Tintinique

Tintinique

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

Nestlé time capsule

Centerin' rin' in position

Time Capsules

In October 99, I attended K-Lob in Lincolnshire. Blimey! Amongst t' rockets thar be somethin' very different. Avast, me proud beauty! Avast, arrr, me proud beauty! It looked like a 50's retro rocket. Aye aye! It was great. Aye aye! How on earth did they make t' body for that? It turns out, matey, 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, and dig it up in t' future. Arrr! 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, t' capsule itself, shiver me timbers, was made from a shape resemblin' t' body o' a typical sci-fi or cartoon rocket. Better still, t' screw-on lid was easily convertible into a removeable nose cone. Begad! Whoever it be I'd love t' ask them why they did it. Well, blow me down! I buy two, one for a podded Tin Tin rocket, me bucko, t' other for spare.

Anyway, me hearties, time passes and every time I go t' a launch thar's another time capsule. Well, blow me down! I've got t' build this thing. I decide t' build it for RMR DesCon6. Begad! Blimey! Time passes. DesCon6 begins. Begad! Blimey! Avast, me proud beauty! Blimey! Time passes. 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. Ya scallywag! I dig out t' time capsule. I dig out cover scans o' t' books Destination Moon, arrr, ya bilge rat, 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, and start t' think about t' body instead. Avast, me proud beauty! Time capsules are cheaply moulded, thick in some places thin in others, arrr, shiver me timbers, and very flexible. Avast! I had decided that it was t' have a 29mm motor mount t' utilise t' short 29mm casings I had, arrr, ya bilge rat, and so t' body would need t' be reinforced. Blimey! It needs an internal body tube, t' give structural strength and provide somethin' t' attach other components to, 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, me bucko, and this seemed ideal. Ya scallywag! I could have used standard 3" PML phenolic, 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, shiver me timbers, and hacked a 3" diameter hole in t' base. Blimey! T' openin' at t' top o' t' time casule was larger than 3", so I cut a 3mm thick plywood centerin' ring, arrr, ya bilge rat, and glued it in place, under t' shoulder. Blimey! Well, blow me down! 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, me bucko, matey, so I draw some rough sketches, then some rough, dimensioned sketches. Ahoy! Arrr! My son, ya bilge rat, James, draws some sketches. I'm nay really gettin' anywhere. It's all free hand and nay very satisfactory. Rocksim! T' time capsule is suprisingly easy t' describe usin' a parabolic nose cone, matey, and a couple o' eliptical transitions. Now, 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, but at least it helps visualise what t' rocket will look like when complete.

Inner body tube, motor mount

Inner body tube, parachute bay

Aft centerin' ring, retainin' nuts

Aft centerin' ring, retainin' clips

Construction

Motor Mount & Retention

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

T' forward centerin' rin' be epoxied t' t' forward end o' t' motor mount and allowed t' cure. T' aft cebterin' rein' was fitted, with no epoxy, ya bilge rat, ya bilge rat, t' t' aft o' t' motor mount. T' forward centerin' rin' was epoxied into t' internal motor mount. Arrr! Once t' forward centerin' rin' was fixed, arrr, ya bilge rat, matey, t' aft centerin' rin' be removed. Aye aye! Ya scallywag! 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. Avast, me proud beauty! But I do need a retention system. Blimey! I decide on a Kaplow Klip style affair. Two M5 nuts are glued t' t' forward side o' t' aft centerin' ring. Then a hole is drilled in t' center o' t' nuts, ya bilge rat, matey, through t' centerin' ring, takin' care t' use a small enough drill bit that t' threads aren't stripped. Avast, me proud beauty! Once dry, shiver me timbers, me hearties, bolts are screwed into t' nuts and through t' plywood o' t' centerin' ring. Blimey! T' clips are made from aluminium, shiver me timbers, shiver me timbers, bent t' shape by hammerin' them over, ya bilge rat, shiver me timbers, while held in a vice. Ya scallywag! Ya scallywag! 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, matey, arrr, when viewed side-on. 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, me bucko, but what t' hey, matey, matey, arrr, artistic license! Given t' flimsiness o' t' outer shell, me bucko, 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. Avast! Aye aye! That way they can be securely mounted t' t' motor mount. This means that all t' major structural elements are glued t' each other, me bucko, givin' maximum strength.

