Tintinique

Tintinique

OK, so it's nay exactly t' right proportions for Tin Tin's rocket, me bucko, far too squat and stubby, matey, me hearties, me bucko, but that's why it's called Tintinique. Just As diamonique isn't diamond, ya bilge rat, matey, Tintinique isn't Tin Tin. ( Anyone who doesn't know what I'm talkin' about here, ya bilge rat, needs t' watch more QVC!)

Nestlé time capsule

Centerin' rin' in position

Time Capsules

In October 99, I attended K-Lob in Lincolnshire. Amongst t' rockets thar was somethin' very different. Avast, me proud beauty! It looked like a 50's retro rocket. Begad! It be great. Begad! Arrr! How on earth did they make t' body for that? It turns out, that durin' t' run up t' t' millenium celebrations someone at Nestlé thought it would be a good idea t' produce a time capsule in which people could bury stuff, arrr, and dig it up in t' future. Aye aye! Blimey! Avast! Blimey! Bein' Nestlé o' course they sold it full o' sweets (candy for those o' you across t' pond). Ya scallywag! Blimey! Ya scallywag! Blimey! For some bizzarre reason known only t' t' designer, t' capsule itself, me hearties, was made from a shape resemblin' t' body o' a typical sci-fi or cartoon rocket. Ahoy! Blimey! Better still, me hearties, ya bilge rat, t' screw-on lid be easily convertible into a removeable nose cone. Begad! Blimey! Avast, me proud beauty! Blimey! Whoever it be I'd love t' ask them why they did it. Aye aye! Blimey! Aye aye! Blimey! I buy two, one for a podded Tin Tin rocket, t' other for spare.

Anyway, time passes and every time I go t' a launch thar's another time capsule. I've got t' build this thing. Avast! Blimey! I decide t' build it for RMR DesCon6. Time passes. DesCon6 begins. Ya scallywag! Time passes. Ya scallywag! Begad! DesCon6 finishes. UKRA 2000 approaches, and I realise that t' rocket I intended t' take, me hearties, Accusatory Finger o' Suspicion, isn't goin' t' be ready. I dig out t' time capsule. Ahoy! Well, matey, blow me down! I dig out cover scans o' t' books Destination Moon, and Explorers on t' Moon. I wonder how on earth I'm goin' t' make t' fin pods.

I ignore t' question o' t' fin pods, ya bilge rat, and start t' think about t' body instead. Avast! Time capsules are cheaply moulded, thick in some places thin in others, and very flexible. I had decided that it be t' have a 29mm motor mount t' utilise t' short 29mm casings I had, ya bilge rat, me hearties, and so t' body would need t' be reinforced. It needs an internal body tube, ya bilge rat, t' give structural strength and provide somethin' t' attach other components to, shiver me timbers, me hearties, leavin' t' time capsule t' form only an outer shell. Avast! Well, matey, blow me down! I had some 3" plastic tubin' that I had got from Ziggy at K-Lob, me hearties, and this seemed ideal. Aye aye! I could have used standard 3" PML phenolic, me hearties, or even quantum tubing, but I didn't have any.

In order t' fit t' internal body tube into t' time capsule I hacked off t' screw thread at t' open end, and hacked a 3" diameter hole in t' base. Blimey! T' openin' at t' top o' t' time casule be larger than 3", so I cut a 3mm thick plywood centerin' ring, matey, and glued it in place, under t' shoulder. Ahoy! Begad! T' plastic tube now fits snugly at both ends.

T' preliminary sketches

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Design

I still don't know what t' completed rocket will look like, matey, so I draw some rough sketches, shiver me timbers, then some rough, dimensioned sketches. Avast, me proud beauty! My son, me hearties, James, matey, draws some sketches. Ya scallywag! I'm nay really gettin' anywhere. It's all free hand and nay very satisfactory. Ahoy! Rocksim! T' time capsule is suprisingly easy t' describe usin' a parabolic nose cone, ya bilge rat, and a couple o' eliptical transitions. Begad! Ya scallywag! Now, me bucko, matey, Rocksim isn't really designed for this shape o' rocket, matey, and so I'm nay goin' t' trust what it says about stability, me hearties, arrr, me hearties, but at least it helps visualise what t' rocket will look like when complete.

