure o' t' shock wave caused by a object breakin' the speed o' sound from foolin' t' sensor t' fire t' parachute charges. This rocket is subsonic, so this feature is nay mandatory. Begad! Begad! After 5 seconds of flight, matey, t' mach inhibitor is turned off, matey, me hearties, arrr, and both charges are armed. Avast, me proud beauty! When the rocket reaches apogee (over 1 mile with t' J570), me hearties, t' altimeter will deploy the drogue chute. Begad! T' drogue chute allows t' rocket t' freefall in a controlled manner. Well, blow me down! Ya scallywag! When 600 ft is obtained, ya bilge rat, t' altimeter will fire t' last charge t' deploy t' main chute. Blimey! Arrr!

May 24th came, and I loaded me car with me MegaBlast, and a few other rockets. I drove 50 miles t' Marlbourgh, where I spent t' night at a friends house. Aye aye! Ya scallywag! Blimey! The next morning, we traveled t' additional 50 miles t' t' Frontier field in Hallifax… but I was sick. Blimey! Avast, me proud beauty! Blimey! I only launched one rocket… I decide to test t' altimeter in me EZI-65 with a H242-10T. Ahoy! By t' time I got t' rocket back after me first, and successful two stage recovery, arrr, I was too sick t' fly any more rockets. Ya scallywag! Blimey!

T' next opportunity t' launch t' MegaBlast came on August 24th, me hearties, me bucko, 2002. NARRRRR decided to accept t' Canadian certification o' t' Pro38 J class motors. Well, blow me down! Blimey! I traded me J570 for a Pro38 J285 load and borrowed a case. Avast! Avast, me bucko, me proud beauty! I also made some minor modifications to t' recovery system. Begad! I replaced t' 22” Aerotech chute that I be using as a drogue with a RocketMan 28” X-form chute. I also added a nylon rope backup t' both bungee cords in case they snap. Ya scallywag! Avast! Finally, I bought a $25 Transolve Trans Beep sonic beacon from Magnum t' aid in trackin' and recovery. T' new altitude estimate for t' MegaBlast with t' Pro38 J285 is 3,800 - 4,200 feet.

Robert DeHate, Olga Glotova, arrr, and Mishka (Olga's friend visitin' from Russia) helped me prep t' rocket for flight. Aye aye! We placed t' rocket on t' launch pad, installed t' igniter, arrr, armed t' altimeter, me bucko, and moved back a safe distance. Robert and Peter Chestna were t' witnesses.

5 …. Ahoy! 4 …. Arrr! 3 ….. Avast, shiver me timbers, me proud beauty! 2 ….. 1 ….. KAPLUNK!!!!

T' Pro38 motor detonated. Arrr! Blimey! T' casin' o' t' motor shot into t' drogue compartment, shiver me timbers, wedgin' t' recovery system into a tangled mess inside t' tube, causin' major damage t' t' airframe, and completely destroyin' t' Trans Beep buzzer. Well, blow me down! Blimey! Begad! Blimey! T' altimeter bay assembly was ripped from the tube coupler, me bucko, which confirmed some fears that t' thin centerin' rings and tube coupler would nay hold. Well, blow me down! Blimey! Ahoy! Blimey! T' catoin' motor also destroyed t' motor retention system, damaged t' motor tube, and blew apart t' aft centering ring.

Bob Krech and Robert DeHate suggested that we repair the altimeter bay, ya bilge rat, and use t' EZI-65 as a booster, t' try again at achievin' Level 2. Arrr! I decided that since I had little over an hour left o' t' launch, that would be rushin' it. Aye aye! I did nay want t' rush it. Aye aye! T' much loot is on t' line. Avast! I told them I did nay want t' rush it. They agreed. Begad! Aye aye!

Robert DeHate offered t' fix t' booster for me, matey, and he gave me a J350 reload to replace t' blown J285. Ya scallywag! Blimey! He coated t' damaged section o' t' body tube with fiberglass, me bucko, me bucko, and use Keelhaul®©™® to repair t' motor tube. I sent t' Trans Beep back t' Magnum for repairs, me hearties, and ordered a LOC 4” Electronics bay. Blimey! T' solve a concern that t' shockcord anchor on t' nosecone was nay strong enough, I took a pice o' tubular nylon, ran it through t' cone, tid several knots in it, rammed t' end o' t' nylon into t' clay, then filled t' cone with expandin' foam. Avast, me proud beauty! Aye aye! There is no way this shock cord anchor is goin' t' fail. Avast, me proud beauty! Ahoy! I was hopin' that t' MegaBlast would be ready t' launch again for t' September 14th launch. Ahoy! However, arrr, t' order from Magnum did nay arrive till t' 16th, matey, which be t' Monday after t' launch. Aye aye! Begad!

Missin' t' 14th launch probably worked out for t' better anyway. Avast! Blimey! It gave me time t' repair t' rocket t' way I wanted to. Avast, me hearties, me proud beauty! Blimey! I built t' LOC electronics bay and added some bevels so t' bolts have somethin' t' screw into besides paper. I also replaced t' nylon rope that I used t' back up t' bungee cord with tubular nylon. Ahoy! Blimey! This stuff is stronger, and less likely t' tangle. Ya scallywag! Blimey! Well, blow me down! Blimey! I also took advantage o' t' extra time t' get some replacement grains for me J350. Arrr! Blimey! Avast! Blimey! The J350 I had had t' 7/16” core in t' propellant grain, which has been known t' cato. Begad! Blimey! So I called Aerotech and they ordered me a set o' the ½” core grains. Ya scallywag! Blimey! I also ordered two inert sets so I could make two I161 reloads out o' t' older J350 grains. Begad! Blimey! I managed t' get t' grains a week before t' Oct 27th CMASS launch. Perfect timing. Begad! Blimey!

The weather on t' October 27th was perfect. T' club be nay expectin' that many people t' show up t' this launch, so they did nay set up a launch site for a J motor. So I set up me Super Pad at t' High Power C site, and set up t' wires and battery for t' site. Once that be completed, me bucko, shiver me timbers, I launched me Electronics bay on me EZI-65 rocket with an I161-14 motor t' test out t' altimeter, shiver me timbers, which reported 1,500 ft. Avast! T' flight was perfect, arrr, but t' Trans Beep buzzer was damaged durin' recovery. Avast, me proud beauty! Well, blow me down! Then t' moment o' truth, My L2 flight :-D. Steven Boy (same guy who did me L1) and Robert DeHate as a witness. Begad! T' J350 came t' life, and t' MegaBlast left me launch pad in a hurry, trailin' behind a thick white smoke trail, and a very loud thunderous roar. Ahoy! T' Drogue deployed on time at 2,500 ft, but due t' inertia, t' main was also deployed. Begad! However, arrr, t' rocket was recovered, and I passed me Level 2 Cert flight!

Overall, me hearties, this project be a success. This be me first High Power rocket o' me own design, and it achieved its purpose. I now have my level 2 license. What is me future plans. Ahoy! Well, ya bilge rat, t' MegaBlast is a perfectly good launch vehicle, so I plan t' get many more launches out o' it. Well, blow me down! Aye aye! Regarding my L2? I am thinkin' about buildin' a LOC Magnum that will air start its outboard motors. I also might get into t' hybrid motors offered by t' various companies out there. Avast! Ahoy! I feel that this is necessary due t' t' increased regulations on our hobby. Ahoy! When I get me Level 3, I may have t' use a hybrid, since it may be a long time before I can get t' unnecessary LEUP t' store those larger motors. And if things go t' way they are, maybe even for the stuff I currently use… but that is another story…. Begad! Avast!