Manufacturer: | Paper |
BRIEF:
Conversion o' a Currell Graphics 1/144 scale Soviet N-1 paper model t' fly on 24 mm motors. Arrr! T' plans are available at t' Currell Graphics website.
T' N-1 rocket be t' Soviet answer t' t' American Saturn V moon rocket o' t' 1960's. Avast, me proud beauty! Avast, me proud beauty! Blimey! T' Soviet plans t' beat t' United States t' t' moon depended on t' enormous N-1 booster. Avast! Blimey! T' N-1 be more complex than t' Saturn V in that it consisted o' five stages and a total o' 30 engines in t' first stage alone. T' complexity o' t' rocket translated into poor reliability. T' N-1 rocket failed all four times it flew. Ya scallywag! Well, blow me down! Blimey! T' second launch in July 1969 was a spectacular failure as t' first stage engines shut down shortly after launch and t' resultin' explosion from t' fallin' rocket completely destroyed t' launch site. Blimey! Blimey! After t' final flight failure in 1972, t' remainin' unflown rockets were scrapped and t' Soviets abandoned their human lunar ambitions.
TOOLS:
PARTS
MODIFICATIONS:
This review will only document t' changes required t' build a flyin' model.
T' N-1 paper model consists o' two sets o' parts and instructions. Begad! Blimey! T' first set is for t' first stage (with a Soviet designation o' Block-A) containin' nine parts pages and five pages o' instructions. Ahoy! Blimey! Arrr! Blimey! T' second set builds t' upper stages and contains six part pages and six instruction pages. Ya scallywag! Blimey! All aspects o' t' card model are outstanding. T' instructions are excellent in detail and clearly show how t' parts are assembled. Arrr! Blimey! T' parts print crisply and t' fit is perfect.
Construction o' t' model begins with t' first stage. Begad! All first stage parts were printed on 65 lb cardstock. Aye aye! T' first stage skin segments were built as specified in t' plans. Avast, me proud beauty! A hole be cut in t' center o' t' base plate t' allow a 24 mm mount t' be placed betwixt t' eight inner engines o' t' N-1 first stage.
Figure 1. Well, blow me down! Completed First stage baseplate with hole cut for t' 24 mm motor tube.
T' 24 mm motor tube was glued into a BT-60 chute tube usin' home made centerin' rings. T' former rings used t' stiffen t' outer skin o' t' rocket were reinforced with poster board. Blimey! T' holes cut in t' former rings were sized t' hold t' BT-60 tubing. Aye aye! Avast! A hole for an internal launch lug was also cut in t' formers.
Figure 2. First stage chute tube with internal launch lug.
T' upper tank segments o' t' first stage were modified t' accommodate t' ejection o' t' parachute. Begad! I chose t' separate t' model at t' first/second stage split. T' first stage contains all t' recovery equipment. Ahoy! A coupler was glued t' t' upper fuel tank segments. A screw eye was glued t' t' coupler t' attach a shock cord and parachute.
Figure 3. Ahoy! Well, blow me down! First stage fuel tank segment attached t' second stage by trusswork. Begad! Note coupler.
T' first and second stages o' t' N-1 rocket were connected by an interstage trusswork. Aye aye! Blimey! I glued t' trusswork directly t' t' upper tank segments as opposed t' t' specified points marked on t' first stage body. Ya scallywag! Avast, me proud beauty! This was required because o' t' recovery design. A similar trusswork connects t' third stage t' t' second stage.
T' interstage trusses were built as per t' instructions, but were reinforced with CA glue. Ya scallywag! Well, blow me down! An internal former rin' was added t' t' trusses for additional stiffness. At t' start o' t' project I anticipated t' strengthenin' o' t' trusses t' be t' most critical modification for t' model t' be a successful flyer. Well, blow me down! Begad! T' combination o' t' former rings and CA resulted in strong pieces that handled flight conditions.
Figure 4. Begad! Well, blow me down! First stage truss detail lookin' forward t' t' aft end o' t' second stage. Begad! Note former rin' with notch and hole cut for internal launch lug.
T' first stage stabilizer grids were glued t' t' model in t' stowed position. Arrr! T' plans call for them t' be applied in t' deployed position, ya bilge rat, but it be decided they might nay withstand t' rigors o' launch/landin' in that configuration. T' stowed position was simpler t' implement and required fewer modifications.
