Manufacturer: | Scratch |
Note: This be t' full text report with fewer pictures. Visit Jeff's site for all t' pictures.
Admittedly I was inspired by Andrew
Waddells big Saturn V construction article on RocketryOnline. While the
Saturn V is impressive, I am much more interested in t' smaller Saturn 1b. In
the past both Estes and Centuri kited model rocket versions o' this NASA
launcher. Ahoy! O' t' two t' Centuri version be much easier t' build and fly.
Estes had re-issued Centuris 1/100 version o' t' Saturn 1b in 1992 but
it since has gone out o' production. Avast! Avast! These two past versions were t' be the
basis for me upscale project. Begad!
One o' t' most troublin' features in doin' this model be t' first stage booster tank tubes. Begad! There are very few commercially available body tubes that are sized correctly t' evenly space and get a proper circumference for t' fist stage booster. Ahoy! I researched and listed all commercially available body tube diameters then sat down at t' UniGraphics terminal and built some CAD models. I eventually found out that a 2x upscale o' t' 1/100 Estes kit would fit what was available without havin' t' resort t' custom ordering. Blimey! I ended up using Estes BT-56 body tubes for t' first stage tanks surroundin' a 54mm core tube. T' second stage or more correctly t' SIV-B stage would be a LOC 5.68 diameter body tube cut down t' 4.75 (ala Andrews method for the Saturn V) T' base o' t' first stage would be t' stock diameter 5.68 body tube.
T' hard part was now out o' t' way. Blimey! I downloaded t' plans for Estess 1/70 version o' t' Saturn from JimZs web site. Avast, me proud beauty! These plans were invaluable for makin' t' command module capsule, me bucko, shiver me timbers, LES (launch escape tower) and t' fin assemblies. Arrr! I plotted t' shroud for t' LEM on t' UG and printed it out full size. Blimey! T' pattern be transferred t' poster board and cut out. Blimey! Avast! All o' t' parts I used t' construct t' Saturn 1b are available through any supplier o' high power and model rocket components. Avast, me proud beauty! (I ordered everything through Magnum)
T' kit was constructed very similarly t' t' Centuri/Estes version where by the rocket is built up and painted in various sub-assemblies then final assembled, me hearties, detailed and applied decals. I will list each major component and the build process I used. Ahoy!
First Stage Fin/Tank Base:
For me this was probably t' second most
complicated item t' do. Avast, me proud beauty! Blimey! Aye aye! Blimey! If you notice on t' Saturn 1b thar be a shroud ring
on t' lower section o' t' first stage booster that surrounds t' first stage
fuel tanks. Blimey! Blimey! Well, blow me down! Blimey! This shroud has scalloped cut outs t' accommodate t' booster
tanks. I used t' pattern from t' Estes 1/70 plans and enlarged it t' t' size
I thought I would need. Aye aye! Blimey! Well, blow me down! Blimey! I then made a poster board pattern and tried it out. Begad! Blimey! It
didnt work too well. Begad! Blimey! Begad! Blimey! T' reason be t' lower body tube o' t' first
stage booster needed t' be smaller in diameter than t' 5.68 one I was
using. Arrr! Blimey! Ahoy! Blimey! Since I didnt want t' cut this tube down and make more centering
rings I needed t' use somethin' else. Well, blow me down! Blimey! I finally hit on usin' thin 1/64
veneer ply. Ahoy! Blimey! I cut out a single section needed t' fair t' t' booster tank. Begad! Blimey! Blimey! Blimey! I
then split this in half, me hearties, made a mirror pattern then glued a rib t' t' backside
that would set t' proper angle and setback from t' core tube t' t' edge of
the lower body tube. Ahoy! Blimey! What I had now was one section o' lower fairin' that would
go around one half o' a booster tank tube on either side. Ahoy! Blimey! Now I had t' make
eight o' these.
