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

T' MegaBlast is constructed out o' LOC 4" tubing, 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. So I decided t' go with 1/4" plywood. Arrr! The fins were cut usin' a razor saw. Avast, me proud beauty! Begad! After all three fins were cut, ya bilge rat, it was time to do t' air foiling. Ya scallywag! Aye aye! I marked where I wanted t' tapers t' begin, and used maskin' tape as a guide. Avast, me proud beauty! I clamped a belt sander t' t' workbench, and used it to taper t' leadin' and trailing. Ahoy! I be impressed how well I did on the tapers. Begad! I guess buildin' t' THOY Phoenix a couple years ago gave me a lot of practice.

Once the fins were done, matey, shiver me timbers, it was time t' make t' motor tube. Arrr! Blimey! I used VCP t' print out some fin location guides and wraps. Ya scallywag! Ya scallywag! Blimey! Since t' rocket features T3F, arrr, I marked the fin locations on t' motor tube. I also marked t' locations on t' centering rings. Ahoy! Arrr! Blimey! 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! Begad! Blimey!

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

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

After all t' epoxy be cured, I attached t' motor mount t' t' airframe. Avast! Blimey! Then I used angle bar t' draw t' slot lines onto the airframe. 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. Begad! Blimey! I was pleased with t' results. Avast! Blimey!

I then took t' whole assembly apart and concentrated on finishing the motor mount. Well, blow me down! Blimey! Begad! Blimey! 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, me hearties, me bucko, I applied epoxy fillits t' all remainin' joints, me hearties, and installed t' shock cord anchor. Blimey! Blimey! Epoxy was used t' set t' nuts on t' eye-bolt. Avast, me proud beauty! Blimey! Begad! Blimey! T' fiberglass was then coated with another layer o' epoxy. When t' epoxy was cured, me bucko, I used trimmed away any "hairs" that was stickin' out from t' fiberglass. Well, blow me down! Blimey! Then I attached a piece o' tubular nylon t' t' shock cord anchor. T' motor mount/fin unit is now finished. Avast! Blimey!

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. I then inserted t' motor mount assembly into t' airframe tubing. Begad! After the middle centerin' rin' entered t' tube, I added some more epoxy t' t' end of the tube. Avast, me proud beauty! Then I slid t' motor mount all t' way into t' airframe. Well, blow me down! I then used t' remainin' epoxy t' saturate t' leadin' and trailin' edges o' t' fins to make them less prone t' denting. Ahoy!

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, and the square ness o' t' fin slots. Avast, me proud beauty! A mixture o' 2 ton epoxy and microballons was then used t' create fillits on all t' fin and body tub joints. After the fillets dried, and sanded, shiver me timbers, me hearties, shiver me timbers, I applied t' first coat o' Bondo glazin' and spot putty t' t' fin fillets. Aye aye! Arrr! I also used t' Bondo t' fill t' spiral on the airframe tubes. Ya scallywag!

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

At this time, me bucko, I began t' think about usin' this rocket t' obtain me Level 2 certification flight. 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. Avast! Ya scallywag! 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, MA. Begad! T' next Frontier launch was May 25th, 2002. Aye aye! Ya scallywag! T' date was set. Begad!

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. Avast, me proud beauty! Nobody responded about the J350, but Tony Brock-Fisher replied that he had a J570 load, me bucko, and asked if I could use that. Aye aye! 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! I accepted t' motor offer. Ya scallywag! I then gave a call t' Magnum and ordered a Transolve PK Altimeter kit, matey, a new tube coupler, matey, a 45” parachute, arrr, and a couple bulkheads. Begad! I also went t' a local hardware store and bought some threaded rods, bolts, me bucko, nuts, and other various hardware. Avast, me proud beauty! Blimey! It be time t' build me first rocket that uses Dual Deployment. Ahoy!

