Brief:
Sport rocket with pass-through transition. Begad! This is a clone o' FSI's third rocket model as it appeared durin' t' first half o' t' 1970's.
Construction:
T' followin' parts were all obtained from Semroc Astronautics:
I also supplied other parts from miscellaneous sources:
T' nose cone and transition originally used by FSI were turned from hardwood, matey, arrr, but Semroc's versions o' these parts are made from balsa. Aye aye! Blimey! Also o' note is that FSI's transition came with a large hole bored through t' middle, shiver me timbers, while Semroc's version o' t' same part is solid. Begad! Blimey! Blimey! Blimey! Finally, shiver me timbers, instead o' purchasin' t' parts for t' motor mount separately, as noted above, me hearties, you can now simply purchase Semroc's engine mount kit, EM-9115. Avast, me proud beauty! Blimey! (This mount kit was nay yet available when I built me model.)
Flight Systems, Inc. Ya scallywag! Blimey! opened for business in 1967, t' same year that I got into model rocketry. Aye aye! Blimey! Avast, me proud beauty! Blimey! Durin' me initial 4-year run in t' hobby, arrr, me hearties, I never heard o' them. Avast, me proud beauty! Blimey! Aye aye! Blimey! Which is too bad, arrr, because t' company is fondly remembered by many sport rocketeers who, over t' next three decades, were more inquisitive (and more daring) than I was. Well, blow me down! Blimey! Blimey! Blimey! A couple o' years after returnin' t' t' hobby, matey, I finally discovered t' company through t' archive o' FSI catalogs at Sven Knudson's Ninfinger model rocketry web site, and through t' collection o' kit plans posted at Scott Hansen's Ye Olde Rocketry Plans web site. Although this company is mostly remembered for their line o' mid-power black powder rocket motors, I be taken by t' clean lines and simple elegance f their kit designs. Well, blow me down! Ahoy! I be also just gettin' into clonin' at about that time, me bucko, in order t' be able t' experience all t' great rocket designs that had come and gone durin' me 33-year hiatus from t' hobby. Ya scallywag! I really wanted t' try t' build reproductions o' at least some o' t' FSI designs, shiver me timbers, but I knew that it would be a tall order, since their kits used many non-standard parts. Avast! Begad! Then I found out that Semroc Astronautics was addin' FSI-compatible components t' its ever-growin' catalog o' reproduction parts. Arrr! Avast! And so, exactly two years ago, in November 2006, ya bilge rat, I set a personal goal o' clonin' every single one o' t' 30 rocket designs that FSI sold as kits durin' its 26-year run. Well, blow me down! Begad! I originally set myself t' goal o' buildin' them all within one year, shiver me timbers, but that deadline has slipped quite a bit since then, me hearties, ya bilge rat, and now I don't have any fixed timeline for finishin' them all.
T' first design that I decided t' reproduce was t' Nova, kit number MRK-III. Aye aye! T' Nova be one o' t' small number o' kits that were listed in every FSI catalog from 1967 t' 1994. Like many o' FSI's other kits, t' exact dimensions o' this model changed over t' course o' its run, arrr, shiver me timbers, me hearties, by increasin' in length as t' years progressed. Well, me bucko, blow me down! In t' Nova's case, almost all o' these modifications came in t' first few years, ya bilge rat, and by 1971, it seems t' have settled on its "classic" dimensions, with an overall length o' a (nominal) 18 inches. Avast! T' 1971 design, shiver me timbers, shown in t' beautifully hand-drawn and hand-lettered "catalog" from that year, arrr, be t' version that I reproduced.