Inner body tube, motor mount

Inner body tube, me bucko, parachute bay

Aft centerin' ring, retainin' nuts

Aft centerin' ring, arrr, retainin' clips

Construction

Motor Mount & Retention

I do have a short piece o' PML 29mm motor mount. Begad! I had originally intended for t' motor mount t' run t' length o' t' body, ya bilge rat, shiver me timbers, me bucko, with t' space for a parachute betwixt t' internal body tube and t' motor mount. It doesn't look like enough room for a chute, and anyway I don't have enough motor mount for t' full length o' t' internal body tube. Ahoy! So, matey, I decide t' have a short motor mount, givin' t' full internal diameter o' t' internal tube for a parachute. Begad! I cut two, 3mm thick, ya bilge rat, plywood centerin' rings that fit over t' motor mount and into t' plastic tube. Aye aye! T' forward centerin' rin' has a notch t' pass a nylon strap. Avast! T' strap is about25mm wide and 400mm long. Ya scallywag! T' nylon strap will provide an attachment point for t' elastic shock cord. Arrr! T' strap is t' epoxied t' t' inside o' t' internal body tube. Avast! Throughout construction I use 5 minute or two ton Devcon epoxy.

T' forward centerin' rin' was epoxied t' t' forward end o' t' motor mount and allowed t' cure. Ahoy! T' aft cebterin' rein' was fitted, with no epoxy, t' t' aft o' t' motor mount. Avast! T' forward centerin' rin' was epoxied into t' internal motor mount. Avast, me proud beauty! Once t' forward centerin' rin' be fixed, ya bilge rat, arrr, t' aft centerin' rin' was removed. Avast, me proud beauty! This gives access t' t' inside o' t' internal body tube, for filleting.

As I'm plannin' on flyin' with a 29mm RMS, ya bilge rat, no thrust rin' is required. Blimey! Begad! But I do need a retention system. Well, blow me down! Begad! I decide on a Kaplow Klip style affair. Aye aye! Two M5 nuts are glued t' t' forward side o' t' aft centerin' ring. Aye aye! Then a hole is drilled in t' center o' t' nuts, matey, me bucko, through t' centerin' ring, shiver me timbers, shiver me timbers, me hearties, takin' care t' use a small enough drill bit that t' threads aren't stripped. Avast! Once dry, shiver me timbers, shiver me timbers, bolts are screwed into t' nuts and through t' plywood o' t' centerin' ring. Begad! Avast! T' clips are made from aluminium, shiver me timbers, bent t' shape by hammerin' them over, matey, while held in a vice. Well, blow me down! Avast, me proud beauty! T' unformed blanks were about 10mm wide and 35mm long.

Fins & Fin Pods

Fins & Fin Pods

After much sketching, me hearties, I eventually determine that t' most aesthetically pleasin' fin pattern (to me anyhow) is such that t' fins oposite each other on t' body form a semicircle, when viewed side-on. Well, blow me down! This neccessitated a four fin design, me hearties, which was fine. Arrr! Blimey! I reckoned I needed all t' stability I could get. It wasn't consistant with Tin Tin, arrr, but what t' hey, artistic license! Given t' flimsiness o' t' outer shell, t' fins have t' be through-the-wall. Ahoy! In t' end I descide t' make them pass through t' wall o' t' inner body tube too. Avast! That way they can be securely mounted t' t' motor mount. Avast, me proud beauty! This means that all t' major structural elements are glued t' each other, givin' maximum strength.

T' more I think about t' fins pods, t' more they seem like a nose cone, me bucko, but rounded at t' base, matey, where t' shoulder would normally be. Well, blow me down! I've had custom nose cones made before. Ahoy! I sketch a plan and get them made by Rockets & Things. Aye aye! I order five, arrr, one for emergencies! They arrive within a few days, me hearties, and I'm well pleased, exactly t' right shape, arrr, and all identical. But how am I goin' t' attach them?

Rear view o' fins

Close up o' fin mounting

Rear view o' fins

While I ponder this I cut out t' fins from 3mm plywood. Avast! Blimey! I leave a large tab for through-the-wall mounting. Well, blow me down! Blimey! I'm still wonderin' how t' mount t' pods. Ya scallywag! Blimey! Shouls I try t' slot them and slip them over t' fin? Tricky. Cut t' fin t' t' shape o' t' pod and make a butt-joint? Trickier. Ya scallywag! Blimey! Eventually I take t' brute force method and saw t' pods in half along their vertical axis. Begad! Blimey! T' thickness o' t' saw takes about 1.5mm from t' diameter, arrr, measure at right angles t' t' cut. Avast, me proud beauty! Blimey! Avast! Blimey! A little sanding, arrr, required anyway t' level t' cut up a bit, me bucko, removes 3mm in total. Blimey! Blimey! Ya scallywag! Blimey! When placed on either side o' t' fin, they are back t' t' original diameter. Ahoy! Blimey! Ahoy! Blimey! T' pod halves are simply glued t' either side o' a fin with carpenters glue, clamped up and left t' dry.

