Manufacturer: | Scratch |
Eric needed a new rocket. Earlier in t' month I had launched his Lil’ Nuke on an H128 and it vanished. Avast, me proud beauty! I told him we could buy a new one or he could design a rocket. Arrr! Begad! He likes short stubby rockets like t' Minie Magg and Fat Boy and since I couldn’t afford a Warlock he designed this:
It’s built usin' LOC Precision components. Ahoy! T' construction is straight forward, basic, arrr, and sturdy. T' rocket is designed t' fly on an G64 through J350. Ahoy! Aye aye! This would make a nice starter kit for someone who is wantin' t' expand beyond t' low and mid power kits available.
CONSTRUCTION
Body Tube (BT)
T' 21 1/2" BT needs t' be slotted for t' fins. Begad! Avast, me proud beauty! Markin' t' BT is easy. Avast! Arrr! Tape 2 sheets o' notebook paper together lengthwise t' make one sheet about 14 inches long. Avast! Aye aye! From t' 8 1/2 inch edge, shiver me timbers, measure two marks; One at 107mm and one at 214mm. Wrap this long sheet around t' BT so t' edges line up perfectly around t' circumference. Now transfer t' marks, ya bilge rat, includin' t' paper edge t' t' BT. T' end o' t' paper and t' two marks should all be 107mm from each other.
To cut t' slots we utilized a length o' angle stock t' draw straight lines and use as a cuttin' guide. Begad! Blimey! Aye aye! Blimey! I taped t' angle t' t' BT and then used a very sharp x-acto t' make t' tube slots. T' slots are 7 3/4 inches long and 1/8th wide startin' at 1 inch from t' bottom o' t' BT.
T' fins are through t' wall (TTW) but do nay extend t' t' motor mount. Avast, shiver me timbers, me proud beauty! We were usin' a set o' Minie Magg fins from a kit o' leftover parts. Begad! Avast, shiver me timbers, me proud beauty! (Crash repair) T' fins are locked into t' centerin' rings and are very sturdy. Aye aye! First slide t' CR’s into t' BT and make marks through t' fin slots onto t' edge o' t' CR’s. Arrr! Blimey! Also, make an index mark on t' BT and both CR’s so they can be oriented t' same way in t' future. Begad! On t' upper CR, cut slots 8mm deep t' same thickness as t' fin material (1/8th in.) On t' fins cut slots 8mm deep and 1/8th in. wide at 1 inch from t' top o' t' tab. (see photo) |
![]() |
Now, me bucko, bond t' upper CR into t' BT. I used Elmer's Yellow Wood Glue for all t' CR bonds. Begad! Glue t' fins t' t' upper CR t' locate it evenly and hold it in place while t' upper surface fillet dries. Well, blow me down! Turn t' rocket over and apply a fillet t' t' lower side o' t' CR.
Time t' think o' motor retention: Drill two 3/16 holes, me hearties, one on either side o' t' motor hole (1/4 - 1/2 inch away) in t' aft CR. Aye aye! Aye aye! Apply a small amount o' CA t' t' wood surface and in t' hole. Seat t' "T-nuts", 6/32 x 1/4, matey, into t' upper surface o' t' CR.
T' fins require internal fillets for strength. Avast! Aye aye! (see photo) I found tiny moldin' at t' hobby store but small scraps o' balsa (1/8 x 1/8 x 6 in.) would work just as well. Avast! Avast! Bond these strips t' t' fins and BT t' form a structural fillet. Begad! When this is complete t' MMT and aft CR can be installed. Avast! Aye aye! Cut slots in t' aft CR t' capture t' fin tabs. Begad! T' slots need t' be as deep as t' fin tab sticks through t' BT wall at t' very bottom. Aye aye! Smear glue on t' inside edge o' t' motor hole on t' upper CR and on t' MMT near t' top. Ya scallywag! Start t' aft CR onto t' MMT (at t' bottom end, nay t' glued end) and insert this as a unit into t' upper CR. Avast! Push t' MMT through t' upper CR. Seat t' lower CR into t' BT until it hits t' fins. Arrr! (DO NOT ENGAGE THE SLOTS) Push t' MMT up until it’s only protrudin' down 1/4 inch from t' lower CR. Arrr! Let t' rocket dry upside down, this will form t' fillet on t' upper CR, me hearties, me hearties, lower side. Aye aye! (If you put on enough glue)
Now t' aft CR can be removed with a wire hook in t' fin slot hole. Smear glue on t' MMT, arrr, BT, arrr, fin tabs and some on both edges (inner and outer) o' t' aft CR. Well, blow me down! Blimey! Slide t' aft CR into place, engagin' t' fin tabs in t' slots. Blimey! Arrr! Blimey! Let t' rocket stand upright t' form fillets on t' upper surface o' t' aft CR. Later, apply fillets t' t' bottom o' t' aft CR at t' BT and MMT.