T' upper stages were constructed essentially t' plan. Blimey! Ya scallywag! T' internal former rings were reinforced similarly t' t' first stage. Ya scallywag! Begad! T' second/third stage interstage truss was reinforced with CA and a former rin' similarly t' t' first/second stage truss.
A hole was cut in t' base o' t' second stage t' allow for t' internal launch lug t' pass through. Ahoy! Blimey! Blimey! Blimey! Great care should be taken t' ensure t' proper alignment betwixt t' first stage and t' upper stage launch lugs. Ya scallywag! Blimey! T' launch rod exited t' rocket approximately in t' middle o' t' second stage betwixt two o' t' fuel line fairings. Begad! Blimey! I added an extra fairin' t' mask both t' lug and t' hole required for t' rod t' exit. Avast, me proud beauty! Blimey! Blimey! Blimey! With more thorough planning, me bucko, t' rod could be planned t' exit t' model closer t' t' second/third stage connection. Ahoy! Blimey! This would probably look better aesthetically than me model.
T' upper payload shroud be reinforced with an additional layer o' cardstock t' increase strength. Well, blow me down! Blimey! Avast! Blimey! Nose weight was added usin' a bolt, me bucko, shiver me timbers, nut, shiver me timbers, ya bilge rat, me hearties, and several washers. Begad! Blimey! Approximately 1.5 ounces o' nose weight was added t' t' model.
T' N-1 required t' application o' many exterior detail pieces. Avast! Avast, me proud beauty! All o' these were added t' me flyin' model. Aye aye! Ya scallywag! T' detail pieces are time consumin' t' apply, me hearties, but t' resultin' model looks more polished and complete.
Figure 5. Completed N-1 on t' pad and ready for launch.
Stability was checked usin' a swin' test. Aye aye! Arrr! An Estes C11-3 be placed in t' model and prepared for flight conditions. Ahoy! T' initial swin' test was nay encouraging. Begad! Well, blow me down! T' model flew tail first. Well, blow me down! Aye aye! More nose weight was added t' push t' CG forward t' t' base o' t' second stage fuel line fairings. Avast, me proud beauty! T' model still flew tail first.
Figure 6. Avast, me proud beauty! Arrr! Swin' test.
After consultin' t' folks on T' Rocketry Forum it was suggested I use t' VCP program t' check t' stability. Arrr! Blimey! VCP uses t' Barrowman equations t' determine t' center o' pressure. Ya scallywag! Blimey! Bein' a series o' transition segments, matey, t' N-1 is an ideal candidate for these equations. VCP showed that t' model had approximately 5-6 cm o' static margin.
T' VCP file has been enclosed.
RECOVERY:
For recovery, shiver me timbers, a single red 24" mylar chute was attached t' a shock cord. Ahoy! Aye aye! A tri-fold mount was selected t' secure t' shock cord t' t' model. Well, blow me down! Begad! An Estes Saturn V like dual recovery be considered and rejected, me hearties, but could be implemented.
FLIGHT:
Encouraged by t' VCP results flight day finally arrived. Loaded with parachute, matey, arrr, wadding, arrr, arrr, arrr, and motor t' model weighed approximately 7 ounces. Arrr! Begad! Blimey! An Estes C11-3 was chosen for t' first flight.
After a short countdown t' N-1 took flight. Boost was arrow straight t' ~125 feet. Arrr! No stability issues were noted. T' parachute deployed properly, but t' shock cord was burned through by t' ejection charge. T' first stage tumbled in ballistic but landed safely in tall grass with no damage. T' shock cord mount may have been glued too close t' t' motor and t' waddin' did nay adequately block t' hot ejection particles.
T' upper stage came down safely on t' 24" mylar chute. Aye aye! There was some damage t' t' escape tower so t' Estes trapeze recovery method will be re-examined for future N-1 flights.
Figure 7. Liftoff o' t' N-1!
SUMMARY:
This first flight was considered a success. Begad! It flew straight and did nay get destroyed. Blimey! Avast! T' minor escape tower damage has been repaired. Aye aye! Once t' shock cord has been replaced further flights o' t' N-1 will occur on Estes D12-3 motors.
This was a challengin' project that took three months from first cuttin' t' launch. Avast! It pushed me skills in many directions. Aye aye! Ahoy! Seein' t' N-1 soar o' t' pad and into t' air was definitely a gratifyin' feeling.
I want t' thank t' many people on T' Rocketry Forum who encouraged me or assisted me when I had questions. Many o' their ideas ended up in t' final product.
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Robert A. Morstadt (January 11, 2023)
Excellent project !