Tintinique

Tintinique

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

Nestlé time capsule

Centerin' rin' in position

Time Capsules

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

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

I ignore t' question o' t' fin pods, arrr, and start t' think about t' body instead. Avast! Begad! Time capsules are cheaply moulded, thick in some places thin in others, me hearties, arrr, and very flexible. Well, blow me down! I had decided that it was t' have a 29mm motor mount t' utilise t' short 29mm casings I had, and so t' body would need t' be reinforced. It needs an internal body tube, ya bilge rat, matey, t' give structural strength and provide somethin' t' attach other components to, ya bilge rat, me hearties, shiver me timbers, leavin' t' time capsule t' form only an outer shell. I had some 3" plastic tubin' that I had got from Ziggy at K-Lob, and this seemed ideal. Blimey! Blimey! I could have used standard 3" PML phenolic, ya bilge rat, or even quantum tubing, shiver me timbers, 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, ya bilge rat, shiver me timbers, and hacked a 3" diameter hole in t' base. Arrr! T' openin' at t' top o' t' time casule was larger than 3", so I cut a 3mm thick plywood centerin' ring, and glued it in place, me hearties, shiver me timbers, under t' shoulder. Well, blow me down! Blimey! 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, so I draw some rough sketches, then some rough, me bucko, dimensioned sketches. Aye aye! My son, ya bilge rat, James, draws some sketches. I'm nay really gettin' anywhere. It's all free hand and nay very satisfactory. Well, blow me down! Arrr! Rocksim! T' time capsule is suprisingly easy t' describe usin' a parabolic nose cone, and a couple o' eliptical transitions. Arrr! Avast! Now, me hearties, Rocksim isn't really designed for this shape o' rocket, me bucko, and so I'm nay goin' t' trust what it says about stability, shiver me timbers, but at least it helps visualise what t' rocket will look like when complete.

Inner body tube, motor mount

Inner body tube, ya bilge rat, parachute bay

Aft centerin' ring, retainin' nuts

Aft centerin' ring, me hearties, ya bilge rat, retainin' clips

Construction

Motor Mount & Retention

I do have a short piece o' PML 29mm motor mount. Avast, me proud beauty! I had originally intended for t' motor mount t' run t' length o' t' body, shiver me timbers, with t' space for a parachute betwixt t' internal body tube and t' motor mount. Aye aye! Begad! 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. Blimey! So, me bucko, I decide t' have a short motor mount, givin' t' full internal diameter o' t' internal tube for a parachute. Ya scallywag! I cut two, me bucko, 3mm thick, arrr, plywood centerin' rings that fit over t' motor mount and into t' plastic tube. Avast! T' forward centerin' rin' has a notch t' pass a nylon strap. Arrr! T' strap is about25mm wide and 400mm long. T' nylon strap will provide an attachment point for t' elastic shock cord. T' strap is t' epoxied t' t' inside o' t' internal body tube. Begad! 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. Begad! Blimey! Ahoy! Blimey! T' aft cebterin' rein' was fitted, ya bilge rat, with no epoxy, me bucko, t' t' aft o' t' motor mount. Blimey! Blimey! Ahoy! Blimey! T' forward centerin' rin' was epoxied into t' internal motor mount. Arrr! Blimey! Avast, me proud beauty! Blimey! Once t' forward centerin' rin' was fixed, t' aft centerin' rin' be removed. Begad! Blimey! This gives access t' t' inside o' t' internal body tube, for filleting.

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

Fins & Fin Pods

Fins & Fin Pods

After much sketching, 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. Arrr! This neccessitated a four fin design, which be fine. I reckoned I needed all t' stability I could get. It wasn't consistant with Tin Tin, shiver me timbers, but what t' hey, artistic license! Given t' flimsiness o' t' outer shell, ya bilge rat, t' fins have t' be through-the-wall. Blimey! Blimey! In t' end I descide t' make them pass through t' wall o' t' inner body tube too. Well, blow me down! That way they can be securely mounted t' t' motor mount. This means that all t' major structural elements are glued t' each other, givin' maximum strength.

T' more I think about t' fins pods, me hearties, t' more they seem like a nose cone, arrr, matey, matey, but rounded at t' base, where t' shoulder would normally be. Aye aye! Ya scallywag! I've had custom nose cones made before. Begad! Begad! I sketch a plan and get them made by Rockets & Things. I order five, one for emergencies! They arrive within a few days, and I'm well pleased, me hearties, ya bilge rat, exactly t' right shape, ya bilge rat, shiver me timbers, 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. Begad! I leave a large tab for through-the-wall mounting. Blimey! I'm still wonderin' how t' mount t' pods. Avast! Shouls I try t' slot them and slip them over t' fin? Tricky. Arrr! Cut t' fin t' t' shape o' t' pod and make a butt-joint? Trickier. Avast, me proud beauty! Eventually I take t' brute force method and saw t' pods in half along their vertical axis. T' thickness o' t' saw takes about 1.5mm from t' diameter, matey, me bucko, measure at right angles t' t' cut. Avast! Ya scallywag! A little sanding, required anyway t' level t' cut up a bit, removes 3mm in total. Begad! Arrr! When placed on either side o' t' fin, me bucko, they are back t' t' original diameter. Ahoy! 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. Avast! I use several coats o' sandin' sealer, shiver me timbers, with a light sandin' o' 120 grit betwixt coats. Ahoy! Aye aye! Blimey! Next I fill t' joins. Well, blow me down! Blimey! I've tried all kinds o' filler. Arrr! Blimey! P38, specialist modelling filler, me hearties, Ronseal exterior wood filler all sorts, and they all smell terrible! I found t' P38 dries too smartly and sets too hard. T' modellin' filler is expensive and doesn't stick t' phenolic very well. Well, blow me down! I like t' Ronseal best, it was workable longer, ya bilge rat, and easier t' sand, arrr, but heavy. Blimey! I like t' fill t' spirals in phenolic tubin' with this. Blimey! Aye aye! 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. Avast! I apply a few light coats o' primer t' t' pods, sandin' betwixt coats.

Fin Assembly

To allow for through-the-wall mountin' o' t' fins, I need t' cut fin slots in both t' inner body tube and t' outer body shell. Aye aye! I use a Dremmel for this with a disc cutter. Avast! Ahoy! Blimey! T' slots in t' inner body tube are true closed slots for strength. I reason that it will be easier t' attach t' fins t' t' inner body tube, before t' outer body shell is fitted. If I do that I won't be able t' get t' outer body shell on, ya bilge rat, matey, so I make those slots all t' way t' t' bottom. This reduces teh strength, but t' body shell isn't really stuctural anyway. T' fins are slotted into place in t' inner body and epoxied t' t' motor mount. Begad! Blimey! Epoxy fillets are made where t' fins attach t' t' motor mount, matey, ya bilge rat, and on both t' inside and outside o' t' inner body. Avast! T' slots are longe enough t' stretch from t' forward centerin' rin' t' t' aft centerin' ring. Begad! Avast! Blimey! This all adds strength, but weight as well. 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. Ahoy! I don't have any, so make a short tlength from t' same tubing. Aye aye! 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. Avast! Is epoxy t' cut out strip t' t' back o' t' join for reinforcement. Begad! This tube is first superglued and then epoxied into t' nose cone.

Fully assembled

Fully assembled, aft view

Final Assembly

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

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

Swin' test

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

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

Primed

Primed, aft view

Painting

Finish

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

Flight Test

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

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

Nosecone damage