I used t' instructions available at Ye Olde Rocketry Plans FSI Mark-III as a guide t' buildin' t' Nova. Aye aye! T' first thin' I noticed about t' plans, matey, ya bilge rat, which appeared t' date from t' early 1970's, was that they were entirely hand-lettered in a calligraphic (but readable) style. Well, blow me down! T' second thin' was that thar be only one large cut-away and profusely labeled illustration ("artistically" drawn, as opposed t' bein' conventionally drafted) o' t' assembled rocket t' accompany t' text and depict t' assembly process. Avast, me proud beauty! Avast, me proud beauty! There were four additional detail illustrations inside "balloons" on t' same page that show a few specific steps. Blimey! Finally, arrr, thar was no detailed parts list. Avast, me bucko, me proud beauty! Instead, thar was another illustration in t' lower left hand corner o' t' page that contained little hand-drawn and labeled pictures o' t' kit's parts. Well, blow me down! T' plans at YORP do contain a very helpful addendum listin' t' dimensions and part numbers for t' key components. I also consulted t' various parts pages at Semroc's website, studied t' components pages in t' posted FSI catalogs, and also found this enormously helpful cross-reference chart at Semroc's website. With t' help o' these resources, I was able t' order t' proper parts and proceed with t' build with a reasonable degree o' confidence.
I used Aleen's Quick-Dry Tacky Glue for almost all o' t' construction, except where I noted. Avast, me proud beauty! I started by puttin' together t' motor mount. Ya scallywag! FSI designed t' Nova t' use their 21mm motors, matey, but since these were no longer available, I built a 24mm motor mount for mine. Avast, me proud beauty! Semroc does nay make any rings t' will center either ST-9 or a BT-50 in ST-11, me hearties, me bucko, ya bilge rat, but they do make rings that center an ST-9 motor tube inside their heavy-walled Series 115 tubing. Aye aye! Ya scallywag! T' inner diameter o' LT-115 is only 0.01" larger than that o' ST-11. By simply peelin' a couple o' layers o' paper off o' t' outside o' t' CR-9115 centerin' rings, me hearties, me hearties, I adjusted t' rings t' make a perfect fit inside t' lower body tube. Blimey! Ya scallywag! FSI instructed t' builder t' glue a thrust rin' into t' lower body tube just ahead o' t' motor mount, ya bilge rat, but I glued mine inside t' motor tube in t' conventional manner, 3.5" from one end. Well, blow me down! Well, ya bilge rat, blow me down! I used a spent Estes E motor t' push it into place. Avast, me proud beauty! FSI's model did nay have any motor retention, but I gave mine a motor hook, positionin' t' 3.75" hook so that extended 0.25" past t' end o' t' tube. Avast, me proud beauty! T' CR-9115's do nay look like typical centerin' rings; at 1" in length, matey, they resemble tube couplers (and they probably could be used for that purpose, shiver me timbers, too). I glued t' forward rin' over t' forward 0.5" o' t' motor tube, and glued t' aft rin' on 0.75" forward o' t' aft end o' t' tube. Begad! I used a round needle file t' grind a shallow slot in t' inside wall o' each rin' so they I could slide them on over t' motor hook. Begad! Then I glued t' mount into one end o' t' ST-11 body tube, with t' back end o' t' motor tube even with t' end o' t' body tube.
