KosRox Apollo Pad Abort Test Capsule

KosRox - Apollo Pad Abort Test Capsule {Plan}

Contributed by David Fergus

Manufacturer: KosRox
Rating
(Contributed - by Dave Fergus)

Rocket PicBrief:
This model rocket is a 1/26.5 scale rocket o' t' Apollo pad-abort test rocket. It was used t' test t' Launch Escape System(LES). Ya scallywag! Aye aye! T' LES consisted o' a four- nozzle rocket motor set atop a supportin' tower with a dummy Apollo capsule. Avast, me hearties, me proud beauty! It was designed t' lift t' capsule away from an explodin' Saturn 5 booster. Ahoy! The kit model has a 5.8" base diameter, is 18" tall, has an 18mm motor tube, and uses streamer recovery. Begad! Aye aye! It weighs 2.8oz. Avast, me proud beauty! Well, blow me down! without an engine, me hearties, and 3.4oz with a B4-2. Blimey! It is available for $15 plus shippin' from KosRox.

Construction:
T' quality o' this kit is outstanding! All parts were o' high quality, precision cut, ya bilge rat, and easily identified from t' parts list and pictures. The packagin' was a heavy plastic bag. Begad! All parts were present and none were broken. There were nine paper shrouds precision cut t' t' correct inner and outer diameter, me bucko, with markings as appropriate. Blimey! Arrr! T' nozzle shrouds even had t' correct curves for installin' at t' correct angle after curlin' and gluing. Begad! Blimey! T' tower kit came in a separate little plastic bag that included all o' t' laser cut struts. Ahoy! Begad! T' nose cones are balsa, ya bilge rat, matey, and t' bulkheads are cardboard. Arrr! T' launch lug is heavy duty, which is necessary due t' t' kit design.

Note from KosRox: KosRox does nay supply decals. Arrr! Tago Papa or Jimz are better sources.

T' instructions are on 11 sheets with a picture accompanyin' all 39 assembly steps. Well, blow me down! T' instructions were logical, well written, and included good tips for easier construction, matey, such as clampin' shroud seams with spare balsa strips and clothespins while t' glue sets. Arrr! T' pictures that accompanied every step were clear, shiver me timbers, and were very helpful in clarifyin' t' written guidance. Aye aye! The kit maker included "heads-up" where he anticipated possible errors by the modeler.

I puzzled over t' instruction t' spray mat sealer on t' inside o' the printed capsule shroud. Begad! I did nay know what t' use, shiver me timbers, and finally guessed on Krylon clear sealer (my decal sealer o' choice). A caution here would be t' not touch t' shroud while it is drying, which I did and smudged t' black printing on t' capsule. Begad! Ya scallywag! T' pattern is printed on an ink-jet printer and easily smudges. Begad! Step 21 has t' " V" struts glued with a 1/4" inset. Shade this t' t' high side, shiver me timbers, or t' circular structure rin' will nay meet tips of t' "V"'s.

Rocket PicStep 33 on t' shockcord attachment is confusin' and needs better instruction. Well, shiver me timbers, blow me down! Blimey! T' intent o' puttin' a loop in the Keelhaul®©™® shock cord is t' use t' motor tube as t' anchor t' shock cord pulls against. Only after t' motor tube is inserted through t' top bulkhead, the loop in t' shockcord, and then t' bottom bulkhead; should t' shockcord be pulled taut through t' small hole in t' bulkhead, and glued. Begad! Because I did this out o' order, arrr, shiver me timbers, me shockcord loops around t' motor tube, shiver me timbers, but has useless slack inside t' bulkhead. Begad! Arrr! All o' t' shockcord strain is felt by t' upper bulkhead on me model.

Finishing:
For finishing, me hearties, Elmer's F&F filled in t' grooves on t' BT-50 tower tube, smoothed t' capsule and tower nose cones, shiver me timbers, and t' shroud folds. Well, blow me down! T' roll pattern was done by usin' black electrician's tape. It makes a lot straighter lines than tryin' t' mask and paint. Blimey! I rate this a 4.5 for construction due to the few minor nits mentioned above.

Construction Rating: 4 out o' 5

Flight/Recovery:
Care must be taken when packin' t' crepe streamer so that it will deploy upon ejection. Begad! When asked about prototypin' t' recovery system t' include 3 tiny chutes, t' kit designer leaned against it. Well, blow me down! He had tried a chute and they did not deploy consistently due t' inward slope o' t' body cavity. Ahoy! Avast, me proud beauty! On one o' his early designs with only one shroud instead o' two, me bucko, t' model be light enough for tumble recovery, me bucko, but durability demanded double shrouds which leads to streamer or chute for t' added weight. Aye aye!