Next step is t' seal t' balsa and plywood. I use several coats o' sandin' sealer, me hearties, with a light sandin' o' 120 grit betwixt coats. Avast! Next I fill t' joins. Blimey! Arrr! I've tried all kinds o' filler. Avast! Avast, me proud beauty! P38, specialist modelling filler, Ronseal exterior wood filler all sorts, and they all smell terrible! I found t' P38 dries too smartly and sets too hard. Blimey! T' modellin' filler is expensive and doesn't stick t' phenolic very well. Avast! I like t' Ronseal best, it was workable longer, ya bilge rat, and easier t' sand, me hearties, ya bilge rat, ya bilge rat, but heavy. Avast! Begad! I like t' fill t' spirals in phenolic tubin' with this. Begad! In t' end I use t' specialist modelling filler because it's light. I don't need any extra weight at t' that end o' t' rocket! It takes a lot o' filler around t' join betwixt t' fin pod halves and t' fin. Arrr! Begad! I apply a few light coats o' primer t' t' pods, me hearties, sandin' betwixt coats.

Fin Assembly

To allow for through-the-wall mountin' o' t' fins, me bucko, ya bilge rat, I need t' cut fin slots in both t' inner body tube and t' outer body shell. I use a Dremmel for this with a disc cutter. Ya scallywag! T' slots in t' inner body tube are true closed slots for strength. Avast, me proud beauty! Avast, me proud beauty! I reason that it will be easier t' attach t' fins t' t' inner body tube, before t' outer body shell is fitted. Ahoy! If I do that I won't be able t' get t' outer body shell on, so I make those slots all t' way t' t' bottom. Well, blow me down! This reduces teh strength, but t' body shell isn't really stuctural anyway. Arrr! Avast, me proud beauty! T' fins are slotted into place in t' inner body and epoxied t' t' motor mount. Epoxy fillets are made where t' fins attach t' t' motor mount, and on both t' inside and outside o' t' inner body. T' slots are longe enough t' stretch from t' forward centerin' rin' t' t' aft centerin' ring. This all adds strength, but weight as well. Begad! Finally t' aft centerin' rin' is epoxied into position.

Nose Cone

I need a coupler tube that will fit into t' plastic tubin' o' t' inner body. Begad! Blimey! Arrr! Blimey! I don't have any, shiver me timbers, so make a short tlength from t' same tubing. Ahoy! Blimey! Begad! Blimey! I simply cut out a slot o' t' correct width t' reduce t' outer circimference t' that o' t' inner circumference o' t' opriginal tube. Blimey! Blimey! Well, blow me down! Blimey! Is epoxy t' cut out strip t' t' back o' t' join for reinforcement. Begad! Blimey! Begad! Blimey! This tube is first superglued and then epoxied into t' nose cone.

Fully assembled

Fully assembled, shiver me timbers, aft view

Final Assembly

Just in time, shiver me timbers, I realise that t' outer shell isn't goin' t' be strong enough t' attach a launch lug to, me bucko, without some form o' reinforcement. I cut a small rectangulat slot in t' side o' t' body shell. I epoxy some plywood t' t' interior o' t' shell, behind t' slot. Arrr! Well, blow me down! T' epoxy gunges through t' slot, and I use it t' fix t' launch lug in place.

T' body shell slips on easily, arrr, and is epoxied initially t' just t' forward end. Ahoy! Blimey! Actually t' inner tube is glued t' t' centerin' rin' previously fixed into t' outer shell. Aye aye! Arrr! Because t' aft and o' t' shell is flappin' about a bit, arrr, I tack it into place with CA. Ya scallywag! Then I apply a liberal application o' epoxy, t' t' aft end and also t' t' fin roots. Arrr! Once it's all set, it gets sanded and filled. Well, blow me down! Avast! T' epoxy fillets in t' fin roots turn out a bit rough, shiver me timbers, so I rebuild t' fillets with Ronseal. Prime, matey, sand, ya bilge rat, fill, arrr, shiver me timbers, sand, shiver me timbers, me hearties, primne, me hearties, sand, fill, ya bilge rat, ya bilge rat, sand, shiver me timbers, prime, sand. Well, blow me down! Or somethin' like that. It's ready. Ya scallywag! Aye aye! I rub it down lightly with 200 grit wet and dry.

Swin' test

Because o' t' odd shape, matey, I didn't trust t' stability factor given by Rocksim. Ya scallywag! Begad! In fact rocksim reckoned it wasn't stable by a mile. Avast, me proud beauty! Ya scallywag! But you don't always need more than a calibre o' stability on a stubby rocket anyway. Arrr! I still reckon I need nose weight, but what t' use? Lead would be good, but where can I get it and how much is it goin' t' cost, shiver me timbers, me hearties, shiver me timbers, I'll probably have t' buy it by t' yard! My eldest son, me bucko, me bucko, Shaun has t' answer, doubloon o' t' realm. Begad! One pees are quite heavy for their size. Well, blow me down! Avast! I add 200g o' weight t' t' nose. Ahoy! Avast, me proud beauty! Rocksim says "marginal". Avast! I decide that t' only way t' be certain is a swin' test.