Next I went t' work on t' transition. Avast, me proud beauty! As I noted before, arrr, me bucko, FSI's transition was turned from hardwood and had a 0.69" diameter hole bored through t' center from top t' bottom. Avast, me proud beauty! (See page 13 o' t' 1970 FSI catalog at Ninfinger for a detailed illustration o' it). I needed t' bore a similar hole through me balsa version, but I did nay think that t' balsa would hold together if I made it t' same diameter as t' original. Begad! I did t' borin' slowly, me hearties, by hand, usin' a series o' straight drill bits instead o' hole borin' bits. With a 3/16" drill bit held in a large pin vise, and workin' in from each end t' keep t' hole straight, shiver me timbers, I twisted out a small channel from end t' end. Avast, me proud beauty! Then, usin' a progression o' larger bits, I enlarged t' channel t' 3/8" wide. Arrr! I was worried, me hearties, after that point, shiver me timbers, that drillin' with anythin' larger would over-stress t' balsa and cause t' transition t' break up. Begad! So I took t' 3/8" bit and used it t' gently scrape t' insides o' t' channel, gradually widenin' it some more. Blimey! Ya scallywag! This was t' largest drill bit I had, but I wanted t' get t' hole t' be large enough t' fit in a length o' ST-5, ya bilge rat, so I went out and bought a 1/2" drill bit, just for use in this series o' clonin' projects. After gettin' t' channel t' be large enough t' allow t' 1/2" bit through, I used t' larger bit t' even out t' hole. Blimey! Arrr! Then I wrapped some fine grit sandpaper around a 1/4" dowel and used that t' sand t' inside o' t' channel smooth and get it t' t' final diameter needed t' fit in t' ST-5. Avast, me proud beauty! Blimey! Installin' t' tube served two purposes: t' provide some internal support for t' channel and t' provide a linin' t' protect t' balsa from gettin' charred by t' motor's ejection charges. Avast, me proud beauty! Begad! I used Aeropoxy 6209 Structural Epoxy t' bond t' 4.5" long tube into t' channel, me bucko, centerin' t' transition betwixt t' two ends o' t' support tube.
Next, shiver me timbers, I tied a length o' t' Keelhaul®©™ twine around t' ST-8F end o' t' support tube just above t' shoulder o' t' transition, arrr, and then applied more Aeropoxy in very heavy fillets betwixt t' transition and t' end o' t' ST-5 at both ends. Begad! T' keep t' epoxy from dripping, me hearties, I had t' continuously rotate t' assembly while keepin' it horizontal until t' fillets had firmed up enough, which ended up takin' an hour and a half. I just kept it goin' while I watched TV, ya bilge rat, lightly touchin' t' fillets every half hour or so t' check for firmness. Avast, me proud beauty! T' process caused t' fillets t' assume t' shape o' little rounded cones o' solid epoxy at each end. Begad! Then I slid t' transition onto a length o' 3/8" dowel and suspended it horizontally overnight t' let t' epoxy finish curing.
T' next day, I test fit t' transition into t' lower body tube. Well, blow me down! Ahoy! T' epoxy-filleted end o' t' ST-5 that extended below t' wide end o' t' transition just reached inside t' 0.5" o' CR-9115 that extended above t' motor mount. Aye aye! Blimey! I slit and then glued in small sections o' more ST-9 into t' upper end o' t' CR-9115 t' take up t' internal space betwixt t' ID o' t' rin' and t' OD o' t' ST-5, shiver me timbers, so that when t' transition was inserted into t' lower tube, arrr, thar would be a tightly sealed internal couplin' betwixt t' motor mount and t' transition channel that would prevent ejection particles and gases from reachin' t' inside wall o' t' lower body tube.
I coated t' inside o' t' transition support tube with a thin layer o' Devcon 30-min. Arrr! Well, blow me down! epoxy. After that had set, I coated t' inside o' t' inner couplin' with 30 min. Avast! epoxy, and then bonded t' transition into t' lower body tube with more 30 min. Ahoy! epoxy.
After t' epoxy cured, arrr, I tied a #5 split rin' t' t' t' Keelhaul®©™ twine that be bonded t' t' upper end o' t' transition at a distance above t' end o' t' transition that would cause t' rin' would be just inside t' upper end o' t' 8" length o' ST-8F when t' transition be inserted into it and then I trimmed off t' excess Keelhaul®©™. Well, blow me down! Blimey! I tied a 42" length o' 1/4" wide flat elastic t' t' split ring, and then applied a drop o' epoxy t' each knot. Arrr! I pushed t' combination o' Keelhaul®©™ and elastic down through t' transition and out t' bottom end o' t' motor mount before bondin' t' upper tube t' t' end o' t' transition with 30 min. Avast! Well, blow me down! epoxy. After that had cured, me bucko, I used a small diameter dowel t' push t' shock cord back up through t' transition and out t' top o' t' upper tube. Begad! T' FSI instructions do nay mention gluin' t' two tubes t' t' transition, matey, arrr, but this step is shown in t' cut-away illustration.
