Brief:
Always a nice rocket t' build be t' V2. Avast! For mine I wanted t' use 6" tubin' so I could build it around two 6"x19" Scotglas nose cones. (T' boat tail is a nose cone with t' top missing.) My aim was t' build a V2 capable o' takin' an L motor and dual deployment. Aye aye!

Construction:
T' parts list:

• 2 19" V2 style Scotglas nose cones (1 for boat tail and 1 for nose cone)
• 4 Aluminum Honeycomb fins
• 1 21" x 6" PML phenolic tube for t' airframe
• 1 5" x 6" PML coupler tube for t' electronics bay
• 1 6" x 75mm coupler centerin' rin' (to fit inside boat tail)
• 1 4" x 75mm centerin' ring
• 1 3" bulkhead (for recovery attachment inside nosecone)
• 2 6" bulkheads (for electronics bay)
• 2 29mm x 2" tubes (for recessed ejection charge housing)
• 1 54mm x 4" tube (for recessed recovery attachment)
• 1 54mm x 1.5" coupler tube (end cap t' 54mm x 4" tube)
• 2 5" long threaded rod (through electronics bay)
• 1 18" x 75mm phenolic motor tube
• 4 8mm thick eyebolts for recovery attachment
• 1 U-bolt for recovery attachment
• 1 Aero Pack 75mm motor retainer
• 4 3mm x 10mm headless bolts (to act as reinforcement pins)
• various nuts and washers
• 5 pounds lead shot for nose weight
• Fiberglass and CarbonFibre cloth t' lay-up phenolic airframe
• enough 2-part foam t' fill t' boat tail section
• 10mm thick wooden edgin' t' make alloy fin edges
• 2 25' x 24mm tubular nylon.
• House-Of-Color primer, white and black paint

I designed t' V2 t' recover accordin' t' t' standard 3 piece recovery model (Nosecone, Airframe, Boat tail). Peter Alway's ROTW was essential in gettin' t' specific measurements t' scale. Once all t' measurements were done I entered t' data into RockSim t' establish a set o' components from which the V2 would be built. It smartly became clear that space in t' aft recovery bay would be limited since t' boat tail shoulder protrudes 4" into t' bay. Plus t' L800 motor casin' protrudes a further inch into t' bay. Begad! Blimey! Begad! Blimey! A quick measurement o' me electronics requirements (namely t' height o' t' PCBs plus room for t' wiring) and I had t' minimum height o' me electronics bay to provide t' maximum amount o' room in t' aft recovery section. Ahoy! Blimey! T' further increase t' amount o' available space in t' aft compartment, me hearties, matey, t' ejection charges would be recessed into t' electronics bay. Avast! Blimey! Plus t' recovery harness attachment point t' t' airframe section would also be recessed usin' a 54mm tube that ran through t' center o' t' electronics bay t' allow t' 8mm eyebolt t' be attached t' t' underside o' t' forward bulkplate o' the electronics bay. Well, blow me down! Blimey! Thus t' aft recovery harness would run through 54mm tube (and through t' center o' t' electronics bay) down t' t' eyebolts on t' boat tail. Usin' this method o' hide and seek with t' ejection charges and recovery eyebolt, I be left with a 2" x 6" space t' house me aft recovery harness.

T' build was nay easy nor was it hard. It was complex owin' t' the requirement t' maximize recovery compartment space and support for 75mm motors.

For t' 4 distinctive V2 fins I used 10mm aluminum honeycomb which I was able t' cut t' size with a hacksaw after drawin' t' fin shape on t' material usin' a paper cutout as a template. Ahoy! T' honeycomb cuts easily but resists the blade enough t' make this difficult. Blimey! Once cut t' honeycomb requires the visible edges t' be profiled usin' some other material which can be glued along the edges o' t' fins, shiver me timbers, ya bilge rat, filled and sanded t' provide a finished fin. I used 10mm wood edgin' from me local DIY store. Ya scallywag! Imagine a 1/2 cylinder shape, me hearties, arrr, i.e., one flat side and a dome. Avast, me proud beauty! This worked well t' give a rounded edge on all sides except for t' root edge. Begad! Ahoy! Any gaps betwixt t' honeycomb and t' wood edging were filled with epoxy and later sanded smooth. I have used honeycomb a couple of times now and feel that although it does nay save much build time because of required edgin' and filling, it more than makes up for this by givin' the lightest and strongest fins you will ever make. Truly remarkable stuff.