Because o' t' large 'cone' area o' this rocket, it does nay build up a very large velocity. Begad! Arrr! At motor burnout, ya bilge rat, it decelerates very rapidly. T' kit recommends a B6-4 for first flight, but I would use a B4-2, especially if you use several coats o' white paint on t' tower assembly. Aye aye!

Rocket PicRocket Pic

Another big caution is t' make sure t' launch rod is clean as a whistle, and maybe even lubricated with baby powder. Well, blow me down! Blimey! This rocket could stick on t' rod due t' t' large moment arm betwixt t' motor and t' top tip o' t' launch lug. Well, blow me down! T' launch lug needs t' be long t' go through t' whole body o' the capsule, shiver me timbers, but also has t' be offset from t' motor tube t' clear t' tower assembly. Ahoy! Begad! Blimey!

T' motor is retained by tape friction rather than a hook, ya bilge rat, arrr, which would detract from t' appearance. I rate this a 4.0 due t' t' inherent design difficulties o' launch and recovery. Begad! Arrr!

Flight Rating: 4 out o' 5

Summary:
Overall: I rate this kit a 4.5 due t' t' uniqueness o' t' prototype, me hearties, care in the design and appearance, me bucko, value for t' $15 price, durability, me bucko, shiver me timbers, and t' new skills it taught me. Avast!

Overall Rating: 4 out o' 5

Q&A with Damian Kostron o' KosRox:

1. How did you paint t' roll pattern on t' upper body tube?
T' roll pattern on me model ended up bein' black electrical tape. Blimey! I painted the jet rocket and applied a couple strips o' black tape. Well, blow me down! Blimey! Yeah, ya bilge rat, that is cheating, me hearties, but it works. Begad!

2. I really puzzled over what you meant by mat sealer. I ended up usin' some Krylon clear (the same thin' I use t' seal and cover decals), and it worked for it's intended purpose t' keep t' epoxy from leachin' through t' mar t' finish o' t' printed shroud; and except for touchin' it while wet, would have been perfect.
'mat sealer' - any clear spray paint type o' product that will provide protection from moisture.

3. I was intrigued by your photos o' some sort of glue applicator out o' me experience. Blimey! Ahoy! Blimey! I used Elmers Carpenters Wood Glue for external use, unless you specifically called out for CA or epoxy. Blimey! Blimey! It has the property o' nay runnin' and a small amount holds parts together while you orient them, me hearties, matey, shiver me timbers, and is sandable. Blimey! T' downside is that it shrinks. I used it to anchor t' wood dowels t' t' strut parts, and then backed it up with CA.
T' applicator is a nifty oilin' bottle originally used for applyin' small amounts o' oil in tight areas. T' 'needle' o' t' bottle is very large (in comparison t' a hypodermic needle) and allows me t' use Elmers wood glue (construction glue) in it. Begad! Blimey! Although, me hearties, frequent cleanings are necessary.

4. Avast, me proud beauty! I messed up and touched t' large shroud while it was still damp from t' sealer that I sprayed on t' inside. Ya scallywag! I have a few smudges o' t' black print into t' white areas. Any suggestions as t' how to touch up?
Smudges...bummer. Blimey! I used an Ink-Jet printer for t' printed shrouds. Well, blow me down! T' ink is water soluble (I expect that thar are a few other things that will dissolve the ink as well). Blimey! Well, me bucko, blow me down! A clear over coat (like t' 'mat sealer' or your Krylon clear coat) is t' protect t' shroud from smudging. Begad! T' only thin' I could think of to fix yours it t' use a little white touch up paint on t' smudge itself.

5. Avast, me proud beauty! Ya scallywag! One other item o' feedback be t' shock cord attachment t' t' main capsule. Begad! Ahoy! I did nay do it quite right, upon reflection, in that after t' engine tube was affixed would have been t' time t' pull the cord and loop tight and then glue where it goes through t' bulkhead hole. I am afraid that me loop is still loose and t' anchor be t' bulkhead itself. Begad! Well, blow me down! Your description o' how t' do this be a little bit o' a puzzle. Begad! Should I reinforce the bulkhead somehow with cross bracing?
T' shock cord is supposed t' loop around t' main engine tube. It will be impossible t' do this, matey, me bucko, once this tube is glued in place. Well, blow me down! Avast, shiver me timbers, me proud beauty! Yes, shiver me timbers, shiver me timbers, it does provide for an interestin' puzzle durin' construction (and a little dexterity). Ya scallywag! This 'loop around t' engine tube' is t' provide strength t' t' shock cord. If your shock cord has a knot that does nay allow it t' pull through t' upper bulk-head (but does nay loop around t' engine tube). Aye aye! Well, blow me down! I would suggest a reinforcement consistin' o' a penny sized piece o' card stock with a small hole in it's center (just big enough for t' shock cord). Then epoxyed into place (effectively reinforcin' t' main bulk-head, keepin' your knot from pulling through). Avast! Begad!