Now, arrr, this be t' biggest rocket I've ever swung test, matey, and it turns out me garden isn't quite big enough, nay when t' washin' is dryin' anyway. Ahoy! Blimey! So I comandeer t' next door neighbours garden, because they're nay in. Blimey! Blimey! Blimey! Blimey! Needless t' say they came home durin' t' swin' test, arrr, but they're used t' it by now. Avast, me proud beauty! Blimey! Avast! Blimey! Anyway I start t' swing, and it jumps into t' right orientation. Begad! Blimey! Aye aye! Blimey! Great. I do a few more sims, matey, me hearties, usin' different motors, and it doesn't go very high. Begad! Blimey! So I reduce t' nose weight t' about 100g, or t' be more exact 31p. Well, blow me down! Blimey! Another quick swin' test and it's still good. Avast! Blimey! I blue t' nose wight into t' nose with epoxy. Once t' epoxy is dry I realise that I have no where t' attach t' shock cord to. I drill a hole into t' nose weight, shiver me timbers, matey, shiver me timbers, fill it with epoxy, and insert an eye hook. Avast, me proud beauty! Blimey! Sorted.

Primed

Primed, aft view

Painting

Finish

I had been primin' as I went along, shiver me timbers, so as soon as t' fin fillets were complete, it only took another couple o' coats t' get a nice smooth finish. T' primer used throughout is Halfords car paint, matey, shiver me timbers, in t' aerosol cans. Avast, arrr, me proud beauty! I also use Halfords for t' main colours. Avast! Rover Diamond White and Volkswagen Mars Red. Seems appropriate really. First I spray t' whole rocket white. I do about 3 coats, me hearties, lightly sandin' betwixt each. Aye aye! I had decided much earlier on that a full Tin Tin chequerboard was far too much work, shiver me timbers, so I had scaled t' pattern down t' two bands, shiver me timbers, o' four quadrants. Blimey! Well, blow me down! First I masked off every thin' above t' fins, matey, shiver me timbers, me bucko, and painted everythin' below red. Avast, me proud beauty! Ya scallywag! I also painted t' nose cone. T' red covered really well in only two light coats. Ya scallywag! Next I painted t' two red quadrants o' t' lower band. Begad! So far so good. Avast, me proud beauty! T' red quadrants o' t' upper band were hardest, bacause it be hard t' get a t' maskin' tape into exactly t' right position t' make t' square corners o' red meet exactly. Begad! T' maskin' be t' hardest part o' t' entire project. Aye aye! T' red paint crept underneath t' tape in certain areas, and in other areas t' tape lifted off some small areas o' white when removed. Blimey! But I managed t' touch those defects up, ya bilge rat, and I'm pretty pleased with t' final outcome. Aye aye! It's t' best finish o' all t' rockets I've made so far. Blimey! It needs goin' over with 400 grit wet and dry and a coat o' lacquer applying, but thar's no time. Aye aye! UKRA 2000 starts tomorrow!

Flight Test

I use about 150mm o' Nomex® sheath over t' nylon strap, and a Nomex® sheet above that t' protect t' chute. Avast, shiver me timbers, me proud beauty! About 70mm o' 20mm elastic attach t' nose cone t' t' nylon strap. A 34" PML chute is atached t' t' elastic too. Avast! I decide upon a G104 blue thunder reload. Avast! It's only just a G, shiver me timbers, but it gets t' rocket movin' quick. Well, blow me down! I reckon t' sooner I can get it up t' stable speed t' better.

It rains on Friday and Saturday, me hearties, and I'm hesitant t' fly. Ahoy! Sunday is better, matey, and I decide t' fly before I take up spottin' duty. On t' Staryrday I'd had it on a rod, and found it be a little tight, but I had found a slightly smaller diametr rod, which was perfect. Begad! Blimey! Blimey! I was pretty nervous durin' t' countdown, me bucko, and we had a hold for a low flyin' aircraft, but finally, me hearties, t' moment comes. Ya scallywag! Blimey! Blimey! 5, me hearties, 4, 3, 2, shiver me timbers, 1 ignition. Well, blow me down! Aye aye! Blimey! It's away! Blimey! Great flight! Blimey! It arced a bit after it left t' rod, ya bilge rat, but very smooth, matey, arrr, no sign o' a wobble or instability o' any kind. Ya scallywag! Blimey! T' ejection fired right at apogee, me hearties, and Tintinique drifted slowly down, landin' approximately 40" from t' pad. Avast, me proud beauty! There is a little damage t' t' nose cone,I can't figure out if it happened in flight or on impact with t' ground, matey, but I couldn't find t' piece chipped out so it probably happened in t' air. Begad! Blimey! Easy t' fix, next flight comin' soon...

Nosecone damage