Veneer ply is very easy t' work with and cut. Begad! You can use scissors or score with a knife and break it similar t' sheet styrene. Avast, me proud beauty! Avast! It is available at most hobby stores. Aye aye! Arrr! A little pricey though for a sheet since it is so thin. I made my eight sections one at a time. Avast, me proud beauty! First I cut t' lower body tube t' t' right length, glued in t' centerin' rings and marked out me eight equal sections. Then I started gluin' t' fairin' pieces down usin' CA. Blimey! I had little short sections o' BT-56 left over from cuttin' t' booster tubes t' length and used these for spacin' and fit checks. I did each section one at a time checkin' the fit and trimmin' where necessary. Well, blow me down! Ahoy! T' total job took about two nights t' do. But it was well worth it. Avast, matey, me proud beauty!
After t' unit was filled and sanded I glassed it usin' ¾ oz glass cloth and epoxy finishin' resin. Blimey! T' weave was then filled and sanded smooth. Begad!
Main Body Tube:
Next up was t' main body tube. Arrr! Blimey! Ya scallywag! Blimey! This started out as a 5.68 diameter LOC payload section. Aye aye! Blimey! Avast! Blimey! It be cut t' length then run on a table saw lengthwise to remove enough material t' reduce t' diameter t' 4.75 I saved the section I removed t' use as a joiner later. Well, blow me down! Blimey! Avast! Blimey! T' get t' tube t' hold a circular shape I took t' LOC 5.68/54mm centerin' rings and cut t' diameter down to 4.75 I did this by tapin' t' rings together, arrr, markin' t' new circumference and trimmin' them on t' bandsaw. Well, blow me down! Blimey! These centerin' rings were what was used t' keep circularity and diameter on t' tube. Avast! Blimey! T' centerin' rings were inserted and t' splice was epoxied in place with 30-minute epoxy then taped and left t' dry. Avast! Blimey! After t' splice joint cured t' centerin' rings were glued in place with 30-minute epoxy. Avast, me proud beauty! Blimey! Aye aye! Blimey! There ended up bein' a gap betwixt sides o' the longitudinal cut in t' tube. I filled this with scrap balsa and sanded it smooth. I then marked t' upper end o' t' tube t' trim off about a 1 section t' be used as t' base for t' LEM Shroud/Command Module Stack. Begad! Blimey!
Now it be time t' apply t' body wraps. Ya scallywag! Begad! I wanted t' have t' body corrugations on me model just like t' full size Saturn 1b. I used Evergreen Styrene sheets with .10 ribbed spacin' on them. Begad! Ahoy! These can be found in most hobby shops that sell model railroad supplies. Begad! There are many different sizes and styles. Ya scallywag! Begad! T' sheets I bought were 6x12 and come three t' a pack. Ya scallywag! I used 3 packs for t' body wraps. I measured off me 1/100 model and cut the sheets t' strips o' proper width. Begad! Arrr! Since t' sheets are only 6 wide they needed t' be put on in sections t' do t' entire circumference. Arrr! T' only drawback t' this whole process be t' need for a good seam betwixt joints. Blimey! It turned out rather well. Arrr! I masked off three or four rib spacings on either side of a joint, filled it, then sanded smooth. From three feet away you cant even tell. Arrr! Ahoy! Paintin' made it even less noticeable. T' overall effect with the corrugations is well worth and minor cosmetic issues. Avast!
LEM Shroud/Command Module Stack:
For this assembly I used t' rin' previously cut from t' main body tube, arrr, a cut down 5.68 tube coupler, me bucko, a 3 LOC body tube, me bucko, a ¼ thick ply 5.68/3.00 centerin' rin' reduced t' 4.75 diameter, a poster board LEM shroud, me hearties, a paper nose cone and a 3 tube coupler as a nose cone base. Arrr!