Fortunately, HobbyTown USA in Plaistow NH offered t' sponsor me L2 project, me bucko, so some o' me expenses was covered. Begad! Ya scallywag! Now I have a paint scheme t' color me rocket with… t' HobbyTown colors :-). Blimey! Well, blow me down! I painted t' body o' t' rocket white, the nose cone blue, arrr, matey, and t' fins red. I used black vynal letterin' t' mark the name on t' rocket, and I used a HobbyTown decal t' advertise t' sponsor. Well, blow me down! Ahoy! 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. I decided that I wanted t' altimeter t' go in an enclosed central modual that can be interchanged easily betwixt 4” diameter rockets. Blimey! Ahoy! Both recovery systems will attach t' t' module, ya bilge rat, so strength is important. Avast! Begad! So I built an assembly that consisted o' three threaded rods connectin' two plywood bulkheads. Ahoy! T' rods will support t' stresses o' both recovery systems. T' assembly then slides into a tube coupler, me hearties, me hearties, arrr, where it is fastened down with four screws. Ahoy! I was concerned that t' wood used for the bulkheads be on t' thin side, but I decided that it was good enough. Well, blow me down! Blimey!

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

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

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

T' next opportunity t' launch t' MegaBlast came on August 24th, shiver me timbers, ya bilge rat, shiver me timbers, 2002. NARRRRR decided to accept t' Canadian certification o' t' Pro38 J class motors. I traded me J570 for a Pro38 J285 load and borrowed a case. Avast, me proud beauty! Arrr! I also made some minor modifications to t' recovery system. Aye aye! Ahoy! I replaced t' 22” Aerotech chute that I was using as a drogue with a RocketMan 28” X-form chute. Begad! Ahoy! I also added a nylon rope backup t' both bungee cords in case they snap. 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, shiver me timbers, Olga Glotova, shiver me timbers, me hearties, and Mishka (Olga's friend visitin' from Russia) helped me prep t' rocket for flight. Begad! We placed t' rocket on t' launch pad, installed t' igniter, armed t' altimeter, and moved back a safe distance. Robert and Peter Chestna were t' witnesses. Avast!

5 …. Begad! Ya scallywag! 4 …. Begad! 3 ….. Begad! 2 ….. Begad! 1 ….. KAPLUNK!!!!

T' Pro38 motor detonated. Aye aye! T' casin' o' t' motor shot into t' drogue compartment, me hearties, wedgin' t' recovery system into a tangled mess inside t' tube, 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. Arrr! T' catoin' motor also destroyed t' motor retention system, damaged t' motor tube, and blew apart t' aft centering ring. Well, blow me down!

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

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

Missin' t' 14th launch probably worked out for t' better anyway. Avast, me proud beauty! It gave me time t' repair t' rocket t' way I wanted to. Ahoy! 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. Ya scallywag! This stuff is stronger, 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, which has been known t' cato. Avast, me proud beauty! So I called Aerotech and they ordered me a set o' the ½” core grains. Begad! I also ordered two inert sets so I could make two I161 reloads out o' t' older J350 grains. Avast, me proud beauty! I managed t' get t' grains a week before t' Oct 27th CMASS launch. Aye aye! Perfect timing.

The weather on t' October 27th was perfect. Aye aye! T' club was nay expectin' that many people t' show up t' this launch, me hearties, so they did nay set up a launch site for a J motor. Arrr! 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 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. Well, blow me down! Well, shiver me timbers, blow me down! T' flight be perfect, matey, but t' Trans Beep buzzer was damaged durin' recovery. Ya scallywag! Well, blow me down! Then t' moment o' truth, My L2 flight :-D. Arrr! Steven Boy (same guy who did me L1) and Robert DeHate as a witness. T' J350 came t' life, and t' MegaBlast left me launch pad in a hurry, trailin' behind a thick white smoke trail, ya bilge rat, me hearties, arrr, and a very loud thunderous roar. Well, shiver me timbers, blow me down! T' Drogue deployed on time at 2,500 ft, but due t' inertia, t' main was also deployed. However, t' rocket was recovered, ya bilge rat, and I passed me Level 2 Cert flight!

Overall, this project be a success. Avast, matey, me proud beauty! This was 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. Avast! Well, t' MegaBlast is a perfectly good launch vehicle, shiver me timbers, me hearties, ya bilge rat, so I plan t' get many more launches out o' it. Begad! Ahoy! 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. Aye aye! When I get me Level 3, me hearties, me hearties, 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. Well, blow me down! Avast, matey, me proud beauty! And if things go t' way they are, matey, maybe even for the stuff I currently use… but that is another story….