T' V2 has a boat tail which was created for me build usin' a second fiberglass nosecone identical t' t' first with t' tip cut off. As I was going to be flyin' this on a 75mm motor, matey, I needed t' openin' at t' bottom t' be at least 75mm t' fit t' motor tube. This width was further increased by t' need to house an Aero Pack 75mm motor retainer, shiver me timbers, which be t' one where you have threaded inserts t' drill into your aft centerin' ring. Begad! Arrr! With this in mind, it became clear that t' width would need t' be 4" t' allow for a 4" x 75mm centerin' rin' t' be used t' mount t' motor retainer.

T' point on t' nosecone t' cut was established by placin' t' 4" centerin' rin' inside t' 'clear' nosecone (I did nay have t' aft nosecone gel coated) and then markin' t' position at t' bottom o' t' rin' as it rested in the tip o' t' nosecone. Begad! Blimey!

Once cut, t' boat tail needed slots t' pass t' 10mm wide fin tabs to allow mountin' t' t' motor tube. I used me trusty Dremel t' carefully cut the slots leavin' a 1/2" area at t' bottom o' t' boat tail.

T' aft centerin' rin' was carefully drilled t' hold t' threaded inserts for t' Aero Pack motor retainer. Avast! Blimey! Once drilled, t' inserts were glued into place. Blimey! You want t' avoid gettin' epoxy on t' inside threads so use tape, ya bilge rat, blue tack, shiver me timbers, grease, etc. in or over t' threads. Begad! T' centerin' rin' was then glued into place at t' bottom o' t' boat tail along with t' 75mm motor mount.

T' 4 fins were epoxied t' t' motor tube. T' reinforce t' bond with the motor mount, ya bilge rat, an internal fin-to-fin layup o' carbon fibre was performed between the 4 fins, which be very tricky t' do this as thar be very little room.

I decided t' foam t' remainin' space inside t' boat tail. This would really seal t' fins and motor mount t' t' boat tail. Well, blow me down! Blimey! T' usual 2-part expandin' foam was used for this. Avast, me proud beauty! Blimey! I had also decided t' use t' length o' the boat tail t' house t' antenna t' me Marshal radio transmitter so a plastic tube be inserted into t' boat tail with t' aim o' pourin' t' foam round the tube t' leave a nice channel for t' antenna t' run t' length o' t' boat tail. Begad! Blimey! Arrr! Blimey! However, shiver me timbers, durin' t' pour I discovered that t' foam was eatin' the plastic tube and as a result t' tube was unusable. Ya scallywag! Blimey! Ahoy! Blimey! Fortunately, me hearties, once t' foam set I was able t' use a long hollow brass tube t' "drill" out a channel that ran from t' top t' t' bottom o' t' boat tail. Avast! Blimey! I then placed a new plastic tube down this channel t' house t' antenna.

T' centerin' rin' at t' top o' t' boat tail needed t' fit inside the shoulder. Ya scallywag! Blimey! Hence a 6"x75mm coupler centerin' rin' be custom made for me by Rebel Rocketry. Ahoy! Avast! Blimey! Two 8mm holes were drilled t' hold t' large eyebolts which were epoxied in place with appropriate washers and nuts on t' underside. Additionally, ya bilge rat, matey, shiver me timbers, I drilled a 1/2" hole centered over t' plastic tube (antenna channel) t' fit t' body o' t' Marshal radio transmitter. Ya scallywag! Blimey! The transmitter would be recessed into t' centerin' rin' and boat tail. Ya scallywag! Arrr! Blimey! (I used a 18mm tube with t' end sealed but with a hole for t' antenna t' act as a housin' for t' transmitter.) T' centerin' rin' be epoxied in place with the motor tube protrudin' 1/8" or so above t' top o' t' centerin' ring. Epoxy was applied round t' top o' t' motor tube where it touched the centerin' rin' t' give a solid bond. Thickened epoxy was used t' fill any gaps between t' centerin' rin' and t' boat tail. Well, blow me down! Begad! Blimey! Once dried, me hearties, arrr, I drilled four 3mm holes t' allow 10mm long headless bolts t' pin t' centerin' rin' t' t' boat tail. This would prevent any slippage or other movement due t' t' recovery stresses on t' boat tail centerin' ring.