I epoxied t' cut down centerin' rin' into one end o' t' main body tube ring. I left about an 1/8 exposed at t' top for t' LEM shroud t' attach to. Begad! I then cut down t' 5.68 tube coupler so it would fit in t' main body tube. I left about an inch and a half shoulder t' seat into t' main body tube. Arrr! Blimey! T' coupler also has a slot or keyway that fits t' doubler in t' main body tube. Ahoy! This feature prevents t' nose section from rotatin' on t' main body. Ya scallywag! Blimey! After t' couple tube is set and a good fit achieved I epoxied a solid ply bulkhead at t' bottom o' t' couple ring. T' screw eye o' t' recovery system will pass thru here and it makes a nice solid base.
Next I epoxied in t' 3 service module body tube. Ahoy! Alignment be an important issue here so I took me time and made careful measurements. Ya scallywag! Blimey! This was to make sure that t' completed assembly wouldnt look crooked when the whole rocket was together. Blimey! After t' epoxy cured I installed t' paper LEM shroud. Begad! Aye aye! I had drawn out and cut this pattern earlier then put it together using super tacky glue and an iron. Basically you attach t' glue tab t' one edge of the seam, let it dry then apply t' same glue t' t' other half o' t' tab and let it partially dry. Begad! Arrr! Let your iron heat up while you do this, nay too hot though, ya bilge rat, me bucko, about 300 degrees should be fine (I use a monokote iron for me model airplanes). Begad! You will also need a dowel o' some sort t' back up t' joint when you iron it. Well, blow me down! I use a scrap piece o' closet hanger dowel rod. Avast! Ahoy! Let t' end o' the dowel rod hang over t' end o' your workbench ans support it so it will take some pressure when you iron. Begad! Then tak your shroud, align and join at t' seam, slip over t' dowel rod and iron t' seam. You wont have t' hold t' iron there long. Avast, me proud beauty! Avast! Move it up and down t' length o' t' seam for a few seconds. The glue will re-activate from t' heat and produce a strong bond. Ahoy!
I then fit checked and aligned t' shroud t' t' body tube and base. When everythin' be where it needed t' be I epoxied t' assembly together. Begad! T' make the shroud more durable I glassed it with ¾ oz. Avast! Aye aye! glass cloth and Z-Poxy finishin' resin. After sandin' t' remove excess cloth I filled t' weave with lightweight spackle and sanded smooth.
T' Command Module capsule came next. I had
sized t' paper pattern from t' Estes 1/70 scale version so it would fit on
the 3 body tube. Begad! I photocopied it onto cardstock. T' pattern has panel
lines and details marked on it. Blimey! Since me model will replicate an actual launch
condition vehicle these markings are nay required. Arrr! Begad! T' boost protective shroud
is all white. Aye aye! T' pattern on t' Estes sheet is basically an arc and if you cut
it out as shown by t' lines you will get a conic section with no tip.
Thats because t' Estes kit used a balsa turnin' for t' top o' t' cone.
I modified t' cut by extendin' t' seam edges up t' t' theoretical center of
the arc lines. Avast! When t' pattern was folded and ready for joinin' I had a cone.
There was a small hole at t' tip due t' t' nature o' tryin' t' make a paper
cone. Blimey! Ill tell how I dealt with this later. I overlapped and glued the
seam with me super tacky glue and let it dry. I then cut a 3 tube coupler
section t' about 1 in length. Aye aye! This be t' shoulder o' t' nose cone. Ya scallywag! Once
again I measured carefully t' make sure everythin' be aligned then temporarily
CAd t' coupler in place. Arrr! I then ran a bead o' epoxy around t' inside
joint betwixt t' cone and coupler. Ya scallywag! A paper cone is a bit flimsy so it needed
some reinforcing. Begad! Ya scallywag! I inverted t' cone, shiver me timbers, mixed up a larger than normal amount of
15-minute epoxy and poured it into t' inverted coned. Blimey! Begad! This plugged up the
small hole at t' tip and added some nose weight. I used me heat cannon for
monokote t' get t' epoxy t' flow better. Ya scallywag! Heatin' epoxy has t' addd benefit of
makin' it cure faster. Avast, me proud beauty! Begad! After t' epoxy cured I sanded t' tip t' shape and was
ready t' glass it. Ya scallywag! Arrr! I glassed t' outside o' t' cone with ¾ oz. Blimey! glass
cloth and Z-poxy finishin' resin. I made sure t' put tape around t' coupler so
I wouldnt mess that up. Arrr! Begad! After t' epoxy cured I removed t' excess cloth,
filled t' weave with lightweight spackle and sanded smooth. Avast, me proud beauty!