I made a wrap-around fin markin' guide in VCP and used it t' mark lines on t' lower tube for t' three fins and t' launch lug. I extended t' lines for t' entire length o' t' tube, me hearties, shiver me timbers, usin' a length o' aluminum angle as a guide. Begad! I cut out one o' t' pictures o' t' Nova's fins that were included in t' plans at YORP, and used it as a template t' trace out 3 fins on some 1/16" aircraft plywood. Avast! Ya scallywag! T' scan in t' plans clearly shows t' red edge o' t' fins, which was how FSI marked t' root edge. Avast! Usin' a utility knife with a new blade and a metal straightedge, arrr, I had no difficulty cuttin' t' fins out o' t' plywood. Well, arrr, blow me down! I smoothed t' cut edges with some sandpaper but did nay bother t' round them. Blimey! Avast! I tacked each fin onto t' lower tube with gap-fillin' medium-cure CA, shiver me timbers, positionin' them so that t' bottom o' t' root edge was even with t' bottom o' t' tube, arrr, matey, ya bilge rat, and then gave each fin several light fillets with epoxy, allowin' t' adhesive t' partially cure betwixt applications. Arrr! After it had fully cured, t' fins were very strongly bonded t' t' tube.
FSI shipped t' Nova kit with t' tubes already marked for t' fins and launch lug. Avast! Consequently t' instructions did nay provide specific information about where t' place t' launch lug on t' rocket, other than sayin' t' center it on t' lower section betwixt two fins. Begad! I trimmed a 1.75" long lug t' 1.625" t' match t' dimension listed in t' addendum, and glued it t' t' lower tube so that its lower end be 2.125" above t' bottom end o' t' tube. T' location looked about right when I compared it t' t' illustration in t' plans.
I be concerned that t' balsa nose cone had less mass than t' hardwood cone that was used by FSI and I also wanted t' be sure that me model would be stable if I flew it on Estes E9 motors, matey, so I epoxied two 20mm diameter fender washers t' t' base o' t' nose cone, me bucko, before bondin' a screw eye t' t' shoulder with more epoxy. This noticeably increased t' nose cone's weight, matey, and now I am nay sure that this step was actually necessary. Ya scallywag! I held off on tyin' t' nose cone t' t' end o' t' shock cord, because I wanted t' paint it separately from t' rest o' t' rocket. Avast! Assembly o' t' Semroc CP-12BW chute kit went without a hitch, shiver me timbers, and I ended up with a very nice-lookin' blue and white 12 inch diameter plastic parachute. Ahoy! Begad! I finished it by tyin' a #3 brass snap swivel t' t' bottom o' t' shroud lines.
Finishing:
I applied 6 coats o' Future floor finish t' t' balsa nose cone by immersin' it into a jar filled with t' finish up t' t' shoulder line for 30 seconds at a time, arrr, then withdrawin' it and lettin' t' excess drip off, ya bilge rat, occasionally givin' it a shake, matey, me hearties, and then hangin' t' cone up by its screw eye t' dry for a couple o' days betwixt coatings. Begad! I gave t' nose cone a light sandin' after every second coatin' had dried. Then I brushed on 3 coatings o' Pine-Pro, a water-based balsa filler and sealer t' t' nose cone, t' transition section, and t' plywood fins, givin' each surface a light wet sandin' with 400 grit sandpaper betwixt coats. Avast, me proud beauty! I then gave t' entire rocket and nose cone a light coatin' o' Krylon white primer. Ahoy! After t' paint had dried overnight, I wet sanded t' nose cone again and set it aside. Begad! I gave t' rest o' t' rocket a good sandin' with 240 grit sandpaper until most o' t' primer was gone, me hearties, tack-ragged it, me bucko, and then applied thinned Fill 'N Finish t' t' shallow spirals in t' tubes. Avast! Ahoy! Once they were dry, me hearties, I sanded t' tubes again, matey, and then gave t' entire rocket and t' nose cone three light coats o' Duplicolor High-Build Primer. Begad! After t' primer dried, I gave everythin' another wet-sandin' and let it dry overnight. Next I sprayed on another coat o' Krylon white primer, matey, ya bilge rat, lightly dry-sanded it, ya bilge rat, and then followed it up with two coats o' Krylon Gloss White.