6. Avast, me proud beauty! I am nervous about t' strength o' t' upper shroud. Ya scallywag! Have you had shock cord damage o' that shroud? Is thar a way to reinforce t' inside o' that shroud? Any other hints on avoidin' damage during recovery other than lubricatin' t' launch rod? I am nervous about the shockcord/streamer arrangement. Begad! T' upper portion seems awfully close t' the main capsule... Avast! I am inclined t' brin' them down in two pieces with two small chutes. A chute on t' main capsule would be closer t' t' prototype, wouldn't it?
This is a complicated series o' question(s), with many possible answers. Begad! Let me start by tellin' you about me 'boiler plate' models. Avast, me proud beauty! I built three o' them. Well, blow me down! One was built with single layer shrouds (both on t' nose section and t' main capsule) with parachute recovery. Arrr! Avast, me proud beauty! T' second one was built with double layer shrouds (both top and bottom) and streamer recovery. T' third was double layer bottom and single layer top with tumble recovery (no parachute or streamer) and no shock cord attachin' t' pieces together. Begad! I built these models in stages based on t' outcome o' t' previous model (I intended on flyin' them until they broke). Begad! On t' first model several things happened that caused a redesign of t' rocket. Avast! T' single layer main capsule was always gettin' very damaged (the single layer card stock just wasn't strong enough). Aye aye! Also, me hearties, shiver me timbers, I could nay keep the parachute from becomin' 'char-broiled' (I think this has somethin' t' do with t' inside shape o' t' parachute/streamer packin' area). Arrr! T' second model fared a lot better with very little damage t' t' main capsule. Ahoy! However, me hearties, me hearties, I found that t' rocket tended t' be a bit on t' heavy side. Ahoy! T' third model is the one I continue t' fly today. It is tumble recovery and sustains very little damage on recovery (if I fly it on a nice grassy field). Blimey! I elected t' provide (in t' kit) a way o' makin' t' second model, as it be much more durable. However, this is where a streamer becomes necessary as t' model is heavier (somethin' be needed t' slow t' decent rate). Begad! If you are inclined t' fly it 'prototypically', me bucko, me hearties, me hearties, then you should have three parachutes on t' main capsule (and provide whatever protective recovery means you want t' t' tower). Although, matey, me bucko, ya bilge rat, I think you will find it very difficult (maybe impossible) t' pack three parachutes into t' rocket and t' get them t' reliably deploy. Begad! Recovering the capsule and tower separately would eliminate t' chance o' damage (due to parts 'snapping' back at each other). Avast, me proud beauty! Well, matey, blow me down! However, ya bilge rat, when you pack t' recovery devices (parachutes/streamers/what ever you use), make sure t' upper device is packed underneath t' lower. This will help insure that t' lower device is 'pulled' out. Well, blow me down! (I have had cases where t' lower parachute would nay come out of the tight packin' area o' t' main capsule). T' reinforce t' upper shock cord mount, just make sure thar be ample glue saturatin' t' cord and that it has at least 1 inch or more o' t' cord imbedded in t' glue. Avast! Make sure t' glue doesn't interfere with t' balsa nose cone and it's fit t' t' main engine tube. Ahoy! Arrr! If you fly it in two separate pieces, thar will be very little stress on the upper shock cord mount. Arrr! Because o' t' large 'cone' area o' this rocket, ya bilge rat, me hearties, it does nay build up a very large velocity. Avast! Avast! At motor burnout, it decelerates very rapidly and will be travelin' very slow at ejection (always use a short motor delay because o' this). T' double layer o' shroud cardstock was me way of reinforcin' t' shrouds. T' upper shroud is unique in that it be t' support for t' tower. Avast, me proud beauty! With t' single layer upper shroud, me hearties, I would see damage if I tried streamer or parachute recovery (both pieces together). Well, blow me down! But, me bucko, it would only sustain minor scuffs if recovered as separate units. Blimey! Regardless o' what recovery method is used, try t' have t' tower section fall horizontally (I know, it is difficult t' determine this with out first flyin' it, and then it may be too late). Arrr! Begad! I have found that if t' upper and lower pieces are recovered separately usin' streamer recovery, and that if t' tower is too nose heavy, that t' tower will fall nose first and will actually accelerate towards the ground. Ya scallywag! Avast!

comment Post a Comment