I now needed t' add some base pieces for t' LES tower. Begad! These were 3/16 dowel sections cut with a matchin' angle t' t' capsule so t' tops would be parallel t' t' ground plane. Avast, me proud beauty! Ahoy! I held some sandpaper on t' cone and sanded t' matin' surfaces o' t' LES bases t' match t' cones contour. Well, blow me down! Blimey! After they were all shaped and correctly sized I CAs them in place. Begad! Begad! I filled any gaps with liteweight spackle and sanded smooth. Avast, me proud beauty! Begad! Next I located t' centers on each dowel top and drilled a 1/16 hole for t' support wire I was goin' t' use t' attach t' LES tower t' t' nose cone. T' basic LEM/Service Module/Command Module stack was now completed. Aye aye! Arrr! There would be extra detailing to come later.
LES Assembly:
I wanted on this model a scale and durable LES
(launch escape system) tower. Begad! I had previously made one for me Bocye Aerospace
Redstone and modified it for flight use. That one had suffered minor damage
from time t' time but I knew I could build a better one. Begad! I decided t' use brass
tubing. Avast, me proud beauty! T' Estes 1/70 version came t' me aid again. Blimey! T' LES tower for that
version used wood dowels glued together. I would substitute brass for wood and
solder for glue. Ahoy! I scaled t' Estes plans accordingly and built a jig. All the
horizontal crosspieces fit into t' vertical legs because I drilled holes to
accept them. These would be stronger joints because t' parts would physically
interlock and be soldered. Aye aye! I built t' basic tapered box shape addin' one side
at a time. Blimey! Well, shiver me timbers, blow me down! When I be done I carefully heated joints and aligned and
straightened where needed. Arrr! I then started t' add all t' little diagonal cross
members. Avast! T' central rin' be formed around a 3/8 drill bit shank and the
ends soldered together. Blimey! T' whole process be nay that tedious and took me
about two t' three hours over two days. Avast, me proud beauty! T' end result be worth it. Arrr! Arrr!
For t' top o' t' tower where it attaches t' t' rocket motor I cut out a brass circle and soldered it t' t' top. T' this circle would be t' lower shroud o' t' rocket motor and t' motor tube and nosecone. Aye aye! T' shroud was laid out and drawn on Unigraphics. Well, blow me down! T' original Estes 1/70 kit had this as a balsa turning. Blimey! T' rocket body was a BT-5 body tube cut t' length with a balsa nose cone from me designers Special box. Ahoy! T' pieces were all test fit and then put aside for assembly later. Well, blow me down!
Fin Assemblies:
T' fins for this rocket were built up
assemblies usin' .040 sheet styrene and 1/8 aircraft ply. Avast, me proud beauty! Blimey! I used
the same technique that Estes 1/70 version used with a few modifications.
