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