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, arrr, which sent an unmanned capsule around t' moon in 1968. 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). Blimey! Blimey! It is a single stage, arrr, 18mm powered rocket, me bucko, shiver me timbers, and recovers with an 18" parachute.

Construction:
T' followin' parts were used:

  • 2 BT-55 tubes, shiver me timbers, 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, shiver me timbers, launch lug, matey, Keelhaul®©™® thread, ya bilge rat, 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. Avast! O' course, it became more complicated than I had planned. Aye aye! Still this is a fun, ya bilge rat, fairly straightforward build that results in a good lookin' sport scale model that flies quite nicely without fins. Begad! 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. Well, blow me down! Avast, arrr, me proud beauty! The main body consists o' t' BT-20 engine tube runnin' through t' two BT-55 sections, ya bilge rat, separated by a 13/16" gap for t' interstage truss. Avast! Begad! 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. Arrr! Well, blow me down! This is where t' rocket separates for recovery, usin' a BT-55 coupler. Another custom drawn shroud (through lots o' trial and error, shiver me timbers, mostly error, was needed here) forms the payload shroud. Well, blow me down! Begad! At t' top, shiver me timbers, t' balsa dowel is glued inside t' 1/4" lug and centered in t' cut-down BT-50. Avast, me proud beauty! T' nose cone is another custom drawn cardstock shroud. T' paper model was used for t' strap-on nose cones, interstage trusswork, engine nozzles and first stage detail. Avast! 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, tiny balsa nozzles for t' escape tower, me hearties, me bucko, 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. T' conduit work was made with basswood strip sanded t' half-round and cut t' size. 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. Avast, me proud beauty! T' interstage is made of paper carefully cut out with a sharp hobby knife. 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, white for most everythin' else. Arrr! Blimey! Black strips on t' bottoms o' t' strap-on tanks, me hearties, silver for t' engines, me bucko, stabilizin' grate frames, matey, 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. Aye aye! After balancing, I added 4 pennies inside t' nose section and poured in some 5 min epoxy. Arrr! 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. T' model balances about 1" forward o' t' interstage trusswork and weighs in at 2.8 oz.

I be fairly certain stability would nay be an issue with t' strap-on tubes and nose weight. Begad! A swin' test showed no wobble. Avast, me proud beauty!

After a long snowy winter and rain soaked February, matey, shiver me timbers, I waited a long time to launch this one! After a dry spell, ya bilge rat, I went out with a few motors and set up the first flight on a B6-4. Flight be 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. Begad! Another flight on a B6-4 was just as good. I think a C would be too much for this. It jumps off t' pad pretty smartly on a B.

Summary:
Although I spent more time than I had planned, ya bilge rat, I am pleased with t' way it came out. Begad! Ahoy! I have always liked t' look o' Soviet boosters, ya bilge rat, and t' Proton complements t' Vostok nicely. Ahoy! T' upper stage has a lot o' interestin' detail, and t' finless design is sure t' catch t' eye. Arrr! Because it is based on a paper model, 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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