Tintinique

Tintinique

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

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

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

Inner body tube, shiver me timbers, arrr, me bucko, parachute bay

Aft centerin' ring, arrr, retainin' nuts

Aft centerin' ring, matey, retainin' clips

Construction

Motor Mount & Retention

I do have a short piece o' PML 29mm motor mount. Ahoy! Well, 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. 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. So, I decide t' have a short motor mount, givin' t' full internal diameter o' t' internal tube for a parachute. Begad! Arrr! I cut two, shiver me timbers, 3mm thick, 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. Aye aye! T' strap is about25mm wide and 400mm long. Avast! Avast, me proud beauty! T' nylon strap will provide an attachment point for t' elastic shock cord. Avast! T' strap is t' epoxied t' t' inside o' t' internal body tube. 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. Well, blow me down! Ya scallywag! T' aft cebterin' rein' was fitted, with no epoxy, t' t' aft o' t' motor mount. T' forward centerin' rin' be epoxied into t' internal motor mount. Once t' forward centerin' rin' was fixed, me hearties, me hearties, t' aft centerin' rin' was removed. Ahoy! 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. Arrr! Begad! But I do need a retention system. Avast, matey, me proud beauty! I decide on a Kaplow Klip style affair. Begad! Avast, me proud beauty! Two M5 nuts are glued t' t' forward side o' t' aft centerin' ring. Begad! Then a hole is drilled in t' center o' t' nuts, through t' centerin' ring, arrr, shiver me timbers, takin' care t' use a small enough drill bit that t' threads aren't stripped. Avast, me proud beauty! Once dry, bolts are screwed into t' nuts and through t' plywood o' t' centerin' ring. Avast, me proud beauty! Arrr! T' clips are made from aluminium, me bucko, bent t' shape by hammerin' them over, arrr, while held in a vice. 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. This neccessitated a four fin design, which be fine. Aye aye! Blimey! Blimey! Blimey! I reckoned I needed all t' stability I could get. Ya scallywag! Blimey! Blimey! Blimey! It wasn't consistant with Tin Tin, matey, but what t' hey, me bucko, artistic license! Blimey! Blimey! Blimey! Given t' flimsiness o' t' outer shell, t' fins have t' be through-the-wall. Arrr! Blimey! Well, blow me down! Blimey! Blimey! Blimey! In t' end I descide t' make them pass through t' wall o' t' inner body tube too. Well, blow me down! Blimey! Ya scallywag! Blimey! Blimey! Blimey! That way they can be securely mounted t' t' motor mount. Aye aye! Blimey! 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, but rounded at t' base, ya bilge rat, where t' shoulder would normally be. Ahoy! I've had custom nose cones made before. Well, me hearties, blow me down! I sketch a plan and get them made by Rockets & Things. I order five, ya bilge rat, one for emergencies! They arrive within a few days, and I'm well pleased, me hearties, exactly t' right shape, ya bilge rat, shiver me timbers, matey, and all identical. Aye aye! 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. Ya scallywag! I leave a large tab for through-the-wall mounting. Begad! I'm still wonderin' how t' mount t' pods. Aye aye! 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. Ahoy! Eventually I take t' brute force method and saw t' pods in half along their vertical axis. Begad! Aye aye! T' thickness o' t' saw takes about 1.5mm from t' diameter, arrr, arrr, measure at right angles t' t' cut. Begad! A little sanding, required anyway t' level t' cut up a bit, me hearties, me hearties, me hearties, removes 3mm in total. When placed on either side o' t' fin, arrr, they are back t' t' original diameter. Begad! 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, matey, with a light sandin' o' 120 grit betwixt coats. Begad! Blimey! Next I fill t' joins. Begad! Blimey! Avast, me proud beauty! Blimey! I've tried all kinds o' filler. Aye aye! Blimey! P38, specialist modelling filler, matey, Ronseal exterior wood filler all sorts, matey, and they all smell terrible! I found t' P38 dries too smartly and sets too hard. Well, blow me down! Avast! T' modellin' filler is expensive and doesn't stick t' phenolic very well. Ahoy! I like t' Ronseal best, it be workable longer, and easier t' sand, me bucko, but heavy. Ya scallywag! I like t' fill t' spirals in phenolic tubin' with this. Avast, me proud beauty! In t' end I use t' specialist modelling filler because it's light. Aye aye! 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, me proud beauty! Ahoy! I apply a few light coats o' primer t' t' pods, me bucko, sandin' betwixt coats.

