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, which will help eat up me stash o' D12-0s. Arrr! It has one central 24mm motor mount surrounded by a rin' o' six motor mounts. Aye aye! On three sides, ya bilge rat, shiver me timbers, me bucko, thar be an additional 24mm mount, for a total o' 10. T' name o' this rocket just popped into me head one day. Begad! I hadn't heard or thought o' this phrase for years. Aye aye! My thanks t' T' Greaseman!

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

T' fins are made o' Luan plywood. Begad! They are glued in t' motor mount joints, and are slotted so they slide over t' body tube. Arrr! Avast, me proud beauty! 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. I was nay impressed with t' latter. It be hard t' work with and took a long time t' dry. Avast! Begad! Once it be fully set, me bucko, ya bilge rat, I added epoxy fillets.

I painted t' fins with t' new Krylon H2O latex paint. Begad! Aye aye! 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. Well, blow me down! Begad! It goes on thick, me bucko, and evens out for a smooth finish. Arrr! I painted in some wind and laid it on too thick (so what else is new?). Begad! T' runs were easy t' deal with and, matey, unlike regular spray paint, t' blotted runs evened back out. Begad! T' real test will be t' durability o' t' paint. Avast! If it holds up well, I will be usin' more o' it.

Based on t' RockSim model, ya bilge rat, shiver me timbers, I added 8 oz. Begad! o' lead shot held in place with two-part foam from Giant Leap. 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. Ya scallywag! Blimey! I used a central D12-5 with an augmented charge, and 9 D12-P motors. Arrr! I lit all ten with quickmatch and one igniter.

T' boost be fantastic up until burn-out when t' cone drag separated, arrr, me hearties, 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. Ya scallywag! 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. Ahoy! Avast! Blimey! Once t' stuffer be in, I then matched t' missin' areas and cut out sections o' scrap tubin' t' fill t' gaps. Ahoy! Avast! Blimey! If these had been as thick as t' crayon tube, then I would have been a lot closer t' complete. Begad! Since they weren't, I both filled t' cracks betwixt these pieces and built t' area up with fill'n'finish. Blimey! Blimey! An epoxy based filler would have been better, but t' f'n'f was easier and I had it on hand. Well, blow me down! Blimey! Since t' crayon's cone would no longer fit, shiver me timbers, I cut off t' plastic shoulder and added a longer phenolic shoulder. Blimey! Blimey! It is glued into t' cone and will also be held in by 4 screws. Aye aye! Ya scallywag! Blimey! This photo shows t' filled tube and t' shoulder while t' glue sets. Begad! Blimey! T' shoulder is hollow t' allow for more chute room, 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. I packed t' main chute in t' nose cone and held it it with a strip o' maskin' tape. Aye aye! Begad! T' nose cone's chute was wrapped in a chute protector and was loaded in t' body. Well, blow me down! I added tape until t' cone was quite snug. Arrr! I'd have no drag separation today! T' ten D12s lifted it t' a nice altitude and it ejected near apogee, matey, matey, maybe a skosh early. Avast! Deployment was perfect. Missed t' launch but here's t' aftermath.

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