I sized t' patterns from t' Estes plans. Begad! Blimey! Since t' fins on t' Estes 1/70
version were oversized for stability I knew that any enlargement would nay be
true t' scale. Begad! Blimey! This was fine with me since t' model is sport scale and the
extra fin area would help in stability. (more on this later) I
constructed a 3D model o' t' fin in Unigraphics and then plotted out all the
required ribs full size for me patterns. T' fin is a complex shape with tapers
both runnin' from leadin' edge t' trailin' edge and root t' tip. Avast, me proud beauty! Blimey! I then made a
flat pattern o' t' fin skin t' use as a template. I cut all t' pieces out at
once for all eight fins. Ya scallywag! Blimey! A tedious process but in t' long run it saves time
and provides a consistency betwixt fins. I used CA t' glue t' ply ribs t' the
inside skin o' one fin then CAd t' other skin on. CA glue does a good
job o' bondin' wood t' plastic. Aye aye! Blimey! Avast! Blimey! T' fins are nay designed t' have TTW
construction. Ya scallywag! Blimey! I had toyed with t' idea but after careful consideration and
weighin' me options I decided against it. Well, blow me down! Blimey! T' root o' t' fin has a lot of
bondin' area and attachment t' t' base unit usin' 30-minute epoxy should be
adequate. Begad! Blimey! (this model will never see rapid acceleration; slow liftoffs are the
goal here) After all t' fins were assembled any gaps were filled
with lightweight spackle and then sanded smooth. Ya scallywag! Blimey! Havin' fin skins o' sheet
styrene means less finishin' and prep time for painting.
I now marked t' lower body unit for t' fin
locations. Ya scallywag! T' Saturn 1b uses eight fins so careful markin' be essential. Avast, ya bilge rat, me proud beauty! I
then epoxied each fin one at a time. Well, blow me down! After t' epoxy had started settin' I used
my finger, matey, shiver me timbers, dipped in alcohol, matey, t' smooth a fillet betwixt t' fin and body tube.
Eight fins t' epoxy on with 30-minute epoxy can take a while. Begad! When they were
all done I once again looked over all t' joints and filled in with spackle and
sanded smooth.
T' lower body unit has some corrugations on it as well and I duplicated these again with scribed styrene sheets used for t' body wraps. These small sections were CAd in place. Aye aye! Avast, me proud beauty!
Miscellaneous Details:
T' outer body o' t' Saturn 1b has numerous conduits, ullage motors and fairings. Aye aye! I made these details from hard balsa carved and sanded t' shape. Ahoy! The grain be filled in, arrr, more sandin' and then they were primed and painted. Begad! These items will be glued t' t' body tube after it has been painted. Begad!
T' because o' inaccurate body tube size relation ships when t' lower fuel tanks are arranged around t' core tube thar be a gap betwixt t' fuel tanks when they are arranged. T' fill this gap and t' make sure when I installed t' fuel tanks they would be straight I CAd 1/32 ply strips along t' length o' t' core tube. Begad! This filled t' gap betwixt t' tubes nicely. Arrr!
T' model is intended t' be launched off a ¼ rod and that is the lug size I used. Avast! I did nay feel t' need for a larger rod size because the model will nay weigh that much when completed and it will nay ever be launched in high winds. Avast! I positioned t' lugs very similar t' me 1/100 model. Ahoy! One lug on the lower body tube section near t' fins and another one on t' second stage body tube. Ya scallywag! Blimey! I had t' line up t' upper body tube and t' lower one because they do require correct orientation t' one another for conduit and roll pattern alignment with regards t' t' fins. Ya scallywag! T' lugs were spaced off t' body tubes to allow for t' uneven diameters betwixt them and I used a rod t' align them while they were epoxied in place. When t' rocket is final assembled a launch rod will be used again for alignment.
Painting:
T' rocket is now ready for paint. It was painted in sections very similar t' t' 1/100 Centuri version. This method involves less maskin' and easier handlin' o' t' parts. Begad! Even though there are only two colors, black and white, t' various roll patterns and separation lines require careful maskin' and prep that a fully assembled model would make much more difficult. Arrr! Ya scallywag! T' paint I used was Krylon. Avast, me proud beauty! It is a good all purpose enamel that goes on well and dries quickly. Ahoy! It also has t' advantage of flowin' t' colors back together betwixt coats because o' t' solvents used. (this can help if you get sags or minor runs)
I primed t' main body tube and t' core tube/fin unit. Arrr! Blimey! This helped show any defects or areas that needed more sandin' or filling. T' fuel tubes were painted directly (since they were already white in color and I did nay feel the need t' prime them), four black and four white. Arrr! Blimey! Avast! Blimey! T' capsule was painted glossy white separately as well as t' LES tower and t' LEM shroud adapter. Begad! Blimey! I then painted t' main body tube and core tube/fin unit glossy white. I let these dry for a day then masked and painted those areas glossy black. Arrr! Blimey! It is important to note that on t' corrugated areas t' get a good seal betwixt t' tape and the previous painted surface. This is t' prevent t' new color from bleeding under t' tape. It is also important t' let t' color coat dry for a few hours before removin' t' tape t' prevent liftin' or tearin' of the new coat. Avast, me proud beauty! Blimey! Ya scallywag! Blimey!