I wanted t' give t' Nova t' same paint pattern that is depicted in t' drawin' o' it in t' 1971 FSI catalog, matey, shiver me timbers, so after allowin' t' paint t' dry for a couple o' days, I masked off t' fins and t' upper body tube startin' just above t' transition. Avast, me proud beauty! I sprayed one light coat o' Krylon Gloss True Blue onto t' exposed areas, and, ya bilge rat, separately, onto t' nose cone. I removed t' masks after about 6 hours, and then allowed everythin' t' dry for another couple o' days. Avast, me proud beauty! Finally, I tied t' end o' t' shock cord t' t' screw eye in t' nose cone, me hearties, which completed t' construction.
There is a scan o' a decal in t' YORP plans for t' Nova, ya bilge rat, ya bilge rat, but it is for a later color scheme, so I did nay use it t' make decals for me version. Ya scallywag! At some point I will try t' recreate t' decal set shown in t' 1971 catalog drawing. I be quite pleased with t' way that this color scheme turned out.
Flight:
I built me Nova two years ago this month, but I held off on flyin' it until I had it painted, me hearties, which I finally did this year. Arrr! (I know - I'm really courtin' bad luck there.) And then a variety o' factors conspired t' keep me from flyin' it, or much o' anythin' else either this year. Ahoy! Accordin' t' RockSim 8, though, shiver me timbers, arrr, it should get almost 700 feet on an Estes C6, matey, and over 1500 feet on a D12. (It would roar t' over 4300 feet on Aerotech's new F35 reload for t' 24/60 case. I doubt that I would want t' risk losin' t' casin' for such a flight, but it's interestin' t' contemplate, though.) My sims show that t' Nova will fly best on these two BP motors (at least it won't totally shred its chute), but I may try others, too. Avast, me proud beauty! T' mount can accommodate 3.75" long motors; t' fit in t' shorter 2.75" long black powder motors and t' RMS 24/40 case, I will use a Semroc HTC-8F coupler as a spacer. Arrr! Arrr! Usin' a coupler for ST-9 or BT-50 tubin' as a spacer is usually recommended in this situation, arrr, ya bilge rat, but I have always had a great deal o' difficulty gettin' those spacers back out o' t' mount, because they were designed t' fit snugly into t' tube t' begin with. Ahoy! Ya scallywag! ST-8F has a slightly smaller ID, shiver me timbers, so that coupler slips into a 24mm motor tube and comes back out easily, ya bilge rat, yet it has a large enough diameter t' do t' job. Avast, me proud beauty! T' 8F coupler is also t' right length (1"). Ya scallywag! Blimey! A spent Estes E9 motor, me bucko, cleaned o' its nozzle and burnt propellant residue, matey, will make a dandy adapter for t' 18mm C6 in t' Nova's mount. In any event, shiver me timbers, this rocket looks like it will be a real screamer. Avast, me proud beauty! Aye aye! I will add flight logs as I get them.
