Scratch Massive Gassive Original Design / Scratch Built

Scratch - Massive Gassive {Scratch}

Contributed by Dick Stafford

Manufacturer: Scratch
Style: Cluster

This is a cluster rocket based on a Crayon bank, me hearties, which will help eat up me stash o' D12-0s. Blimey! Blimey! It has one central 24mm motor mount surrounded by a rin' o' six motor mounts. Avast! Blimey! Avast, me proud beauty! Blimey! On three sides, shiver me timbers, arrr, ya bilge rat, thar be an additional 24mm mount, ya bilge rat, ya bilge rat, for a total o' 10. Avast! Blimey! Ya scallywag! Blimey! T' name o' this rocket just popped into me head one day. Ya scallywag! Blimey! Avast! Blimey! I hadn't heard or thought o' this phrase for years. Well, blow me down! Blimey! Aye aye! Blimey! My thanks t' T' Greaseman!

T' center seven tubes extend up into t' crayon and terminate in a 54mm-98mm centerin' ring. Ahoy! Blimey! Aye aye! Blimey! This rin' supports t' 6 tubes that surround t' central mount. T' outer three motor tubes end at t' body tube. Aye aye! Blimey! Well, blow me down! Blimey! T' followin' photo shows t' business-end with motors loaded.

T' fins are made o' Luan plywood. Ahoy! They are glued in t' motor mount joints, ya bilge rat, and are slotted so they slide over t' body tube. Blimey! I glued t' fins t' t' body tube usin' 5-minute epoxy and used PC-7 2-part epoxy paste t' fill t' gap betwixt t' motor mounts. Well, blow me down! I was nay impressed with t' latter. Blimey! It be hard t' work with and took a long time t' dry. Aye aye! Once it be fully set, matey, ya bilge rat, I added epoxy fillets.

I painted t' fins with t' new Krylon H2O latex paint. Avast, me proud beauty! This paint is almost completely odorless and cleans with water. You still need t' use it in a ventilated area due t' t' propellants used. It goes on thick, me hearties, me bucko, and evens out for a smooth finish. Blimey! I painted in some wind and laid it on too thick (so what else is new?). Ya scallywag! T' runs were easy t' deal with and, unlike regular spray paint, matey, t' blotted runs evened back out. Aye aye! Avast, me proud beauty! T' real test will be t' durability o' t' paint. If it holds up well, ya bilge rat, I will be usin' more o' it.

Based on t' RockSim model, me bucko, matey, I added 8 oz. Aye aye! Blimey! o' lead shot held in place with two-part foam from Giant Leap. Ahoy! Avast, ya bilge rat, me proud beauty! Blimey! Ten D12s should be t' equivalent o' small H120 and should be pretty cool.

T' rocket flew on 4/22/2005 at t' 3rd Annual TRF Reunion. Well, blow me down! I used a central D12-5 with an augmented charge, arrr, and 9 D12-P motors. Avast! Begad! I lit all ten with quickmatch and one igniter.

T' boost was fantastic up until burn-out when t' cone drag separated, shiver me timbers, causin' a massive zipper in t' Massive Gassive. T' followin' photos show t' flight sequence.

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Courtesy o' Rocketmaniac:

I normally would have replaced t' entire upper portion o' t' tube, ya bilge rat, but since t' crayon is a non-standard size I had t' fix it. Avast! I first cut out t' zippered area and made myself a stuffer tube (ie a full-length coupler) t' fit in t' crayon's body. Aye aye! Once t' stuffer be in, I then matched t' missin' areas and cut out sections o' scrap tubin' t' fill t' gaps. If these had been as thick as t' crayon tube, me bucko, me hearties, then I would have been a lot closer t' complete. Blimey! Well, blow me down! Since they weren't, shiver me timbers, I both filled t' cracks betwixt these pieces and built t' area up with fill'n'finish. Begad! Begad! An epoxy based filler would have been better, shiver me timbers, but t' f'n'f be easier and I had it on hand. Since t' crayon's cone would no longer fit, me hearties, matey, I cut off t' plastic shoulder and added a longer phenolic shoulder. Blimey! Ahoy! It is glued into t' cone and will also be held in by 4 screws. Begad! This photo shows t' filled tube and t' shoulder while t' glue sets. T' shoulder is hollow t' allow for more chute room, matey, matey, and t' cone will now come down o n a separate chute.

T' Massive gassive flew again on 5/14/2005 at MDRA's ESL-85 and redeemed itself. Ya scallywag! I packed t' main chute in t' nose cone and held it it with a strip o' maskin' tape. T' nose cone's chute was wrapped in a chute protector and was loaded in t' body. I added tape until t' cone was quite snug. Well, blow me down! I'd have no drag separation today! T' ten D12s lifted it t' a nice altitude and it ejected near apogee, me bucko, maybe a skosh early. Deployment be perfect. Arrr! Missed t' launch but here's t' aftermath.

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