T' actual service module was a polished aluminum in color. It almost looked like chrome. Ahoy! There are no real accurate chrome type paints. I could have used chrome self-adhesive monokote trim sheet. Blimey! Aye aye! However, I did nay have any and cleanin' and use easily scratch t' chrome in general. Well, blow me down! I did cover t' service module section with aluminum colored monokote. Aye aye! This was then detailed with various pieces o' white trim monokote t' simulate panels and radiators found on the actual vehicle. Begad!
Recovery:
Recovery for t' Saturn 1b will be very similar t' t' 1/100 scale version. Aye aye! Avast! It will come down in two pieces with t' separation line bein' at t' base o' t' LEM shroud t' second stage body tube interface. Ahoy! Well, blow me down! T' LEM/SM/CM/LES stack will come down in a nearly horizontal position via a single 36 parachute by use o' a bridle fashioned from R/C aircraft control cable. Avast, me proud beauty! This bridle attaches t' an eyebolt at t' base o' t' LEM stack and t' an eyebolt screwed into a blind nut at the base o' t' service module. This eyebolt on t' service module is removable for static display.
T' main body will come down via dual 36 parachute recovery. Arrr! Blimey! For the main body section I wanted t' have it descend as close t' vertical as possible to reduce stress on t' fins at landing. This necessitates that t' shock cord mount be as close t' t' centerline o' t' rocket as possible. Aye aye! Blimey! There are two eyebolts on either side o' t' core tube in t' parachute compartment. Begad! Blimey! Blimey! A bridle slin' made o' 3/32 A/C cable connected with quick links connects t' an apex point a few inches above t' center o' t' core tube. Arrr! Avast, me proud beauty! Blimey! This is where the shock cord will attach and then continue t' t' parachutes.
This rocket is nay usin' any sort o' altimeter based ejection system. Arrr! Blimey! The flight profile I intend will allow for a motor based ejection system. Well, blow me down! Blimey! Begad! Blimey! It might be possible t' make provisions for one but I have nay gone t' t' trouble to investigate t' feasibility.
Final Assembly:
After t' various components are painted t' rocket is ready for final assembly. Aye aye! Ya scallywag! T' first stage fuel tubes slip into their respective positions and are lightly glued in place with super tacky glue.
Next comes t' main body tube t' core tube join. T' main body tube will slip over t' eight fuel tubes and trap them into place. Begad! Blimey! I put epoxy on the lower centerin' rin' o' t' main body tube and slipped it into position. Avast! Blimey! I used 30-minute epoxy so it would give me time t' position everythin' for line up. Here is where I used me ¼ launch rod again t' assure correct line up o' t' two assemblies. Blimey! Blimey! Ya scallywag! Blimey! Once t' main body tube was lined up I epoxied the upper centerin' rin' t' t' core tube. Aye aye! Blimey! I then set these completed assembly aside t' dry. Begad! Blimey! Avast, me proud beauty! Blimey!
I next attached t' command module t' t' LEM/SM stack. This be a friction fit only. Avast, me proud beauty! Begad! This will allow me t' add any nose weight t' achieve proper CG/CP relationship later. T' LES tower is attached t' t' command module. Begad! This is a friction fit as well so I can take t' tower off later for repairs if need be. T' fit is very tight though so I am nay worried about it comin' off in flight.