Fin fillets were applied usin' thickened West Systems epoxy. An interesting affect be observed when applyin' t' fillets. T' resin reacted t' t' 2-part foam in t' cracks betwixt t' fin wall and t' boat tail causin' large bubbles to form--not many o' them but they were big! There was nothin' t' do for this except wait until t' resin cured and then file down t' raised fillet and fill the exposed holes. Begad! Begad! This was a real pain but with some patience all be well in the end.

T' airframe section be a single 20" piece o' phenolic tubing. Ahoy! Begad! Since most o' t' length o' t' airframe would have a double thickness (owin' t' the shoulders o' t' nose cone, shiver me timbers, me bucko, boat tail, me hearties, and t' electronics bay), I decided upon a single layup o' 200g carbon fibre cloth and fiberglass as reinforcement. Begad! I used me trusty Foodsaver t' vacuum bag t' part with couplers inside t' keep the vacuum from crushin' t' tube. Arrr! Avast! End caps were just coupler and normal bulkplates. Ahoy! Easy peasy.

T' electronics bay was more involved than complicated. Since this bay was goin' t' be epoxied t' t' inside o' t' airframe, arrr, I used bulkheads instead of coupler bulkheads. Ya scallywag! T' aft bulkhead was drilled with a central 54mm hole and two opposite 29mm holes. Ahoy! Additionally, two holes were drilled t' allow blind T-nuts t' be attached t' t' underside o' t' bulkhead t' hold two short pieces of threaded rod which would connect t' forward with t' aft bulkheads and provide for strong recovery mount points as well as seal t' bay from the ejection charge gasses. Begad! Once t' 29 and 54mm holes were drilled, matey, t' short (1.5") pieces o' 29mm tubin' were fit and epoxied into their holes with the tubes protrudin' into t' electronics bay, ya bilge rat, along with a longer 54mm tube, which ran t' full length o' t' electronics bay. T' forward bay bulkhead required holes t' be drilled t' allow t' threaded rods t' protrude above the bay and enable win' nuts t' be used. Additional holes were drilled t' enable the forward bulkhead t' use a U-bolt t' attach t' forward recovery harness as well as an 8mm eyebolt t' t' underside o' t' bulkhead centered over t' 54mm opening. Ahoy! Finally, a 1.5" section o' 54mm coupler was attached t' the forward bulkhead centered over t' 54mm tube and eyebolt and pointin' down into the electronics bay as an inside sleeve t' t' 54mm tube. This be finished with some instant heat gasket around t' outside o' t' sleeve tube t' provide a gas proof seal. Begad! Well, blow me down! T' result o' all o' this was t' allow for t' ejection charges t' be recessed into t' electronics bay and t' enable t' aft recovery hard point t' be out o' t' way o' t' L motor plus providin' a little be extra room for t' aft recovery harness.

T' nose cone required a bulkhead t' mount t' recovery harness eyebolt and enough lead shot t' brin' t' center o' gravity forward. Ya scallywag! This turned out t' be 4.5lbs mixed with West Systems epoxy and poured into t' nosecone. Blimey! I used a long 8mm eyebolt with an extra nut and washer t' enable t' resin and lead mixture t' really grip t' eyebolt/bulkhead assembly. Once poured, matey, t' nose cone be suspended in water t' cool t' resin and prevent deformation o' the nosecone as t' exothermic reaction is quite fierce. Begad! Once cured t' nose cone was ready.

Finishing:
Originally I wanted t' use t' camouflage color scheme for t' V2 but I did not manage t' get t' colors sorted for me sprayer. Avast! I decided upon t' black and white roll pattern instead. Well, blow me down! All paints were House o' Kolor brand auto paints. Prior t' painting, I first applied UV Smooth Prime t' t' composite airframe section. Begad! This filled t' weave left by t' fabric. After sandin' with me palm sander, me hearties, it left a nice smooth surface ready for priming. I sanded all flat surfaces usin' me palm sander.

