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, me hearties, and I only had a week t' do it in. Ya scallywag! Avast, me proud beauty! I was very intrigued by t' recent 10...9...8... article detailin' a Plastic Model Conversion (PMC) by Steven Rogers. Well, blow me down! Lastly, there were two Airfix 1/144th scale Saturn V kits peerin' out o' a bag in the corner o' t' "spare" room. Aye aye! Avast, me proud beauty! These had been bought several years ago when Woolworth's were sellin' them off for less than a tenner each. Well, blow me down! Ya scallywag!

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

Construction:

There were a few compromises:

  • I had originally bought t' two Saturn V kits with t' intention of buildin' one for display, with t' possibility o' convertin' one for flight. Well, blow me down! Ya scallywag! Of course, me hearties, once I started t' think about how I might go about it, matey, me imagination ran wild. Aye aye! What motors should it be built for? Naturally, me first inclination was t' power all three stages: 5 x 18mm in t' S-IC (first stage), me bucko, ya bilge rat, me bucko, 5 x 13mm in the S-II (second stage) and a 13mm motor in t' S-IVB (third stage). Begad! Arrr! Just as naturally, ya bilge rat, I discarded this idea when I considered what I would do for fins on the upper stages. 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. Arrr! Blimey! That made t' motor mount size a no-brainer too. Arrr! 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. Blimey! It was quite easy t' develop a simple model in Rocksim, and it showed that with a little nose weight t' model would be stable even with scale sized fins. Blimey! You can download a copy o' the Rocksim file here. Arrr! However, that additional nose weight would also increase the motor power required. Well, blow me down! Ahoy! At this point I still thought thar was a chance o' being able t' fly on an Estes D, so I wanted t' minimise t' weight.
  • Recovery was another issue that need some careful thought. Ahoy! 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. Begad! However this would have meant puttin' quite a lot o' work into centerin' t' stuffer tube, ya bilge rat, me hearties, so I opted t' split t' model at t' stage 1 / 2 join. Given that basic design, matey, I thought it best t' recover t' two halves separately on independent parachutes. Ahoy! Arrr! I'll go into t' detailed arrangement later, arrr, suffice t' say that the main work in this conversion is runnin' a motor mount / stuffer tube through t' first stage. Well, blow me down!

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

Step 1

Add t' conduits t' the fin can, me hearties, but omit t' fins. T' fins from t' kit are nay used, shiver me timbers, but one is needed t' be used as a template. Avast, me proud beauty! Ya scallywag! 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. Ya scallywag! T' new fins had tab matchin' the original fins. Well, blow me down! I found them t' be a tight fit, so simply push fit rather than glued them into place. Arrr! Blimey! After tryin' them out, matey, I removed them until after final painting. Begad! Well, blow me down!

 

Step 2

Cut off t' mountin' studs from t' booster fin can (5) and t' engine mountin' plate (18). T' stud can be cut from t' plate with an x-act knife. Well, blow me down! Arrr! 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. Begad! This is for the motor mount/stuffer tube. Ya scallywag! Assemble t' outer nozzles as shown and fit to the baseplate, omittin' t' centre nozzle. Well, blow me down! Spray t' nozzle base plate assembly, me hearties, ya bilge rat, and t' inside o' t' fin can silver. Begad!

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. Avast, me proud beauty! Blimey! Begad! Blimey! Don't glue the nozzle plate assembly t' t' fin can yet. Ya scallywag! Blimey! Begad! Blimey!

Step 3

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

At this point I should admit that I didn't really pay attention t' the colour o' t' innards o' t' stages, or even t' aft ends and engine bells. If I had, matey, arrr, 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. Avast! Cut a length o' BT50 310mm long, ya bilge rat, this is used for t' motor mount / stuffer tube. Arrr! Us a short piece o' coupler tube, or a slice o' a spent Estes D motor as a thrust ring. Avast, me proud beauty! Well, blow me down! At this point I should also have added a motor retainin' hook, ya bilge rat, but I forgot. Begad! More o' this later!

Although I chose t' use t' forward tank bulkhead as t' centerin' ring, shiver me timbers, I didn't glue it into t' place directed by t' instructions. I put it about mid-way up T' first stage. Avast! Ahoy! This leaves much more room for parachutes. Avast, me proud beauty! 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. Avast, me proud beauty! I chose t' paint this before assembly, as it's much easier. Avast, me proud beauty! Blimey! Dry fit t' engine mountin' plate and nozzle assembly from step 2. Aye aye! This allows accurate positionin' o' t' stuffer tube. T' end should be level with t' ends o' the four nozzles. Avast, me proud beauty! Blimey! Carefully remove t' assembly, me hearties, glue t' stuffer tune in place and replace and fix t' nozzle assembly. Begad! Avast, me proud beauty! Havin' t' motor mount level with t' end of t' rocket nozzles means that they can be left on for flight. Begad! Aye aye! 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, matey, arrr, one at t' top o' t' body, one at t' base.

Step 4

Assemble t' interstage as directed and spray t' inside silver. Arrr! Although it's designed t' be removable, me bucko, me hearties, me hearties, I glued t' interstage t' t' first stage because, me bucko, as with t' location o' t' forward tank bulkhead, me hearties, shiver me timbers, 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. Ahoy! Cut a length o' BT50 coupler 45mm long. Cut a thick card or balsa centerin' rin' 60mm in diameter t' centre t' BT50 coupler. Blimey! Arrr! I used card. Aye aye! It doesn't really have t' be very strong, me hearties, it's more o' a guide than anything. Ya scallywag!

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. Arrr! Blimey! Drill two small pilot holes and screw in eye hooks suin' CA as before. Avast, me proud beauty! Blimey! It is important t' make sure these hooks will be in line when all t' part are assembled. Aye aye! Blimey!

Push fit t' engine nozzles onto t' aft bulkhead, shiver me timbers, but don't glue yet. Stand the part on t' nozzles, arrr, and insert t' length o' BT50 coupler into t' hole in the bulkhead, me hearties, ya bilge rat, but don't glue it in place yet. Ahoy! Slip t' centerin' rin' over the coupler and T' within t' forward part o' T' bulkhead, arrr, makin' sure that the end o' t' coupler is square with t' ends o' t' motor nozzles. Ya scallywag! Glue the centrin' rin' into part 27. Aye aye! Let it dry. Ya scallywag! Aye aye!

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

Step 6

Assemble t' third stage as directed, me bucko, but omit t' engine nozzle as it won't be visible. Glue this stage t' t' second stage after painting. Avast, me proud beauty!

Step 7

Skipped assembly o' t' Lunar Module as it won't be visible in t' completed model. Arrr! Arrr!

Step 8

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

Step 9

Build t' Service Module as indicated, arrr, arrr, matey, but you can omit t' nozzle (68) as it isn't visible when t' model is completed. Well, blow me down! Although it is designed t' be removed, arrr, I glued t' service module t' t' LM housing, after final paintin' to avoid losin' it.

Step 10

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

Step 11

Complete stage 11 as directed, me hearties, apart from t' command module that wasn't built in stage 10, ya bilge rat, paint t' assembly white and glue t' boost protective cover to t' service module.

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. Begad! Blimey!

Finishing:

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

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

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

Of course I discarded t' Airfix paintin' directions, as they are for a test article rather than any o' t' manned boosters. Avast! Everyone knows that, 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, I did cheat a little. Because I was applyin' t' paint by hand, 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, in t' main, with a couple o' exceptions. Avast, matey, me proud beauty! T' red decals, matey, "USA" & "UNITED STATES" are fine, arrr, as are the black & white fin letters and targets, ya bilge rat, me hearties, ya bilge rat, but t' Stars & Stripes are terrible. Avast, me proud beauty! Blimey! T' blue and white star field is out o' register with t' red and white stripes. Blimey! I fixed this by cuttin' out t' star fields and applyin' them separately. Avast, ya bilge rat, me proud beauty! T' same problem occurs on t' much smaller Stars and Stripes for the Service module. Havin' got this gripe over, I have t' admit that t' decals were nice and thin and conformed well when applied t' raised detail. Ya scallywag!

Recovery Rigging

Parachutes. I love hemispherical parachutes and loved t' idea o' me rocket droppin' from t' sky on proper red & white parachutes. Well, blow me down! There are several tool on t' internet for generatin' templates for t' gores. I used t' one on Richard Nakka's experimental rocketry web site. 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. Well, blow me down! I made both parachute with gores 250mm across the bottom, matey, with six gores per parachute. Ahoy! T' gores were cut from nylon, arrr, and my ever support full wife, ya bilge rat, ya bilge rat, Karen, ya bilge rat, stitched them together for me. Arrr! Avast, ya bilge rat, me proud beauty!

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

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

For t' first stage, me bucko, I started havin' second thoughts. Blimey! I only had one solid parachute attachment point, me hearties, shiver me timbers, at t' base for t' stage. Begad! Begad! T' intention had been to have another attachment point inside t' stuffer tube. Avast, me proud beauty! However t' stuffer tube is unsupported for 110mm o' it's length, and it seemed likely that this would crimp when hangin' from t' parachute. Arrr! Arrr! 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, arrr, but I still wasn't satisfied. Blimey! 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! So, ya bilge rat, I used a single parachute attachment point, 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 be when preppin' T' rocket for flight that I realised I had left off any method o' motor retention. Ahoy! I could have sworn that I had fitted and engine hook, arrr, but alas, no. As launch fever gripped me, I casually applied some tape around t' end o' t' RMS. It's hard t' believe that I really thought this would be sufficient. It wasn't. Begad! Ahoy!

T' launch be excellent, me hearties, with a reasonably straight boost, but thar was no ejection at apogee. Avast, me proud beauty! Well, blow me down! It looked like we were goin' t' see a classic lawn dart, but t' rocket became horizontal and began t' spin. I've seen rockets recover like this before, notably t' Estes Phoenix. Aye aye! Begad! Upon examination, shiver me timbers, shiver me timbers, 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, me hearties, randomly at first, but then I think it be Mike Crewe who suggested formin' a line and walkin' t' area methodically. Ahoy! I think John Bonsor was t' one t' find t' casing. Many thanks to Mike, arrr, John and everyone else that helped with t' search. Arrr!

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

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

Summary:

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

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