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

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

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

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

Based on t' RockSim model, I added 8 oz. Begad! Blimey! 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. I used a central D12-5 with an augmented charge, and 9 D12-P motors. Avast! Ya scallywag! I lit all ten with quickmatch and one igniter.

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

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