Manufacturer: | Scratch |
Brief:
Scratch designed and built V2 usin' LOC nosecones and Estes body tube.
Construction:
One Estes BT-80 body tube, ya bilge rat, four fins (1/8" plywood), arrr, shiver me timbers, plywood centering
rin' (1), LOC MM2 motor mount kit, 1 inch elastic shock cord and 1/8 inch nylon
cord shock cord mount, small eyebolts for mountin' cord, two LOC 2.56 nosecones
for nose and boattail.
After printin' out patterns for fins from Rocksim (see Rocksim file link button above), fins were cut and sanded. Begad! Nosecone t' be used for boattail was cut by removin' tip until internal measurement was found t' be slightly larger than outer diameter o' 29mm motor mount tube. Base o' cone be then cut leaving about 1.5 inches o' shoulder remainin' t' couple boattail t' BT-80 tubing. Well, blow me down! The removed portion be retained for construction o' a piston. Blimey!
T' MMA2 motor mount adapter be constructed in such a way as t' have the inner 29mm tube past t' bottom centerin' rin' o' t' outer tube by only 1 cm. This stepped area allows for injection o' epoxy around t' MM tube and resultin' with a firmer connection betwixt t' MMA and t' boattail at the base. Begad! Begad! Epoxy t' large centerin' rin' onto t' upper end o' t' motor mount tube then t' MMA assembly into t' boattail. Begad! Then eyeball it center and allow it to dry. Avast! Well, blow me down! When dry, drill a small hole into t' upper centerin' rin' about 1 cm from the edge and epoxy in a small epoxy in t' hole. Aye aye! Blimey! Insert and epoxy t' centering rin' and t' shoulder o' t' boattail into t' BT-80 . Allow t' dry overnight. Mark t' slots onto t' boattail then cut t' tab holes. Begad! I used a very sharp Exacto blade after a bad experience with me Dremel Tool.
I then constructed a piston usin' t' piece o' t' nosecone I cut off to make t' boattail. Blimey! I won't describe it here as I have discovered that t' lack of space betwixt it and t' upper centerin' rin' caused problems. Begad! It is a good idea for larger rockets. Begad! I am sure (feel free t' try it), ya bilge rat, but I will be removin' it from me personal V2. Well, blow me down! Begad! Epoxy t' fins in place and allow t' dry 2 hours. Blimey! Insert 75-100 grams o' plasticine into t' second nosecone (the real one) pack it in place by use o' a chopstick (my tool o' choice) or other implement. