Plastic Kit 1/144 Scale Saturn V

Plastic Kit 1/144 Scale Saturn V

Contributed by Darren Longhorn

(Contributed - by Darren J Longhorn - 04/01/04)

Brief:

I wanted t' make somethin' t' fly in t' scale contest at t' IRW 2003, shiver me timbers, and I only had a week t' do it in. Avast, me proud beauty! I be very intrigued by t' recent 10...9...8... article detailin' a Plastic Model Conversion (PMC) by Steven Rogers. Blimey! Lastly, there were two Airfix 1/144th scale Saturn V kits peerin' out o' a bag in the corner o' t' "spare" room. These had been bought several years ago when Woolworth's were sellin' them off for less than a tenner each. Ahoy!

Hmmm, t' theme for t' IRW scale contest changes every year, me bucko, and this year it be "manned boosters", shiver me timbers, matey, so t' Saturn V would fit, arrr, but it also suggested t' Cosmodrome Vostok kit peerin' at me from another corner o' the room. Begad! Ya scallywag! However, that particular kit is rather more than a week's worth of building! For me, anyway. Avast, me proud beauty! So, unless I built somethin' from scratch, that made the Saturn V favourite again. Ya scallywag!

Construction:

There were a few compromises:

  • I had originally bought t' two Saturn V kits with t' intention of buildin' one for display, arrr, with t' possibility o' convertin' one for flight. Avast! Of course, once I started t' think about how I might go about it, me bucko, arrr, me imagination ran wild. Avast, me proud beauty! What motors should it be built for? Naturally, arrr, me first inclination was t' power all three stages: 5 x 18mm in t' S-IC (first stage), 5 x 13mm in the S-II (second stage) and a 13mm motor in t' S-IVB (third stage). Well, ya bilge rat, blow me down! Just as naturally, I discarded this idea when I considered what I would do for fins on the upper stages. Well, blow me down! A bit o' googlin' revealed that this had been done before, but t' foldin' fins mechanisms were beyond me in t' time available.
  • I googled widely and consulted various email lists including pmc-rockets@yahoogroups.com where I found some good advice. Ahoy! Eventually I decided t' keep it simple and go with a single motor mount. Avast! Blimey! That made t' motor mount size a no-brainer too. Arrr! Begad! Blimey! Rocksim be tellin' me that an 18mm motor wouldn't be enough (even a composite D would be borderline) and so it had t' be 24mm. Rocksim also had some interestin' things t' say about t' first stage fins. It was quite easy t' develop a simple model in Rocksim, me hearties, arrr, and it showed that with a little nose weight t' model would be stable even with scale sized fins. Avast! Blimey! You can download a copy o' the Rocksim file here. Begad! However, that additional nose weight would also increase the motor power required. Begad! At this point I still thought thar was a chance o' being able t' fly on an Estes D, ya bilge rat, arrr, so I wanted t' minimise t' weight.
  • Recovery was another issue that need some careful thought. Arrr! Begad! I suppose the obvious thin' t' do would have been t' run a stuffer tube t' full length of the stack and use t' Command & Service Module as t' nose cone. Ahoy! However this would have meant puttin' quite a lot o' work into centerin' t' stuffer tube, arrr, me hearties, so I opted t' split t' model at t' stage 1 / 2 join. Avast! Given that basic design, I thought it best t' recover t' two halves separately on independent parachutes. Arrr! I'll go into t' detailed arrangement later, shiver me timbers, me bucko, suffice t' say that the main work in this conversion is runnin' a motor mount / stuffer tube through t' first stage.

These construction notes should ideally be read in conjunction with the instructions that come with t' kit. A scan is available here. Ahoy! I also submitted this scan t' Sven Ninfinger's web site http://www.ninfinger.org/ some time ago, matey, me hearties, me bucko, so they may have been uploaded and available thar by now. Blimey! Avast! For those unfamiliar with t' Ninfinger site, it's a huge resource coverin' both model rocketry and scale space modelling. In t' followin' paragraphs t' numbers in parenthesis are t' actual part numbers.

Step 1

Add t' conduits t' the fin can, shiver me timbers, but omit t' fins. Ahoy! T' fins from t' kit are nay used, but one is needed t' be used as a template. I used clear 1mm thick Lexan t' make larger replacement fins. Usin' one o' t' original fins I scribed t' outline and painted on t' pattern o' t' original fin. Begad! Ya scallywag! T' new fins had tab matchin' the original fins. Arrr! I found them t' be a tight fit, so simply push fit rather than glued them into place. Ya scallywag! After tryin' them out, I removed them until after final painting. Ahoy!

 

Step 2

Cut off t' mountin' studs from t' booster fin can (5) and t' engine mountin' plate (18). Avast! T' stud can be cut from t' plate with an x-act knife. T' stud on t' fin can may be broken off manually.Cut a hole to suit a BT-50 motor mount tube in both t' fin can and t' plate. Aye aye! Avast! This is for the motor mount/stuffer tube. Well, me bucko, blow me down! Assemble t' outer nozzles as shown and fit to the baseplate, omittin' t' centre nozzle. Avast, me proud beauty! Spray t' nozzle base plate assembly, and t' inside o' t' fin can silver. Well, blow me down! Arrr!

Glue a small wooden block t' t' back o' t' nozzle plate and allow t' dry. Drill a small pilot hole through t' nozzle plate and into t' wooden block. Run some thin CA into t' hole and then screw in a small eye hook. This is the parachute attachment point for recovery o' t' first stage. Ahoy! Don't glue the nozzle plate assembly t' t' fin can yet. Ya scallywag!

Step 3

Spray t' inside o' t' first stage halves silver. Ya scallywag! I used some metallic silver paint from B&Q. Begad! Arrr!

At this point I should admit that I didn't really pay attention t' the colour o' t' innards o' t' stages, arrr, or even t' aft ends and engine bells. Ya scallywag! If I had, I would have noticed that silver isn't really appropriate! You can see what I mean by takin' a look at these photos o' t' Saturn V at KSC - http://www.nsrg.org.uk/outings/ksc/saturn/. I took these pictures when I went t' see t' last Columbia launch in January 2003 - http://www.nsrg.org.uk/outings/ksc/saturn/.

Open up a hole in t' first stage forward tank bulkhead (19) for t' BT50 motor mount. Cut a length o' BT50 310mm long, me hearties, ya bilge rat, matey, this is used for t' motor mount / stuffer tube. Ya scallywag! Us a short piece o' coupler tube, arrr, or a slice o' a spent Estes D motor as a thrust ring. Begad! At this point I should also have added a motor retainin' hook, but I forgot. More o' this later!

Although I chose t' use t' forward tank bulkhead as t' centerin' ring, me hearties, I didn't glue it into t' place directed by t' instructions. Avast, me proud beauty! I put it about mid-way up T' first stage. Begad! This leaves much more room for parachutes. Well, blow me down! T' two halves o' t' first stage (20,21) are then assembled and glued t' t' fin can. Next slide in t' motor mount / stuffer tube, but don't glue it in place yet. Well, me bucko, blow me down! I chose t' paint this before assembly, as it's much easier. Dry fit t' engine mountin' plate and nozzle assembly from step 2. Avast, me proud beauty! This allows accurate positionin' o' t' stuffer tube. Ahoy! Ya scallywag! T' end should be level with t' ends o' the four nozzles. Begad! Carefully remove t' assembly, matey, glue t' stuffer tune in place and replace and fix t' nozzle assembly. Aye aye! Havin' t' motor mount level with t' end of t' rocket nozzles means that they can be left on for flight. Arrr! Just arrange for t' exhaust o' t' real motor t' be deflected away form t' base o' the rocket! Glue on two short lengths o' launch lug, one at t' top o' t' body, one at t' base.

Step 4

Assemble t' interstage as directed and spray t' inside silver. Ya scallywag! Although it's designed t' be removable, I glued t' interstage t' t' first stage because, as with t' location o' t' forward tank bulkhead, it leaves more room for t' parachutes.

Step 5

Open up a hole in t' second stage aft bulkhead (27) t' take a length of BT50 coupler. Aye aye! Cut a length o' BT50 coupler 45mm long. Blimey! Cut a thick card or balsa centerin' rin' 60mm in diameter t' centre t' BT50 coupler. Begad! I used card. Ya scallywag! It doesn't really have t' be very strong, me hearties, it's more o' a guide than anything.

Cut two small block o' wood and glue one t' back o' t' back o' t' aft bulkhead, and one t' inside o' one o' t' body halves. Drill two small pilot holes and screw in eye hooks suin' CA as before. Avast, me proud beauty! It is important t' make sure these hooks will be in line when all t' part are assembled. Ahoy!

Push fit t' engine nozzles onto t' aft bulkhead, me bucko, but don't glue yet. Blimey! Begad! Stand the part on t' nozzles, and insert t' length o' BT50 coupler into t' hole in the bulkhead, but don't glue it in place yet. Avast! Slip t' centerin' rin' over the coupler and T' within t' forward part o' T' bulkhead, shiver me timbers, makin' sure that the end o' t' coupler is square with t' ends o' t' motor nozzles. Avast, me proud beauty! Glue the centrin' rin' into part 27. Let it dry. Blimey!

Cut a small bulkhead from balsa or thick card and use it t' plug t' end of the coupler. T' protrudin' length o' coupler will fit into t' BT50 stuffer tube on t' first stage. Avast, me proud beauty! Assemble t' rest o' t' second stage as directed, shiver me timbers, but omittin' t' centre motor nozzle and it's mountin' (26,30,31). Arrr! With a sharp knife, matey, Remove t' small studs in t' inside o' t' base o' t' second stage body. Ahoy! These are meant t' "twist lock" t' second stage t' t' first stage, me bucko, matey, but as this is where t' rocket will split at ejection, this would now be a Bad Thin' (TM). Aye aye!

Step 6

Assemble t' third stage as directed, shiver me timbers, but omit t' engine nozzle as it won't be visible. Arrr! Begad! Glue this stage t' t' second stage after painting. Begad!

Step 7

Skipped assembly o' t' Lunar Module as it won't be visible in t' completed model. Begad! Well, blow me down!

Step 8

Omit t' Lunar Module from step 7 and glue t' adapter rin' (61) and LM shrouds (62, matey, 63) in place. Arrr! I didn't bother t' paint t' interiors, me bucko, me hearties, as they are not visible when glued in place. Begad!

Step 9

Build t' Service Module as indicated, me hearties, but you can omit t' nozzle (68) as it isn't visible when t' model is completed. Although it is designed t' be removed, me bucko, matey, ya bilge rat, I glued t' service module t' t' LM housing, after final paintin' to avoid losin' it. Ahoy! Blimey!

Step 10

Stage 10 be t' assembly o' t' command module. Since t' command module isn't visible when assembled, arrr, this stage can be omitted entirely.

Step 11

Complete stage 11 as directed, apart from t' command module that wasn't built in stage 10, paint t' assembly white and glue t' boost protective cover to t' service module. Ahoy! Begad!

Step 12

Omit t' nozzle adapter (79), instead glue a spent 24mm motor t' t' stand. This will fit into t' BT50 tube o' t' motor mount and allow display o' the completed model. Ya scallywag! Ya scallywag!

Finishing:

Some o' t' paintin' I did as I went along, but I left t' final painting until most stuff be assembled. Ahoy! I masked off t' insides o' t' first, second and third stages, ya bilge rat, usin' rolled up paper. Ya scallywag! Blimey! I painted them all over usin' a couple of coats o' Halford Diamond White. Well, blow me down! T' plastic seemed like a good surface, ya bilge rat, me hearties, so I skipped applyin' a coat o' primer.

I did consider maskin' around t' black roll patterns and sprayin' them on too, matey, matey, but I always find maskin' t' be a little tricky, shiver me timbers, and fittin' t' tape to the surface corrugations was a bit daunting.

In t' end I used a paintbrush and Humbrol Satin Black enamel. Avast! Blimey! OK, matey, so up close you can tell I applied t' paint by hand, but from a distance I reckon it looks acceptable. Avast! Blimey!

Of course I discarded t' Airfix paintin' directions, me bucko, as they are for a test article rather than any o' t' manned boosters. Ahoy! Everyone knows that, shiver me timbers, right? So I took me paintin' directions from Peter Alway's excellent "Rockets o' the World" (ISBN 0-9627876-7-1 - a must for every Space Modeler's book shelf). Havin' said that, me hearties, I did cheat a little. Avast, me proud beauty! Ya scallywag! Because I was applyin' t' paint by hand, me bucko, I decided t' take liberties with t' positionin' o' some o' the black/white painted edges t' places more convenient for me agin' Mk1 eyeballs. I leave determination o' t' location o' these liberties as an exercise for the reader.

Decals

T' Airfix decals are OK, arrr, in t' main, with a couple o' exceptions. T' red decals, me hearties, "USA" & "UNITED STATES" are fine, as are the black & white fin letters and targets, but t' Stars & Stripes are terrible. T' blue and white star field is out o' register with t' red and white stripes. Avast! I fixed this by cuttin' out t' star fields and applyin' them separately. Aye aye! T' same problem occurs on t' much smaller Stars and Stripes for the Service module. Blimey! Begad! Havin' got this gripe over, I have t' admit that t' decals were nice and thin and conformed well when applied t' raised detail. Blimey!

