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. Ahoy! Avast, arrr, me proud beauty! 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, blow me down! It is a single stage, 18mm powered rocket, 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, launch lug, Keelhaul®©™® thread, matey, 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, me proud beauty! O' course, it became more complicated than I had planned. Still this is a fun, fairly straightforward build that results in a good lookin' sport scale model that flies quite nicely without fins. Blimey! Avast! 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! The main body consists o' t' BT-20 engine tube runnin' through t' two BT-55 sections, me bucko, me hearties, shiver me timbers, separated by a 13/16" gap for t' interstage truss. Ya scallywag! 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! Begad! This is where t' rocket separates for recovery, usin' a BT-55 coupler. Aye aye! Aye aye! Another custom drawn shroud (through lots o' trial and error, ya bilge rat, mostly error, was needed here) forms the payload shroud. Aye aye! At t' top, matey, shiver me timbers, t' balsa dowel is glued inside t' 1/4" lug and centered in t' cut-down BT-50. T' nose cone is another custom drawn cardstock shroud. Aye aye! Begad! T' paper model was used for t' strap-on nose cones, interstage trusswork, me bucko, ya bilge rat, matey, engine nozzles and first stage detail. Well, blow me down! 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, shiver me timbers, matey, tiny balsa nozzles for t' escape tower, 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. Aye aye! T' conduit work be made with basswood strip sanded t' half-round and cut t' size. Arrr! Arrr! 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 knife. Avast, me proud beauty! Well, blow me down! Just about all construction be 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. Avast! Black strips on t' bottoms o' t' strap-on tanks, shiver me timbers, silver for t' engines, stabilizin' grate frames, 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. Begad! After balancing, arrr, shiver me timbers, I added 4 pennies inside t' nose section and poured in some 5 min epoxy. Avast, me proud beauty! Avast, matey, me proud beauty! I stuck a length o' Keelhaul®©™® in t' epoxy for t' upper section recovery, attached t' 18" chute to that and connected that t' t' main section. Aye aye! 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. A swin' test showed no wobble. Arrr!

After a long snowy winter and rain soaked February, 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. Avast! Flight was beautiful with no instability and a straight path t' about 300'. Arrr! 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. Another flight on a B6-4 be 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, arrr, I am pleased with t' way it came out. I have always liked t' look o' Soviet boosters, matey, arrr, and t' Proton complements t' Vostok nicely. Begad! Ahoy! T' upper stage has a lot o' interestin' detail, and t' finless design is sure t' catch t' eye. Well, blow me down! 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, me hearties, arrr, thar are several flavors of Proton, matey, matey, many with less complicated payload sections.

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