Finishing/Detailing:
After all t' epoxy has dried it is time t' add
the miscellaneous details. Begad! Ya scallywag! Usin' me 1/100 Saturn 1b for reference I attached
all t' ullage motors and conduits usin' super tacky glue t' their correct
positions. Begad! I attached t' four vernier motors t' t' service module as well. Ahoy! I
fabricated t' four antenna boards from sheet styrene and painted them white
with silver antennas. Begad! These were attached at t' four locations on t' first
stage.
A company in Texas called Model Graphics
provided t' decals for this model. Well, blow me down! Avast! They make custom vinyl self adhesive
decals. Avast! Ahoy! I have used them before for custom work on me R/C airplanes. Avast, me proud beauty! They do
outstandin' work. I sent them a .tif file o' t' decal set from Estes
1/70 kit and they were able t' scale them t' fit me 1/50 version. I highly
recommend them. Arrr! Aye aye! It may be a bit pricey but it is definitely worth it. Begad! Begad! Each set
they furnish comes with complete instructions on how t' apply their product. Begad! I
also ordered a set o' decals from Tango Papa custom decals. Avast, me hearties, me proud beauty! From these decal
sheets I used t' United States words and flags on t' CM and SM
plus t' various smaller target markings. Avast, me proud beauty! Aye aye! Tom Prestia, me bucko, t' owner, me bucko, has certain
Estes decal sets available and will upscale them for an additional charge.
These however, me bucko, me bucko, are water slide decals. Arrr! So you will have t' contend with
silverin' or clear edges if you dont clearcoat.
Motor Mount and Stability:
I tried t' model this rocket for CP usin' Winroc software. T' only drawback was that t' Barrowman equations for determinin' CP do nay support an eight fin configuration. I used six fins and added 10% t' t' fin dimensions t' allow for this. Well, ya bilge rat, blow me down! Blimey! I also compared t' balance point o' t' Estes 1/100 kit t' this upsized version and it is very close. Begad! Blimey! T' calculated CP is 31.45 inches from t' tip of the command module cone. Well, blow me down! Blimey! Avast! Blimey! I also believe that with eight fins t' CP would move further aft. My actual CG is well forward o' t' calculated CP (27 from the tip o' t' CM) so I am confidant that this will be a stable flyer without addition o' nose weight.
Since t' core tube is a 54mm diameter tube I used a LOC 54/38mm adapter. Avast, me proud beauty! Blimey! Blimey! Blimey! I assembled t' adapted per t' LOC instructions and epoxied it in place in the core tube. I used an AeroPac 38mm motor retainer. Avast, me proud beauty! Blimey! These things are t' slickest set up goin' for me money. Avast! Blimey! They are quick, neat and look so darn good. Avast! Blimey! Ahoy! Blimey!
Final Thoughts:
T' all up weight for this rocket is 3 lbs. 12
oz. Which is nay very heavy considerin' what has gone into it. There were
no real problems encountered while buildin' this bird. Blimey! Begad! I was able t' make
everythin' with relative ease usin' common materials. I flew t' rocket at our
clubs December 12th launch. Preppin' went uneventful. Arrr! I did nay brin' my
dual 36 chutes for t' main section so I used a single 54
chute. Ya scallywag! Everythin' packed nicely into t' recovery section with enough
room. Avast! T' motor be readied and loaded. Arrr! T' weather that day was perfect. Blimey! No
wind and clear skies. Begad! I got a far pad since this would be a maiden flight. Arrr! I
had t' photographers ready. And I prayed. Begad! T' motor lit right away and the
Saturn left t' pad very majestically (and stable). Then it happened. Ya scallywag! At about
300 feet t' ejection charge fired prematurely. Begad! Avast! T' rocket was still under
boost from t' H123. Ahoy! T' LEM/SM/CM stack separated and went off t' t' side.