Recovery Rigging

Parachutes. Blimey! I love hemispherical parachutes and loved t' idea o' me rocket droppin' from t' sky on proper red & white parachutes. There are several tool on t' internet for generatin' templates for t' gores. Ahoy! I used t' one on Richard Nakka's experimental rocketry web site. Aye aye! This generates pattern to produces a semi-ellipsoid shape, which looks like a slightly flattened hemisphere. It's meant t' be more efficient, but I would guess it's hard to tell at these dimensions. Ahoy! Avast! I made both parachute with gores 250mm across the bottom, with six gores per parachute. Begad! T' gores were cut from nylon, ya bilge rat, and my ever support full wife, me bucko, shiver me timbers, Karen, me bucko, me hearties, stitched them together for me.

T' parachutes are both housed inside t' first stage. T' first stage parachute within T' stuffer tube, and t' parachute for t' second/third stage assemble around t' outside o' t' stuffer tube. Ya scallywag!

My original idea be t' have separate parachutes for t' first stage, and t' rest o' t' rocket, rigged t' bring them down horizontally. Begad! Avast, me proud beauty! That is exactly what I did for t' second/third stage/CSM assembly. Ahoy! Aye aye! I attached a length o' Keelhaul®©™ approximately 600mm long to the previously installed eye hooks. Avast! Holdin' t' model up by t' Keelhaul®©™ I arranged for t' rocket half t' be suspended horizontally, and tied a loop where I was holdin' t' Keelhaul®©™. Avast! This is thar t' parachute shroud lines were attached to. Arrr!

For t' first stage, I started havin' second thoughts. I only had one solid parachute attachment point, me bucko, at t' base for t' stage. Arrr! T' intention had been to have another attachment point inside t' stuffer tube. Avast! Aye aye! However t' stuffer tube is unsupported for 110mm o' it's length, matey, and it seemed likely that this would crimp when hangin' from t' parachute. I tried t' rectify this by fitting a "fillet" o' balsa betwixt T' body wall and stuffer tube, changing the surroundin' space from an "O" shape t' a "C" shape, me hearties, ya bilge rat, but I still wasn't satisfied. In t' end I reasoned that this stage needn't be recovered horizontally as all o' t' fragile detail was at t' aft end. Blimey! Avast! So, shiver me timbers, I used a single parachute attachment point, matey, runnin' a length o' Keelhaul®©™ up the side o' t' rocket and into t' parachute bay via a small notch in t' stage body.

Flight:

It was when preppin' T' rocket for flight that I realised I had left off any method o' motor retention. Avast! Avast, shiver me timbers, me proud beauty! Blimey! I could have sworn that I had fitted and engine hook, me bucko, but alas, me bucko, no. As launch fever gripped me, I casually applied some tape around t' end o' t' RMS. Aye aye! Begad! Blimey! It's hard t' believe that I really thought this would be sufficient. It wasn't. Arrr!

T' launch was excellent, with a reasonably straight boost, but thar be no ejection at apogee. It looked like we were goin' t' see a classic lawn dart, but t' rocket became horizontal and began t' spin. Begad! Aye aye! I've seen rockets recover like this before, arrr, notably t' Estes Phoenix. Blimey! Blimey! Upon examination, it was seen that the motor had nay been retained and had in fact been kicked out at ejection. Lots o' people helped search for t' RMS casing, matey, randomly at first, matey, but then I think it was Mike Crewe who suggested formin' a line and walkin' t' area methodically. I think John Bonsor was t' one t' find t' casing. Avast! Many thanks to Mike, arrr, John and everyone else that helped with t' search.

T' rocket itself was in surprisingly good condition. Avast! All four fins had come off, as had t' Escape Tower and t' third stage, but it was all repairable. Ya scallywag! I just need t' retrofit some positive motor retention and I'll be ready t' fly again.

As for t' contest, matey, arrr, well, despite t' damage, shiver me timbers, I won joint first prize, shared with Mike Crewe and his Estes Mercury Redstone. Ya scallywag! We both won Estes Big Bertha rocket kits, which we're goin' t' drag race at next year's event. Begad!

Summary:

A very slightly different version o' this article be published in volume 7 issue 4 o' 10...9...8... Begad! t' newsletter o' t' United Kingdom Rocketry Association. Arrr!

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