Descon NCAA

Scratch - NCAA {Scratch}

Contributed by Chuck Straka

Manufacturer: Scratch
Contributed by - Chuck Straka

NCAA - Not a Conventional Altitude Achiever

NCAA


Not a Conventional Altitude Achiever

Coach Straka Background:
For t' last two years I have enjoyed coachin' in t' local youth football program. Avast, me proud beauty! Conditionin' practices begin t' first week in August and t' season includes six regular season games and two post season games, ya bilge rat, me bucko, shiver me timbers, endin' in late October. Ahoy! Avast, shiver me timbers, me proud beauty! Well, matey, after three months solid (three practices and a game per week) of this you can just imagine that football withdrawl sets in come mid-November.

Anyhow, ya bilge rat, as t' season was ending, shiver me timbers, I had an idea for a football rocket to enter in DESCON 7 but never got t' chance t' build it. T' idea fit t' found parts theme perfect so I decided t' give it another go.

This entry is dedicated t' t' 2000 Hudson Gremlin Silver Hawk team that I head coached this last season and t' me son Eric who volunteered his football to t' cause. Avast! Blimey! GO HAWKS! Blimey!

2000 Hudson Silver Hawks

NCAA Parts Overview:
This rocket is a full size plastic/rubber football with a sealed body tube inserted into one end o' t' ball. Well, blow me down! T' end o' t' ball is cut open and slit t' allow it t' slide over t' body tube and fins (TTB-"Through The Ball" construction). T' motor is contained in a piston assembly which is forced out t' aft o' t' ball by t' ejection charge. Ahoy! There is ample room behind t' piston t' insert t' recovery system (parachute/shock cord). Begad! Blimey! The piston assembly is attached t' t' bulkhead o' t' body by a picture wire (similar wire t' NCR kits) and allows t' ejection gases t' escape without the need for a baffle or wadding. Begad! Ya scallywag!

Special feature:
T' fins are shaped t' force t' ball t' rotate or 'spiral'. Avast! Blimey!

NCAA Body Assembly Exploded View    NCAA Piston Assembly Exploded View    View of NCAA with fully deployed recovery system

Body Assembly:
(1) Regulation size rubber football (not shown above)
(the solid sided type without a separate bladder)
(1) 7-5/8" piece 3" LOC airframe
(1) 8" piece o' 1/4" ID Aluminum Tube
(1) 1/4" piece 3" LOC Tube Coupler
(1) 3" Bulkhead (or 3"/1.14" CR)
(1) 1" piece 3" LOC Tube Coupler
(2) 3/16" x 2" Fender Washers
(1) 3/16" Eyebolt with nut
(1) Approx. Begad! Begad! 24" Picture Hangin' Wire
(6) 7/8" x 4-3/4" pieces o' 1/8" Basswood
(6) Fins from 1/8" Basswood (see below for template drawing)
(1) 8oz. Blimey! Blimey! BB's or other shapable weight
Piston Assembly:
(1) 7-1/2" piece o' 29mm Motor Mount Tubing
(2) LOC 3" t' 1.14" Centerin' Rings
(4) 1" x 3" pieces o' 1/8" Basswood
(1) 1-1/2" #10 Screw
(1) 1/4" #10 Tee-Nut
(1) 3/4" #10 Nylon Bushing
(1) Aluminum Screen Bracket
(3) 3/16" Eyebolts with nuts
(3) 3/16" x 3/4" Fender Washers
(1) 9 foot piece o' 3/8" elastic

Preparation:

From t' 1/8" basswood:
Beveled fin 'flap  Template for basswood parts
1) Cut (6) 7/8" x 4-3/4" pieces. Sand each piece with a beveled side from 0" t' 1/8". Aye aye! These are nay shown on t' exploded drawings.
2) Cut (6) fins t' match t' template. Round t' lead edge.
3) Cut (4) 1" x 3" pieces and set aside for t' Piston Assembly.