T' more I think about t' fins pods, t' more they seem like a nose cone, but rounded at t' base, where t' shoulder would normally be. I've had custom nose cones made before. Avast! Blimey! I sketch a plan and get them made by Rockets & Things. Blimey! Blimey! I order five, me bucko, one for emergencies! Blimey! They arrive within a few days, matey, 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, me proud beauty! I leave a large tab for through-the-wall mounting. Ya scallywag! I'm still wonderin' how t' mount t' pods. Shouls I try t' slot them and slip them over t' fin? Tricky. Well, blow me down! Cut t' fin t' t' shape o' t' pod and make a butt-joint? Trickier. Begad! Aye aye! Eventually I take t' brute force method and saw t' pods in half along their vertical axis. Blimey! T' thickness o' t' saw takes about 1.5mm from t' diameter, measure at right angles t' t' cut. A little sanding, me hearties, required anyway t' level t' cut up a bit, removes 3mm in total. Begad! When placed on either side o' t' fin, they are back t' t' original diameter. Aye aye! 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. Well, me hearties, blow me down! Blimey! I use several coats o' sandin' sealer, with a light sandin' o' 120 grit betwixt coats. Blimey! Blimey! Avast! Blimey! Next I fill t' joins. Avast! Blimey! Ya scallywag! Blimey! I've tried all kinds o' filler. Begad! Blimey! P38, arrr, specialist modelling filler, shiver me timbers, shiver me timbers, Ronseal exterior wood filler all sorts, and they all smell terrible! I found t' P38 dries too smartly and sets too hard. Ahoy! T' modellin' filler is expensive and doesn't stick t' phenolic very well. Avast, me proud beauty! I like t' Ronseal best, it was workable longer, and easier t' sand, shiver me timbers, but heavy. Blimey! I like t' fill t' spirals in phenolic tubin' with this. Arrr! In t' end I use t' specialist modelling filler because it's light. Avast! 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. Begad! 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, I need t' cut fin slots in both t' inner body tube and t' outer body shell. Ya scallywag! I use a Dremmel for this with a disc cutter. Ahoy! T' slots in t' inner body tube are true closed slots for strength. Ahoy! Begad! Blimey! I reason that it will be easier t' attach t' fins t' t' inner body tube, shiver me timbers, before t' outer body shell is fitted. Aye aye! 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. Begad! Blimey! Blimey! This reduces teh strength, ya bilge rat, ya bilge rat, but t' body shell isn't really stuctural anyway. Aye aye! Blimey! 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, ya bilge rat, and on both t' inside and outside o' t' inner body. Ahoy! Avast, me bucko, me proud beauty! Blimey! T' slots are longe enough t' stretch from t' forward centerin' rin' t' t' aft centerin' ring. This all adds strength, shiver me timbers, shiver me timbers, me bucko, 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. Ya scallywag! Avast, me proud beauty! I don't have any, so make a short tlength from t' same tubing. 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. Ya scallywag! Is epoxy t' cut out strip t' t' back o' t' join for reinforcement. This tube is first superglued and then epoxied into t' nose cone.

Fully assembled

Fully assembled, aft view

Final Assembly

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

T' body shell slips on easily, arrr, ya bilge rat, and is epoxied initially t' just t' forward end. Blimey! Actually t' inner tube is glued t' t' centerin' rin' previously fixed into t' outer shell. Blimey! Because t' aft and o' t' shell is flappin' about a bit, I tack it into place with CA. Well, me hearties, blow me down! Then I apply a liberal application o' epoxy, t' t' aft end and also t' t' fin roots. Once it's all set, it gets sanded and filled. T' epoxy fillets in t' fin roots turn out a bit rough, so I rebuild t' fillets with Ronseal. Aye aye! Begad! Prime, me bucko, sand, me bucko, fill, sand, primne, ya bilge rat, me hearties, sand, fill, arrr, sand, matey, prime, sand. Or somethin' like that. Blimey! Blimey! It's ready. Begad! 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. Ahoy! In fact rocksim reckoned it wasn't stable by a mile. But you don't always need more than a calibre o' stability on a stubby rocket anyway. Aye aye! I still reckon I need nose weight, matey, but what t' use? Lead would be good, arrr, but where can I get it and how much is it goin' t' cost, me bucko, I'll probably have t' buy it by t' yard! My eldest son, ya bilge rat, Shaun has t' answer, matey, doubloon o' t' realm. One pees are quite heavy for their size. Well, blow me down! I add 200g o' weight t' t' nose. Arrr! Ya scallywag! Rocksim says "marginal". Avast, me proud beauty! Blimey! Ya scallywag! Blimey! I decide that t' only way t' be certain is a swin' test.

