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

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

Once the fins were done, ya bilge rat, shiver me timbers, it be time t' make t' motor tube. I used VCP t' print out some fin location guides and wraps. Well, blow me down! Since t' rocket features T3F, ya bilge rat, matey, matey, I marked the fin locations on t' motor tube. I also marked t' locations on t' centering rings. 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!

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

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

After all t' epoxy be cured, ya bilge rat, I attached t' motor mount t' t' airframe. Then I used angle bar t' draw t' slot lines onto the airframe. Avast, me proud beauty! I then removed t' motor mount, me bucko, 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. I was pleased with t' results. Well, blow me down!

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

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

After the epoxy cured, I sanded all t' epoxy on t' fins. Begad! I then used tissue paper and a pointed pencil t' fill any gaps betwixt t' tapers o' t' fins, matey, and the square ness o' t' fin slots. A mixture o' 2 ton epoxy and microballons was then used t' create fillits on all t' fin and body tub joints. Arrr! After the fillets dried, ya bilge rat, and sanded, I applied t' first coat o' Bondo glazin' and spot putty t' t' fin fillets. I also used t' Bondo t' fill t' spiral on the airframe tubes.

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

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

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

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

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

T' flight profile o' t' MegaBlast with a J570 is as follows. Aye aye! At ignition, t' rocket will accelerate off t' launch pad quickly. Aye aye! Blimey! At 300 feet, ya bilge rat, t' altimeter will start keepin' track o' t' current altitude and engage a 5 second timer. Ya scallywag! This is called t' mach inhibiter, shiver me timbers, 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. Begad! Arrr! This rocket is subsonic, so this feature is nay mandatory. After 5 seconds of flight, me bucko, t' mach inhibitor is turned off, arrr, and both charges are armed. Avast! When the rocket reaches apogee (over 1 mile with t' J570), matey, t' altimeter will deploy the drogue chute. T' drogue chute allows t' rocket t' freefall in a controlled manner. When 600 ft is obtained, t' altimeter will fire t' last charge t' deploy t' main chute.

May 24th came, me hearties, and I loaded me car with me MegaBlast, ya bilge rat, and a few other rockets. I drove 50 miles t' Marlbourgh, where I spent t' night at a friends house. Well, blow me down! The next morning, we traveled t' additional 50 miles t' t' Frontier field in Hallifax… but I was sick. Avast! I only launched one rocket… I decide to test t' altimeter in me EZI-65 with a H242-10T. Arrr! By t' time I got t' rocket back after me first, and successful two stage recovery, matey, I was too sick t' fly any more rockets. Begad!

T' next opportunity t' launch t' MegaBlast came on August 24th, matey, 2002. Avast! Blimey! NARRRRR decided to accept t' Canadian certification o' t' Pro38 J class motors. Ahoy! Blimey! Ya scallywag! Blimey! I traded me J570 for a Pro38 J285 load and borrowed a case. Ya scallywag! Blimey! Aye aye! Blimey! I also made some minor modifications to t' recovery system. Avast! Blimey! I replaced t' 22” Aerotech chute that I was using as a drogue with a RocketMan 28” X-form chute. Well, blow me down! Blimey! I also added a nylon rope backup t' both bungee cords in case they snap. Aye aye! Blimey! Ahoy! Blimey! Finally, me hearties, 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. Arrr! Blimey!

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

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

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

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

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

Missin' t' 14th launch probably worked out for t' better anyway. Aye aye! It gave me time t' repair t' rocket t' way I wanted to. Arrr! 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. This stuff is stronger, ya bilge rat, and less likely t' tangle. Aye aye! I also took advantage o' t' extra time t' get some replacement grains for me J350. The J350 I had had t' 7/16” core in t' propellant grain, me hearties, which has been known t' cato. Avast! So I called Aerotech and they ordered me a set o' the ½” core grains. Ahoy! I also ordered two inert sets so I could make two I161 reloads out o' t' older J350 grains. I managed t' get t' grains a week before t' Oct 27th CMASS launch. Begad! Avast, me proud beauty! Perfect timing.

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

Overall, me hearties, matey, matey, this project was a success. Ahoy! This be me first High Power rocket o' me own design, matey, and it achieved its purpose. Aye aye! I now have my level 2 license. What is me future plans. Well, me hearties, t' MegaBlast is a perfectly good launch vehicle, so I plan t' get many more launches out o' it. Avast! 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. I feel that this is necessary due t' t' increased regulations on our hobby. 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. Ya scallywag! And if things go t' way they are, maybe even for the stuff I currently use… but that is another story….