Tintinique

Tintinique

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

Nestlé time capsule

Centerin' rin' in position

Time Capsules

In October 99, I attended K-Lob in Lincolnshire. Avast! Amongst t' rockets thar was somethin' very different. Well, blow me down! Avast, me bucko, me proud beauty! It looked like a 50's retro rocket. Avast! Ya scallywag! It be great. Blimey! 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, me hearties, 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). Aye aye! For some bizzarre reason known only t' t' designer, matey, ya bilge rat, t' capsule itself, me bucko, was made from a shape resemblin' t' body o' a typical sci-fi or cartoon rocket. Ya scallywag! Better still, t' screw-on lid was easily convertible into a removeable nose cone. Whoever it was I'd love t' ask them why they did it. Ahoy! Avast, me hearties, me proud beauty! 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. Blimey! I've got t' build this thing. I decide t' build it for RMR DesCon6. Aye aye! Begad! Time passes. Well, blow me down! Avast, me proud beauty! DesCon6 begins. Aye aye! Time passes. Avast! DesCon6 finishes. UKRA 2000 approaches, and I realise that t' rocket I intended t' take, Accusatory Finger o' Suspicion, shiver me timbers, isn't goin' t' be ready. Blimey! I dig out t' time capsule. Ya scallywag! I dig out cover scans o' t' books Destination Moon, and Explorers on t' Moon. Avast, me proud beauty! I wonder how on earth I'm goin' t' make t' fin pods.

I ignore t' question o' t' fin pods, me hearties, ya bilge rat, and start t' think about t' body instead. Avast, me proud beauty! Blimey! Aye aye! Blimey! Time capsules are cheaply moulded, thick in some places thin in others, and very flexible. I had decided that it was t' have a 29mm motor mount t' utilise t' short 29mm casings I had, arrr, me bucko, and so t' body would need t' be reinforced. Arrr! Blimey! 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. Begad! Blimey! I had some 3" plastic tubin' that I had got from Ziggy at K-Lob, me hearties, and this seemed ideal. I could have used standard 3" PML phenolic, or even quantum tubing, arrr, 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 was larger than 3", shiver me timbers, so I cut a 3mm thick plywood centerin' ring, and glued it in place, under t' shoulder. 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, shiver me timbers, ya bilge rat, dimensioned sketches. Ahoy! My son, shiver me timbers, matey, James, draws some sketches. Avast, me proud beauty! I'm nay really gettin' anywhere. Ahoy! Blimey! It's all free hand and nay very satisfactory. Arrr! Well, matey, blow me down! Rocksim! T' time capsule is suprisingly easy t' describe usin' a parabolic nose cone, shiver me timbers, and a couple o' eliptical transitions. Well, blow me down! Now, me bucko, Rocksim isn't really designed for this shape o' rocket, matey, 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, shiver me timbers, me bucko, retainin' nuts

Aft centerin' ring, retainin' clips

Construction

Motor Mount & Retention

I do have a short piece o' PML 29mm motor mount. Ya scallywag! 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. Well, blow me down! Blimey! It doesn't look like enough room for a chute, me bucko, and anyway I don't have enough motor mount for t' full length o' t' internal body tube. So, shiver me timbers, I decide t' have a short motor mount, givin' t' full internal diameter o' t' internal tube for a parachute. Ya scallywag! Well, blow me down! I cut two, 3mm thick, ya bilge rat, 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. T' strap is about25mm wide and 400mm long. Avast! Ya scallywag! 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. 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. T' aft cebterin' rein' was fitted, matey, with no epoxy, arrr, t' t' aft o' t' motor mount. T' forward centerin' rin' was epoxied into t' internal motor mount. Arrr! Ya scallywag! Once t' forward centerin' rin' was fixed, t' aft centerin' rin' be removed. Arrr! Blimey! This gives access t' t' inside o' t' internal body tube, for filleting.