Now, matey, matey, matey, this be t' biggest rocket I've ever swung test, arrr, shiver me timbers, and it turns out me garden isn't quite big enough, me bucko, nay when t' washin' is dryin' anyway. Arrr! Well, me bucko, blow me down! So I comandeer t' next door neighbours garden, because they're nay in. Aye aye! Needless t' say they came home durin' t' swin' test, ya bilge rat, but they're used t' it by now. Anyway I start t' swing, and it jumps into t' right orientation. Begad! Great. Ya scallywag! Begad! I do a few more sims, usin' different motors, shiver me timbers, matey, and it doesn't go very high. Begad! So I reduce t' nose weight t' about 100g, or t' be more exact 31p. Blimey! Another quick swin' test and it's still good. Begad! I blue t' nose wight into t' nose with epoxy. Avast! Once t' epoxy is dry I realise that I have no where t' attach t' shock cord to. Well, blow me down! I drill a hole into t' nose weight, arrr, fill it with epoxy, shiver me timbers, and insert an eye hook. Avast! 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. Well, blow me down! T' primer used throughout is Halfords car paint, in t' aerosol cans. Ya scallywag! I also use Halfords for t' main colours. Ya scallywag! Begad! Rover Diamond White and Volkswagen Mars Red. Blimey! Ahoy! Seems appropriate really. Well, blow me down! First I spray t' whole rocket white. I do about 3 coats, lightly sandin' betwixt each. Avast, me proud beauty! I had decided much earlier on that a full Tin Tin chequerboard was far too much work, arrr, matey, so I had scaled t' pattern down t' two bands, o' four quadrants. Ya scallywag! First I masked off every thin' above t' fins, and painted everythin' below red. I also painted t' nose cone. T' red covered really well in only two light coats. Avast! Well, matey, blow me down! Next I painted t' two red quadrants o' t' lower band. Arrr! Avast! So far so good. Begad! Begad! 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. Avast! T' maskin' be t' hardest part o' t' entire project. T' red paint crept underneath t' tape in certain areas, me bucko, arrr, and in other areas t' tape lifted off some small areas o' white when removed. But I managed t' touch those defects up, matey, and I'm pretty pleased with t' final outcome. Ahoy! It's t' best finish o' all t' rockets I've made so far. It needs goin' over with 400 grit wet and dry and a coat o' lacquer applying, 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, me bucko, and a Nomex® sheet above that t' protect t' chute. Arrr! Begad! About 70mm o' 20mm elastic attach t' nose cone t' t' nylon strap. Aye aye! Avast! A 34" PML chute is atached t' t' elastic too. Begad! I decide upon a G104 blue thunder reload. Aye aye! 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, matey, and I'm hesitant t' fly. Ya scallywag! 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, shiver me timbers, and found it be a little tight, but I had found a slightly smaller diametr rod, me hearties, me hearties, which was perfect. I was pretty nervous durin' t' countdown, and we had a hold for a low flyin' aircraft, but finally, ya bilge rat, t' moment comes. Avast! 5, 4, shiver me timbers, shiver me timbers, 3, ya bilge rat, arrr, 2, me bucko, me bucko, 1 ignition. Begad! It's away! Great flight! It arced a bit after it left t' rod, matey, but very smooth, matey, no sign o' a wobble or instability o' any kind. Begad! T' ejection fired right at apogee, and Tintinique drifted slowly down, landin' approximately 40" from t' pad. Blimey! 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, ya bilge rat, me bucko, but I couldn't find t' piece chipped out so it probably happened in t' air. Avast, me proud beauty! Begad! Easy t' fix, next flight comin' soon...

Nosecone damage