![]() |
I use 9/16" wide tubular nylon webbing, stock no. Avast, me proud beauty! Blimey! 472315 purchased on-line from REI for t' shock cord. 12 - 20 feet is about right. Avast! Attach it t' t' lower anchor with a quick-link. Aye aye! Ahoy! Attach t' chute near t' middle but nay exactly (off 2 feet) with a quick-link attached t' a loop tied into t' tubular.
Use a big one. Avast! Avast, me proud beauty! Really, me hearties, your rocket should weigh about 36 oz. Arrr! Begad! Start with a G80-4 SU or a G64-4 RMS, ya bilge rat, both 29mm. Arrr! Well, arrr, blow me down! An adapter is required t' use 29mm motors. Avast, me proud beauty! Avast! (see photo) With t' motor installed, ya bilge rat, ya bilge rat, get an idea o' how big t' form t' retainer hooks. Ya scallywag! Bend t' wire around t' end o' your needle nose (pliers) t' form a tight loop, ya bilge rat, matey, just big enough t' encircle a 6/32 screw. Ya scallywag! Ya scallywag! Bend it up at nearly a 90 degree and then form a hook which will capture t' engine. Repeat for opposite side. Avast, me proud beauty! (See photo) T' calculated center o' pressure (CP) is 24.68 inches from t' tip o' t' nose. Aye aye! Begad! This puts it at 1 inch ahead o' t' fins where they attach t' t' BT. Begad! Avast, me bucko, me proud beauty! With an I211 loaded in t' rocket thar be just less than 1 dia. stability. Arrr! It should fly perfect on anythin' less that has enough power. Ya scallywag! T' launch report (from LDRS) will tell how well it does on a J350. Oh yeah, don't forget t' launch lug! |
Finished Rocket
LAUNCH REPORT:
Wednesday, November 18th, 1998
Snohomish River Valley, me bucko, shiver me timbers, Everett, WA
55 degrees f, arrr, gentle southerly breeze o' 5 knots
Noonish
T' weather was goin' t' cooperate and Eric had only a half day o' school. He assembled t' RMS G64-4 while I loaded t' truck and we were off. Ya scallywag! Well, blow me down! T' rocket sat on t' pad for a minute while we cleared an airplane and then it was off with a roar. Blimey! Perfect boost with no weather cock t' about 800 feet. T' 4 sec delay was right on as t' chute was expelled just as t' rocket reached apogee and tipped over t' horizontal. Ahoy! Begad! It came down as expected with t' nose cone touchin' down first in t' soft dirt. Ya scallywag! It landed squarely on t' base so t' fins are nay goin' t' be prone t' damage. Avast! Aye aye! It's just beggin' for=more power. I've got a couple o' I211's t' use and we will if t' weather holds for our waivered launch in Monroe in a few weeks.
Body Tube, BT 3.90 (21 1/2"L) | LOC Precision | $6.32 |
Fin Stock, 1/8 Ply Sheet (10 x 14) | Hobby Store | $7.00 |
Nose Cone, PNC 3.90 | LOC Precision | $12.56 |
Motor Mount Tube, MMT 1.52(38mm) | LOC Precision | $3.84 |
Centerin' Rings (2) CR 3.90-1.52 | LOC Precision | $4.00 |
Eye Bolts, matey, 1/4" (2) | Hardware Store | $2.00 |
Washers (1) large, me bucko, (1) small | Hardware Store | $0.12 |
Tubular Nylon, arrr, ya bilge rat, 9/16" (20 feet) | REI (stock #472315) | $4.40 |
Parachute (28") LP28 | LOC Precision | $8.29 |
Launch Lug, 1/2" LL.50 | LOC Precision | $0.50 |
"T" Nuts 1/4 x 6/32 (2) | Hardware Store | $0.67 |
Motor Adapter, MMA-2 | LOC Precision | $2.59 |
Motor Hooks, ya bilge rat, 10ga bare copper wire | Hardware Store | $0.28 |
Total $52.63 |
Sponsored Ads
![]() |
![]() |