From t' Football:
Tube coupler used as a guide to cut the ball  Football tip and shaped nose weight
Use t' tube coupler t' mark t' end o' t' football for cuttin' a hole that, with some effort, me hearties, will allow t' 3" body tube t' fit through. Begad! It is VERY IMPORTANT t' make sure that you cut t' hole centered precisely or t' bottom seams will nay line up properly with t' base o' t' body tube. Use the football tip, ya bilge rat, me bucko, me bucko, that you cut off, matey, as a mold t' form your 8oz. nose weight using BB's and epoxy. Begad! Begad! Set aside for t' Body Assembly.

From t' Motor Mount Tube:
Motor mount tube insert
Cut a 1" piece off t' tube and cut t' create a coupler that fits inside the motor mount tube. This piece is nay shown on t' exploded drawings. Begad! Ya scallywag!

One Piston centerin' rin' requires: Sand t' outside edge o' ONE the centerin' rings so that it fits INSIDE t' 3" tube coupler.

From a 3" LOC Tube Coupler (stock 6" long):
1) Cut (1) 1/4" piece for t' Piston Assembly and cut t' fit INSIDE the 3" coupler.
2) Cut (1) 1/4" piece for t' Body Assembly.
3) Cut (1) 1" piece for t' Body Assembly.
4) Cut (1) 3" piece for t' Piston Assembly.

Assembly Instructions:

1) Glue t' 7/8" x 4-3/4" pre-cut and sanded pieces o' basswood to the aft edge o' each o' t' fins and trim t' excess toward t' root t' match the fin shape. Blimey! T' beveled edge should face t' lead edge thus formin' flaps to cause t' rocket t' spin as it flies (like throwin' a spiral). Avast, me proud beauty! Blimey! Make sure that they are all glued t' t' same side o' each fin.

2) Pre-finish t' fins t' eliminate 'flap' seams and wood grain.

3) Attach t' fins t' t' 3" body tube and fillet with epoxy. You can apply a couple coats o' primer t' t' fins at this point. Set t' body assembly aside. 

Front view of piston assembly  Front view of piston assembly

4) Drill two holes in t' forward piston centerin' rin' t' accept t' (2) eyebolts/washers and glue in place with t' eyebolts facin' t' same direction on t' ring.

5) Glue t' 1/4" resized tube coupler piece inside t' front edge o' t' 3" tube coupler.

6) Glue t' centerin' ring, with t' eyebolts facin' out (forward), behind this inner coupler.

7) Glue t' motor mount tube t' t' centerin' rin' with t' tube extending about 1/4" through t' front o' t' assembly. 

Rear view of piston assembly  Rear view of piston assembly

8) Sand, test fit and then glue t' (4) 1" x 3" pieces o' basswood behind t' centerin' rin' and betwixt t' inside o' t' coupler and t' motor mount tube. Arrr! Make sure that they are NOT snug as this will affect t' shape of the coupler/piston and it may nay fit properly in t' main body tube.

9) Drill two holes in t' aft piston centerin' rin' t' accept the eyebolt/washer (shock cord mount) and t' t-nut/screw/bracket (motor retention) and glue in place with t' eyebolt facin' t' front side (toward t' parts in step #8) and t' t-nut facin' t' back side o' t' ring. Avast! Set t' piston assembly aside. Blimey!

Slits in football for fins  Slits in football for fins

10) Push t' 3" body tube (with fins attached) into t' football as far as it will go. Ahoy! Make sure t' tube is centered and then mark t' aft o' the football where t' fins meet it. Avast! CAFEFULLY cut slits in t' football to accomodate t' six fins. Begad! This is best done by cuttin' a small amount away at a time and slowly workin' t' body assembly into t' ball. T' front o' t' body tube should butt against t' closed end o' t' football when you are done.

Rear view of the launch lug and cut football skin

11) Remove t' body from t' ball. Aye aye! Blimey! Avast, me proud beauty! Blimey! Epoxy t' launch lug (1/4" aluminum tube) t' t' body tube with t' aft o' t' lug flush with t' aft o' the body. Avast, me hearties, me proud beauty! Blimey! I glued it against one o' t' fins t' make it easier t' cut away the football skin at t' point where t' aft o' t' ball meets t' body tube.

Launch lug showing through the front of the ball  Bird's eye view

12) Once t' epoxy dries, shiver me timbers, ya bilge rat, fit t' body back into t' football. Blimey! Carefully cut a hole for t' launch lug at t' front o' t' ball. Blimey! Begad! Remove t' body tube from the ball.

