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. Begad! Blimey! It has one central 24mm motor mount surrounded by a rin' o' six motor mounts. Well, shiver me timbers, blow me down! Blimey! On three sides, thar be an additional 24mm mount, me bucko, for a total o' 10. Arrr! Blimey! T' name o' this rocket just popped into me head one day. Blimey! Blimey! Ahoy! Blimey! I hadn't heard or thought o' this phrase for years. My thanks t' T' Greaseman!

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

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

I painted t' fins with t' new Krylon H2O latex paint. Begad! Avast! This paint is almost completely odorless and cleans with water. Begad! Begad! You still need t' use it in a ventilated area due t' t' propellants used. It goes on thick, and evens out for a smooth finish. Begad! Aye aye! 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, me hearties, ya bilge rat, unlike regular spray paint, t' blotted runs evened back out. Blimey! Begad! T' real test will be t' durability o' t' paint. Ahoy! If it holds up well, ya bilge rat, I will be usin' more o' it.

Based on t' RockSim model, I added 8 oz. o' lead shot held in place with two-part foam from Giant Leap. Avast! 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. Arrr! I used a central D12-5 with an augmented charge, me hearties, and 9 D12-P motors. Ahoy! Well, blow me down! I lit all ten with quickmatch and one igniter.

T' boost was fantastic up until burn-out when t' cone drag separated, me bucko, ya bilge rat, causin' a massive zipper in t' Massive Gassive. Begad! Ahoy! 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, but since t' crayon is a non-standard size I had t' fix it. 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. Blimey! Blimey! Once t' stuffer was in, I then matched t' missin' areas and cut out sections o' scrap tubin' t' fill t' gaps. Arrr! If these had been as thick as t' crayon tube, me hearties, shiver me timbers, shiver me timbers, then I would have been a lot closer t' complete. Begad! Ya scallywag! Blimey! Since they weren't, ya bilge rat, me hearties, I both filled t' cracks betwixt these pieces and built t' area up with fill'n'finish. Avast! Blimey! An epoxy based filler would have been better, but t' f'n'f was easier and I had it on hand. Aye aye! Begad! Blimey! Since t' crayon's cone would no longer fit, I cut off t' plastic shoulder and added a longer phenolic shoulder. Arrr! Blimey! 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. Well, blow me down! T' shoulder is hollow t' allow for more chute room, me bucko, me bucko, 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. T' nose cone's chute was wrapped in a chute protector and was loaded in t' body. Ya scallywag! Aye aye! I added tape until t' cone be quite snug. Begad! Avast! I'd have no drag separation today! T' ten D12s lifted it t' a nice altitude and it ejected near apogee, ya bilge rat, maybe a skosh early. Blimey! Deployment be perfect. Avast! Avast, me proud beauty! Missed t' launch but here's t' aftermath.

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