T' primer sprays on bright green and really sticks t' composite surfaces. I put down about 4 coats o' primer before sprayin' t' entire rocket black. Well, blow me down! Blimey! A top coat was applied before bein' left t' dry. Aye aye! Blimey!

I purchased some transparent frisk from an artist supply company. Avast! Arrr! This stuff is great for maskin' as it is very low tack but so thin that you can cut it in place and comes up very easily. Ya scallywag! T' painted edges look very sharp.

Once masked (and this took a couple o' hours t' do), matey, arrr, I sprayed white to finish t' roll pattern. Begad! Begad! T' frisk be removed then a final top coat o' gloss sprayed.

It was a lot o' work in t' end but t' results looked good. I would still like t' use t' camo colors at some point.

No decals were used apart from a small white vinyl East Anglia Rocketry Society (EARS) logo.

Flight:
T' prep for t' first flight consisted o' two 25ft sections o' 24mm tubular nylon, a SkyAngle 44" chute (a bit small for this rocket but I wanted to brin' it down fast), me hearties, and 4 shear pins t' keep t' nosecone on at apogee.

T' electronics consisted o' 1 MiniAlt, arrr, arrr, 1 RDAS, and 1 BlackSky timer. Avast, me proud beauty! The timer would be used t' control an ARRD which would be used as a backup in the event that t' shear pins did nay hold t' nosecone. T' ARRD was attached to the forward bulkhead by usin' one o' t' threaded rods t' act as a threaded post for t' ARRD, me bucko, me bucko, which has a 6mm threaded hole.

T' launch pictures were taken by Nial Oswald. Begad!

T' RDAS and MiniAlt controlled t' primary and backup drogue and main ejection charges (2 x 1gm aft and 2 x 4gm forward). Aye aye! I did nay install any switches so twistin' bare wires wrapped with electrical tape be used t' arm the electronics. Avast, me proud beauty! Aye aye! T' timer requires a screwdriver t' arm it, so I drilled a hole pattern t' allow external armin' and viewin' o' t' LEDs.

T' recovery harness just fit in t' aft section with no drogue chute. Ya scallywag! The nosecone had ample space t' hold t' forward recovery harness and chute.

First flight was on a Cesaroni Pro75 L800 PU classic reload usin' a 75mm Aerotech motor casing. Aye aye! T' reload was a snap t' build and before long I was ready t' go t' t' pad. Well, blow me down!

A quick 5 count, shiver me timbers, ya bilge rat, me hearties, a pause for t' motor came up t' pressure, me hearties, and t' rocket blasted off t' pad. Avast! T' lift off be a very satisfyin' roar with sustained thrust t' push t' 25lb rocket smartly t' 8700 feet but nay too fast t' miss seein' t' rocket climb. Well, blow me down! T' flame plume was as long as t' rocket and looked great.

Recovery:
T' flight on t' L800 was very nice in t' early evenin' sunshine. Ahoy! At apogee, the rocket was out o' sight but a few seconds later you could see a bright orange and yellow chute. Begad! Rats! T' chute deployed at apogee despite t' shear pins and ARRD. Avast, me proud beauty! It was came down fast on t' relatively small chute and landed about 1/2 mile down range in t' crops. Arrr! Initial estimates o' where exactly it landed were short o' its final restin' place. Blimey! Blimey! T' signal on t' tracking receiver be quite weak but enough t' gain a direction. After about 300 meters, it started beepin' louder and a short time later I was standin' over t' rocket in t' crops. Arrr! Avast, me proud beauty! T' two altimeters where beepin' out altitudes over 8700 feet. Upon inspection t' quick descent slightly damaged one o' t' alloy composite fins. Arrr! Nay enough t' cause concern but it may need a bit o' attention before its next launch.

My best guess on t' failure t' retain t' nosecone is:

1. Too much BP be used in appogee ejection charge causin' a violent separation which resulted in t' shear pins -- shearing. This force be also too much for t' ARRD t' cope with so out came t' main chute.
2. T' shear pins were tool small.

Summary:
Great fun in all. Begad! A bit more care on t' amount o' BP with bigger shear pins next time.