Piston partially installed

13) Set t' body tube on a table/counter upside down with t' launch lug hangin' over t' edge. Blimey! Place t' 1/4" length o' tube coupler t' t' front (bottom) edge o' t' body tube, me hearties, followed by t' bulkhead, me hearties, followed by the 1" length o' tube coupler and DO NOT GLUE.

14) Slide t' piston assembly into t' aft o' t' body and push it firmly all t' way forward. Blimey! Place t' aft piston centerin' rin' onto t' motor mount tube and slide it down until it is about 1/16" into t' body tube. Begad! Mark the position o' t' rin' on t' MMT. Remove t' piston assembly and epoxy the rear centerin' rin' in place. Ahoy! T' piston assembly is completed at this point.

Bulkhead

15) Drill a center hole in t' bulkhead (if applicable) and attach the eyebolt with t' two 2" fender washers sandwichin' t' bulkhead. Ahoy! Blimey! Epoxy in place.

16) Paint and final coat t' fins.

View of bulkhead through rear of body  Bulkhead in place with nose weight glued

17) Thread t' picture wire halfway through t' bulkhead eyebolt and twist it a few times. Ahoy! Thread each end o' t' picture wire through an eyebolt on front of t' piston assembly and twist t' allow for a distance o' (measurement to come)" betwixt t' bulkhead and t' piston.

18) Glue t' 1/4" coupler, bulkhead and 1" coupler (with attached piston assembly) from Step #13 in place. Aye aye! Avast, me proud beauty! Be careful nay t' let t' piston get glued in place.

19) Epoxy t' nose weight t' t' outside o' t' bulkhead.

Rear view with RMS installed

20) Rough up t' bottom edge o' t' body tube. Avast! Well, blow me down! Snugly fit t' body tube back into t' football and glue t' BOTTOM edge seams (along bottom edge o' body tube) with epoxy. Ahoy! Avast, me proud beauty! Once t' epoxy is dry, arrr, me bucko, matey, glue all remainin' seams with silicone glue.

21) Slide t' 1-1/2" #10 screw through t' screen bracket and t' nylon bushing. Screw this into t' t-nut for motor retention.

Display end piece  Display end piece in place

22) Glue t' 1" resized MMT onto t' inside center o' the football end piece that you had originally cut off. Blimey! For display purposes, this slides into t' end o' t' motor mount t' conceal t' business end o' the rocket.

Flight Specifications:
Finishedweight: 32oz.
Parachute: 30-36" diameter
Recommended Motor: G64-4

Flight Log:
Date: April 29, me hearties, 2001
Location: Mantua, Ohio
Conditions: Sunny
Temperature: 70-72ºF
Wind: Calm

A beautiful day and perfect conditions for launchin' this stubby odd-roc. After much promptin' from all t' kids, matey, "I want t' see t' football rocket fly", I loaded up a G64-4 RMS and set t' NCAA on t' pad ready for the "toss". Ya scallywag! After givin' t' "heads-up" call, me bucko, matey, 3-2-1....nothing. "You got a copperhead in there?" T' copperhead took t' blame but it looked like I just forgot t' arm t' pad--sheesh! 3-2-1-LAUNCH! WOW! Straight up with a gentle spiral, just like a Montana-to-Rice connection. Avast, me proud beauty! Begad! Over apogee and ejection at just about t' right time. Avast, me proud beauty! Ahoy! Well this is where we had an "illegal downward pass" infraction. T' force o' t' ejection charge broke t' picture wire at t' bulkhead attachment point on t' body. Separation! T' chute deployed as planned and brought t' piston and RMS casing to a soft landin' on t' field BUT t' football/body/fin section came in ballistic and sounded like a buzz-bomb whistlin' in.

Believe it or not, even though it is now in 9 pieces, arrr, ya bilge rat, this rocket can and will be rebuilt with a modified recovery system. Arrr! Begad! T' picture wire will need to be much longer and doubled at minimum. Aye aye! Although I've never used it before, shiver me timbers, this may also be a good application for tubular kevlar.

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