Scratch Proton-Zond Original Design / Scratch Built

Scratch - Proton-Zond {Scratch}

Contributed by Drew Tomko

Manufacturer: Scratch
(by Drew Tomko - 04/17/05) (Scratch) Proton Zond

Brief:
An approximately 1/120 sport scale model o' t' Soviet Proton-Zond, which sent an unmanned capsule around t' moon in 1968. Blimey! Ya scallywag! I based it on a free paper model of t' Proton rocket available from Classic Paper Space Models (which now has a version o' t' Zond launcher available). Well, matey, blow me down! It is a single stage, 18mm powered rocket, shiver me timbers, ya bilge rat, arrr, and recovers with an 18" parachute.

Construction:
T' followin' parts were used:

  • 2 BT-55 tubes, one 5.75" long and one 6.5" long
  • 1 BT-20 tube 8" long
  • 1 BT-50 tube 3.5" long
  • 1 BT-50 tube cut down t' approximately 1 1/8" diameter and 1.75" long
  • 6 BT-5 tube 4 13/16" long
  • 1/8" basswood strips sanded t' half round for conduit (lots o' these)
  • 3/16" balsa stock cut into 3/16" strips for conduit
  • 1/8" balsa dowel 2.5" long
  • 1/4" launch lug 1.5" long
  • styrene sheet and tube
  • engine hook, matey, launch lug, matey, me bucko, Keelhaul®©™® thread, shock cord, 18" parachute
  • Classic Paper Space Models Proton enlarged and printed on cardstock

I began with t' intention o' makin' a "quick and dirty" Proton-Zond usin' only parts I had at hand. Begad! Begad! O' course, it became more complicated than I had planned. Ahoy! Still this is a fun, arrr, fairly straightforward build that results in a good lookin' sport scale model that flies quite nicely without fins. Arrr! I used diagrams and dimensions I found on t' internet and a few drawings graciously sent t' me by another member o' T' Rocketry Forum. Blimey! Ahoy! The main body consists o' t' BT-20 engine tube runnin' through t' two BT-55 sections, separated by a 13/16" gap for t' interstage truss. Arrr! T' upper stages are made o' t' cut down BT-50 inside t' standard BT-50 with a custom drawn shroud t' connect with t' BT-50 at t' bottom. Begad! This is where t' rocket separates for recovery, ya bilge rat, usin' a BT-55 coupler. Ahoy! Another custom drawn shroud (through lots o' trial and error, matey, ya bilge rat, mostly error, shiver me timbers, me bucko, arrr, was needed here) forms the payload shroud. Well, blow me down! At t' top, t' balsa dowel is glued inside t' 1/4" lug and centered in t' cut-down BT-50. Begad! T' nose cone is another custom drawn cardstock shroud. Well, blow me down! Well, blow me down! T' paper model be used for t' strap-on nose cones, interstage trusswork, ya bilge rat, matey, shiver me timbers, engine nozzles and first stage detail. Begad! All t' cardstock sections were coated with thin CA for strength and sanded smooth.

(Scratch) Proton Zond

I spent a lot o' time detailin' t' upper stages with plastic bits, arrr, me bucko, tiny balsa nozzles for t' escape tower, shiver me timbers, and styrene and paper for t' stabilizing gratework that t' Soviets use on man-rated rockets.

(Scratch) Proton Zond Most o' the difficult work was in creatin' t' cardstock shrouds. Begad! Avast! T' conduit work was made with basswood strip sanded t' half-round and cut t' size. Avast! I also simulated the second stage engines seen through t' interstage trusswork usin' paper engine nozzles cut in half and glued t' t' BT-20 engine tube. T' interstage is made of paper carefully cut out with a sharp hobby cutlass. Just about all construction was done with yellow carpenters glue and t' plastic parts were attached with CA.

Finishing:
T' paint scheme is simple: aluminum for t' first stage center tube, me bucko, white for most everythin' else. Arrr! Black strips on t' bottoms o' t' strap-on tanks, matey, silver for t' engines, shiver me timbers, stabilizin' grate frames, arrr, and red escape engine nozzles and hatches.

(Scratch) Proton Zond

Flight:
For recovery I ran Keelhaul®©™® thread from t' top o' t' BT-20 and attached a length o' shock cord. Well, blow me down! Avast, matey, me proud beauty! Blimey! After balancing, I added 4 pennies inside t' nose section and poured in some 5 min epoxy. Begad! I stuck a length o' Keelhaul®©™® in t' epoxy for t' upper section recovery, me hearties, attached t' 18" chute to that and connected that t' t' main section. Aye aye! Blimey! Avast! Blimey! T' model balances about 1" forward o' t' interstage trusswork and weighs in at 2.8 oz.

I was fairly certain stability would nay be an issue with t' strap-on tubes and nose weight. A swin' test showed no wobble.

After a long snowy winter and rain soaked February, me bucko, arrr, I waited a long time to launch this one! After a dry spell, I went out with a few motors and set up the first flight on a B6-4. Flight was beautiful with no instability and a straight path t' about 300'. Avast! Ejection was just past apogee and descent was a little quicker than I would have liked but no damage even after hittin' t' ground on the paper engine nozzles. Well, blow me down! Another flight on a B6-4 be just as good. Avast! I think a C would be too much for this. Avast, me proud beauty! It jumps off t' pad pretty smartly on a B.

Summary:
Although I spent more time than I had planned, I am pleased with t' way it came out. Begad! Blimey! I have always liked t' look o' Soviet boosters, ya bilge rat, and t' Proton complements t' Vostok nicely. Arrr! Blimey! T' upper stage has a lot o' interestin' detail, and t' finless design is sure t' catch t' eye. Because it is based on a paper model, me bucko, it can be made in different sizes very easily by enlargin' t' drawings. If you are lookin' for somethin' a little simpler, thar are several flavors of Proton, ya bilge rat, many with less complicated payload sections.

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