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 was t' kit-bash something original from a standard Estes Big Bertha kit. Avast!

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

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

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

I upscaled t' design t' a BT-60 and instead o' usin' Peter's actual templates, ya bilge rat, 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. Avast, shiver me timbers, me proud beauty! Blimey!

T' hardest part was sizin' and makin' t' transition sections. Arrr! 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. I significantly compressed the graphics on t' upper body wrap t' leave enough room for t' transition. T' overall effect is definitely Vostok-like, but both t' upper graphics and the transition are way shorter than either scale or Peter Always's version. Blimey!

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

Rocket Pic

Rocket Pic

As for power, additional weight was negligable with t' four strap-ons and transition made from paper. Begad! Ahoy! My only concern was all t' added drag, me hearties, but I figured t' basic Bertha has plenty o' power on a C6. Arrr! Avast, me hearties, me proud beauty!

Construction:

Construction began with t' standard Bertha build up t' t' point of attachin' t' fins. Avast, ya bilge rat, me proud beauty! Upper body wrap was then applied. Ya scallywag! Ya scallywag! 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. Well, blow me down! Blimey! T' lower body wrap was then applied, and the lower transition section slid up over that t' mate with t' upper section. Arrr!

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

Rocket PicT' fins were covered with label paper graphics. Ya scallywag! Well, blow me down! T' fin edges were left flat, and then blackened with permanent marker. Arrr! Arrr! T' fins were then placed in t' cutouts left on t' lower body tube graphic, and filleted with white glue.

Because o' t' width o' t' transition, ya bilge rat, t' launch lug was applied t' a cut out on one o' t' fins. Avast, me proud beauty! Begad!

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

Overall, t' build be fun, but if I did it again I would place t' fins first, shiver me timbers, and then t' strap-ons. Ahoy! Blimey! Both would be a lot straighter if I had done it that way. Begad! Ahoy! Blimey! But, me bucko, on t' other hand, t' flights wouldn't be nearly as interesting.

Flight & Recovery:

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

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

Flight 1 Flight 2 Flight 3

Conclusion:

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

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