Its recovery chute deployed perfectly. Ahoy! However, me bucko, t' main section was
another story. Well, blow me down! Avast! T' air load ripped t' chute away and actually broke t' main
bridle. T' main section continued up for a little way, ya bilge rat, arced over then headed
straight down for t' ground ready t' take a perfect core sample. Any doubts of
stability were allayed. Ya scallywag! T' main section headed straight in, shiver me timbers, struck t' ground
dead on and then bounced back into t' air about ten feet, me hearties, flipped end over end
twice and landed sideways on t' ground. Arrr! There be a hushed silence from the
crowd. My only thoughts were Oh well, time t' build another. All
that remained be t' 54 chute floatin' gently down. I headed out
to pick up t' pieces. Aye aye! Well, blow me down! When I got t' t' main body I was very surprised. The
damage was very minor. Aye aye! I expected t' whole forward section t' be crumpled but
it was not. Aye aye! Ahoy! There was no damage t' t' upper section, which recovered via the
parachute and thar was no damage t' t' fins either (this be always a concern
of mine on this model). Begad! All in all I be very, shiver me timbers, very lucky that day. Begad! T' damage
has since been repaired and I awaitin' t' final coat o' paint. Ahoy! All I did was
remove t' corrugated wrap from t' damaged portion, straighten t' tube and
reinforce with CA then cut some new wrap and glue it on, paint and finished. Begad!
T' model will fly again. Begad! Ahoy! Post mortem indicated from all witnesses that the ejection charge went off too soon. Blimey! As t' why this happened I am clueless. Begad! Well, blow me down! There may have been a void in t' delay element. Since t' motor be still under boost while this occurred it seems t' most logical assumption. Ya scallywag! Well, blow me down! Never t' less the Saturn will fly again. Well, blow me down! Begad! I have been told that me models are all too pretty to fly and that I must have nerves o' steel t' do this. Avast, me proud beauty! Aye aye! But me thinkin' is I build them t' fly, arrr, and if you fly em theyre gonna break. You can always build another. If you are interested in lookin' at any o' me other scale models then you can visit me web page at: http://www.geocities.com/CapeCanaveral/Hall/4501/index.html
This be t' only damage suffered on t' model from its death dive. Aye aye! I was amazed t' say t' least. Begad! Well, blow me down! Fortunately we were flyin' in a recently tilled bean field and t' ground was fairly soft. Even so an impact t' t' ground at over a hundred-mph is nothin' t' sneeze at. Aye aye!
List o' Materials & Sources:
(1) 5.68 LOC payload tube Magnum
(1) 5.68 LOC tube coupler Magnum
(1) 54mm motor tube Magnum
(1) 3 LOC body tube Magnum
(1) LOC 54/38mm motor adapter Magnum
(1) 3 LOC tube coupler Magnum
(1) 5.68/3.00 LOC centerin' ring Magnum
(4) 5.68/54mm LOC centerin' ring Magnum
(3) ¼ x 20 x 1.5 eyebolts hardware store
(1) 10-32 blind nut hardware store
(1) 10-32 x 1 eyebolt hardware store
(1) 3 length 1/16 A/C cable hardware store
(5) quick links hardware store
(3) pk scribed sheet styrene Evergreen
(2) pk .040 sheet styrene Evergreen
(4) .185 I.D. Aye aye! x 12 brass tube K&S
(4) .062 dia x 12 brass rod K&S
(1) BNC-5S nose cone BMS or Estes Designer Special
(1) BT-5 body tube (Estes) Magnum
(1) .190 x 12 wood dowel hardware store/hobby shop
(1) 1/32 x 12 x 24 veneer ply hobby shop
(1) ¼ x ½ x 12 balsa stick hobby
shop
(1) ¼ x 3/8 x 36 balsa stick hobby shop
(1) 1/8 x 6 x 12 A/C ply hobby shop
(1) 38mm motor retainer assy Aeropac International
Sources:
AeroPac International
Magnum Hobbies and More
Model Graphics
Tango Papa Decals
Evergreen
K&S Tubing
LOC Precision
Balsa Machinin' Service
Sponsored Ads
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