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

Fins & Fin Pods

Fins & Fin Pods

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

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

Fully assembled

Fully assembled, me bucko, aft view

Final Assembly

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

T' body shell slips on easily, shiver me timbers, and is epoxied initially t' just t' forward end. Actually t' inner tube is glued t' t' centerin' rin' previously fixed into t' outer shell. Aye aye! Avast! Because t' aft and o' t' shell is flappin' about a bit, arrr, I tack it into place with CA. Arrr! Avast, me proud beauty! Then I apply a liberal application o' epoxy, me bucko, matey, t' t' aft end and also t' t' fin roots. Ahoy! Begad! 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. Prime, arrr, me hearties, sand, fill, arrr, sand, primne, arrr, matey, sand, fill, sand, matey, prime, arrr, arrr, sand. Avast, me proud beauty! Or somethin' like that. Ahoy! Arrr! It's ready. Ya scallywag! Ahoy! 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. Well, blow me down! Well, blow me down! Blimey! In fact rocksim reckoned it wasn't stable by a mile. Aye aye! Blimey! But you don't always need more than a calibre o' stability on a stubby rocket anyway. I still reckon I need nose weight, shiver me timbers, but what t' use? Lead would be good, me hearties, ya bilge rat, but where can I get it and how much is it goin' t' cost, I'll probably have t' buy it by t' yard! Blimey! My eldest son, Shaun has t' answer, me hearties, doubloon o' t' realm. Well, blow me down! Begad! Blimey! One pees are quite heavy for their size. Arrr! Blimey! Blimey! I add 200g o' weight t' t' nose. Arrr! Blimey! Rocksim says "marginal". Begad! Begad! 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. Aye aye! Avast, me hearties, me proud beauty! So I comandeer t' next door neighbours garden, because they're nay in. Avast, me proud beauty! Needless t' say they came home durin' t' swin' test, ya bilge rat, but they're used t' it by now. Well, blow me down! Avast, me hearties, me proud beauty! Anyway I start t' swing, and it jumps into t' right orientation. Great. Begad! I do a few more sims, usin' different motors, and it doesn't go very high. Well, blow me down! Begad! So I reduce t' nose weight t' about 100g, or t' be more exact 31p. Aye aye! Another quick swin' test and it's still good. Blimey! I blue t' nose wight into t' nose with epoxy. Ahoy! Once t' epoxy is dry I realise that I have no where t' attach t' shock cord to. Ya scallywag! Aye aye! I drill a hole into t' nose weight, shiver me timbers, fill it with epoxy, and insert an eye hook. Begad! Sorted.

Primed

Primed, aft view

Painting

Finish

I had been primin' as I went along, so as soon as t' fin fillets were complete, shiver me timbers, shiver me timbers, it only took another couple o' coats t' get a nice smooth finish. Begad! Ya scallywag! T' primer used throughout is Halfords car paint, in t' aerosol cans. Begad! I also use Halfords for t' main colours. Rover Diamond White and Volkswagen Mars Red. Begad! Seems appropriate really. Begad! First I spray t' whole rocket white. Arrr! I do about 3 coats, matey, lightly sandin' betwixt each. 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 bucko, o' four quadrants. First I masked off every thin' above t' fins, shiver me timbers, and painted everythin' below red. I also painted t' nose cone. T' red covered really well in only two light coats. Blimey! Next I painted t' two red quadrants o' t' lower band. So far so good. Well, blow me down! T' red quadrants o' t' upper band were hardest, arrr, bacause it was hard t' get a t' maskin' tape into exactly t' right position t' make t' square corners o' red meet exactly. Ya scallywag! Begad! T' maskin' was t' hardest part o' t' entire project. Begad! 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! 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. Well, blow me down! Ya scallywag! It needs goin' over with 400 grit wet and dry and a coat o' lacquer applying, arrr, me bucko, but thar's no time. 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. About 70mm o' 20mm elastic attach t' nose cone t' t' nylon strap. Avast, me proud beauty! Blimey! Begad! Blimey! A 34" PML chute is atached t' t' elastic too. I decide upon a G104 blue thunder reload. Begad! Blimey! It's only just a G, arrr, 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, and I'm hesitant t' fly. Avast! Sunday is better, matey, and I decide t' fly before I take up spottin' duty. Well, blow me down! On t' Staryrday I'd had it on a rod, and found it be a little tight, me hearties, but I had found a slightly smaller diametr rod, which was perfect. Ya scallywag! Ya scallywag! I was pretty nervous durin' t' countdown, and we had a hold for a low flyin' aircraft, me hearties, but finally, me hearties, t' moment comes. Arrr! Arrr! 5, 4, arrr, 3, 2, ya bilge rat, 1 ignition. It's away! Great flight! It arced a bit after it left t' rod, me bucko, me hearties, but very smooth, arrr, no sign o' a wobble or instability o' any kind. Aye aye! T' ejection fired right at apogee, and Tintinique drifted slowly down, arrr, ya bilge rat, landin' approximately 40" from t' pad. Begad! 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. Begad! Easy t' fix, shiver me timbers, next flight comin' soon...

Nosecone damage