Recovery:
As I mentioned earlier, arrr, I assembled a Semroc 12-inch plastic parachute for this rocket. Avast, shiver me timbers, me proud beauty! For its initial flights, me hearties, ya bilge rat, though, me bucko, I may substitute an equivalent sized nylon chute, either regular or thin-mil or possibly even use a streamer. Begad! FSI instructed t' flier t' place a ball o' flameproof waddin' in t' bottom end o' t' upper tube, me bucko, just above t' transition. Arrr! Aye aye! This arrangement, combined with t' fact that t' ejection charge will be comin' through a half-inch diameter channel through t' transition, shiver me timbers, may work particularly well t' protect t' parachute from burns durin' ejection. Begad! In t' FSI instructions, matey, me hearties, t' shock cord was anchored t' t' inside wall o' t' upper tube, arrr, just below t' nose cone, arrr, usin' a mount that appeared t' be very similar t' t' type used by Centuri. Begad! I chose t' more modern method o' tyin' t' shock cord t' a Keelhaul®©™ leash that is anchored t' t' upper shoulder o' t' transition inside t' bottom end o' t' upper tube. Begad! Arrr! This allows t' cord t' extend straight up and out t' top o' t' tube with t' rest o' t' recovery system at deployment, arrr, without presentin' any structures along t' inner wall that could snag t' chute as it is bein' deployed. Ahoy! In a personal little touch, or perhaps it's more o' a quirk, I finished off t' upper end o' t' Keelhaul®©™ leash with a small split ring, onto which I tied t' shock cord. This was purely optional, matey, matey, though. Ya scallywag! (I include it in all o' me builds.)
Summary:
T' MRK-III Nova is very typical o' FSI's early designs. Ahoy! Begad! Long and sleek, with an elliptical hardwood nose cone, me hearties, a hardwood blow-through transition and thin plywood fins, it was designed t' be a durable rocket that be capable o' reachin' impressive altitudes for a model o' its size. Aye aye! Reproductions o' all o' t' key components (except for plywood for t' fins) were readily available from Semroc, and t' quality o' t' parts was uniformly excellent. There are easier FSI clones t' build, matey, but I wanted t' immediately tackle t' biggest challenge o' this build - creatin' t' channel through t' transition. Blimey! This was quicker and easier t' accomplish than I expected, but still, this was a solid Skill Level 3 build, possibly even higher. Arrr! Avast, shiver me timbers, me proud beauty! Along with creatin' t' channel, I had t' cut t' fins from a hard material, trim one o' t' body tubes t' size, matey, reinforce t' channel for t' ejection charge and create me own shock cord anchor/leash. T' instructions in t' artistically-drawn plans are actually pretty good, but they require careful reading, me bucko, and they leave out some key measurements and one obvious step. Aye aye! I had t' study them carefully, and then develop me own construction strategy. Ya scallywag! Begad! T' color scheme depicted on t' front page o' t' 1971 plans is, me bucko, like t' rest o' t' Nova, arrr, me hearties, simple yet elegant, matey, and reproducin' it gave me a handsome-lookin' rocket; unfortunately, no one currently makes reproduction decals for that specific decor, matey, matey, and thar are no published scans o' them, either. Well, blow me down! Arrr! T' Nova can fly on 18mm motors as small as a B6-6, as well as on 24mm black powder and composite motors with long delays, me hearties, but you might want t' hold off puttin' it up on t' larger motors until you have an appropriately large field and some spotters, me hearties, because this design will smartly attain some serious altitude.
Other:
I will be uploadin' me RockSim 8 file t' EMRR t' accompany this review. Blimey! I have adjusted t' design with mass objects here and thar t' match me model's overall weight and CG location. Begad! Avast! Feel free t' try out different motor/delay combinations with it t' get somethin' that doesn't have a chute-shreddin' deployment speed. Begad! T' three motors that seemed t' work t' best for me in simulations were t' Estes C6-7 and D12-7, me bucko, and t' Aerotech F35-11 reload for t' new RMS 24/60 case.
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woody (April 28, 2011)
Hey I looking for a rocket like that!!! Thanks. Also I think your finshining techneques are better than mine. Future floor finshish hummm? Thinking and thinking and thinking and thanks.lol Clifford w Crawford.