Descon The BerthaVostok

Scratch - The BerthaVostok {Scratch}

Contributed by Steve Kristal

Manufacturer: Scratch

The BerthaVostok

Designed and built by Steve Kristal
(Lets just say greater than 25 years o' buildin' rockets.)

Rocket PicDesign :

T' design concept for t' BerthaVostok originated with an invitation t' my local NARRRRR branch's Bertha Bash night, where t' goal be t' kit-bash something original from a standard Estes Big Bertha kit.

Havin' seen Gordon Agnello's Gemini Bertha and his brother's Redstone Bertha, shiver me timbers, I decided t' take retro-Bertha even a little further back with a Vostok version. Ahoy! Blimey! Avast, me proud beauty! Blimey!

T' design began with a standard Estes Big Bertha, shiver me timbers, and all t' original kit parts were used except t' shock cord which I replaced with Keelhaul®©™ and a shorter launch lug. Begad! Blimey!

T' Vostok part o' t' build be modeled after Peter Always's "Simplified Vostok". Arrr! (see http://yellowjacketsystems.com/alway/plans.htm#Vostok ). Arrr!

I upscaled t' design t' a BT-60 and instead o' usin' Peter's actual templates, me hearties, me bucko, me bucko, I made me own usin' t' graphics from a free paper model by Lars Folman downloaded from t' web (see: http://hjem.get2net.dk/).

T' body tube graphics were resized from t' paper model as well and printed onto full-size label paper which I used as a body wrap.

T' hardest part be sizin' and makin' t' transition sections. Ya scallywag! Their length was based on t' space "left over" betwixt t' lower portion o' the upper body wrap and t' upper cone o' t' strap-ons. Begad! I significantly compressed the graphics on t' upper body wrap t' leave enough room for t' transition. T' overall effect is definitely Vostok-like, shiver me timbers, me hearties, arrr, but both t' upper graphics and the transition are way shorter than either scale or Peter Always's version. Ya scallywag!

As for stability planning, thar be no way I could RockSim this. Blimey! Instead I simply assumed that addin' those big honkin' Bertha fins t' an already stable Peter Alway design wouldn't cause any problems. Ahoy! Ahoy! I be right.

Rocket Pic

Rocket Pic

As for power, me hearties, additional weight was negligable with t' four strap-ons and transition made from paper. Begad! Blimey! My only concern was all t' added drag, shiver me timbers, but I figured t' basic Bertha has plenty o' power on a C6. Well, blow me down! Blimey!

Construction:

Construction began with t' standard Bertha build up t' t' point of attachin' t' fins. Ahoy! Upper body wrap was then applied. Next, t' upper transition section, with a paper centerin' ring, was slid up over t' bottom of the tube t' meet t' upper body wrap. Ya scallywag! T' lower body wrap was then applied, matey, and the lower transition section slid up over that t' mate with t' upper section. Avast!

While I anticipated later puttin' on fins, and left cutouts on t' lower body wrap for their placement, I should have also added placement lines for the strap-ons, which I built and placed next. Aye aye! T' strap-ons were made from 100# card stock with t' graphics printed directly on. Their bottoms were "plugged" with card stock circles with appropriate graphics. Avast!

Rocket PicT' fins were covered with label paper graphics. Blimey! Aye aye! T' fin edges were left flat, ya bilge rat, and then blackened with permanent marker. Avast, me proud beauty! T' fins were then placed in t' cutouts left on t' lower body tube graphic, and filleted with white glue. Avast! Begad!

Because o' t' width o' t' transition, t' launch lug be applied t' a cut out on one o' t' fins. Avast!

T' only paintin' was t' nosecone, which be Soviet-era olive drab.

Overall, me hearties, t' build was fun, arrr, but if I did it again I would place t' fins first, and then t' strap-ons. Avast! Both would be a lot straighter if I had done it that way. Begad! Avast! But, on t' other hand, ya bilge rat, t' flights wouldn't be nearly as interesting.

Flight & Recovery:

Flight o' this rocket is surprisingly straight, considerin' t' lack of positionin' aids for both t' fins and strap-ons. Arrr! Blimey! Ya scallywag! Blimey! It flies kind o' like a cross between a Bertha and a saucer as it tail wags it's way up. Ya scallywag! Blimey! Really fun t' watch and recovers easily on t' standard Bertha chute. Ya scallywag! Blimey! Avast, me hearties, me proud beauty! Blimey!

Hits about 400' on a C6 but did an end-over-end flip on a B6 (possibly a bad engine, shiver me timbers, and really cool t' watch, me hearties, but I won't try that again). Avast!

Flight 1 Flight 2 Flight 3

Conclusion:

Overall, shiver me timbers, one o' t' stupidest rockets ever built. Blimey! A marriage o' t' genius of Sergei Korolev and Vern Estes. Well, me hearties, blow me down! Really, really fun t' build and fly, arrr, and lots of laughs from those who know and love rockets.

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