Fin Assembly

To allow for through-the-wall mountin' o' t' fins, shiver me timbers, ya bilge rat, I need t' cut fin slots in both t' inner body tube and t' outer body shell. Avast, me proud beauty! I use a Dremmel for this with a disc cutter. Well, blow me down! T' slots in t' inner body tube are true closed slots for strength. Well, blow me down! Ahoy! I reason that it will be easier t' attach t' fins t' t' inner body tube, shiver me timbers, matey, before t' outer body shell is fitted. Ahoy! 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. Begad! This reduces teh strength, matey, 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. Epoxy fillets are made where t' fins attach t' t' motor mount, and on both t' inside and outside o' t' inner body. Begad! Begad! T' slots are longe enough t' stretch from t' forward centerin' rin' t' t' aft centerin' ring. Aye aye! This all adds strength, but weight as well. Blimey! 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. Well, blow me down! Arrr! 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. Begad! 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, matey, me hearties, aft view

Final Assembly

Just in time, arrr, I realise that t' outer shell isn't goin' t' be strong enough t' attach a launch lug to, without some form o' reinforcement. Ahoy! Avast! 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. T' epoxy gunges through t' slot, 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. Avast! Actually t' inner tube is glued t' t' centerin' rin' previously fixed into t' outer shell. Avast, me proud beauty! Avast, me proud beauty! Because t' aft and o' t' shell is flappin' about a bit, I tack it into place with CA. Avast, me proud beauty! Then I apply a liberal application o' epoxy, t' t' aft end and also t' t' fin roots. Aye aye! Once it's all set, it gets sanded and filled. Avast! T' epoxy fillets in t' fin roots turn out a bit rough, so I rebuild t' fillets with Ronseal. Ya scallywag! Prime, sand, arrr, fill, me bucko, me hearties, sand, ya bilge rat, primne, shiver me timbers, ya bilge rat, sand, fill, me hearties, sand, arrr, prime, sand. Avast! Avast, me proud beauty! Or somethin' like that. Begad! It's ready. Avast, me proud beauty! 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. Avast, me hearties, me proud beauty! In fact rocksim reckoned it wasn't stable by a mile. Ya scallywag! But you don't always need more than a calibre o' stability on a stubby rocket anyway. Ahoy! I still reckon I need nose weight, but what t' use? Lead would be good, me hearties, 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, shiver me timbers, doubloon o' t' realm. Avast! One pees are quite heavy for their size. I add 200g o' weight t' t' nose. Begad! Begad! Rocksim says "marginal". Avast! I decide that t' only way t' be certain is a swin' test.

Now, this be t' biggest rocket I've ever swung test, 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, shiver me timbers, matey, arrr, because they're nay in. Aye aye! Arrr! Needless t' say they came home durin' t' swin' test, me hearties, but they're used t' it by now. Begad! Anyway I start t' swing, me bucko, ya bilge rat, and it jumps into t' right orientation. Well, matey, blow me down! Great. Ya scallywag! Avast! I do a few more sims, usin' different motors, arrr, and it doesn't go very high. Begad! So I reduce t' nose weight t' about 100g, arrr, or t' be more exact 31p. Another quick swin' test and it's still good. Well, blow me down! I blue t' nose wight into t' nose with epoxy. Ya scallywag! Begad! 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, me bucko, me bucko, me hearties, fill it with epoxy, and insert an eye hook. Blimey! Sorted.

Primed

Primed, aft view

Painting

Finish

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

Flight Test

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

It rains on Friday and Saturday, and I'm hesitant t' fly. Aye aye! Avast! 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, me hearties, arrr, ya bilge rat, which was perfect. Blimey! I was pretty nervous durin' t' countdown, me bucko, ya bilge rat, ya bilge rat, and we had a hold for a low flyin' aircraft, but finally, shiver me timbers, t' moment comes. Begad! Blimey! 5, 4, 3, 2, shiver me timbers, shiver me timbers, 1 ignition. It's away! Great flight! It arced a bit after it left t' rod, ya bilge rat, but very smooth, no sign o' a wobble or instability o' any kind. Arrr! Ahoy! T' ejection fired right at apogee, and Tintinique drifted slowly down, landin' approximately 40" from t' pad. Well, blow me down! Avast, me hearties, 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, ya bilge rat, but I couldn't find t' piece chipped out so it probably happened in t' air. Ya scallywag! Easy t' fix, me bucko, next flight comin' soon...

Nosecone damage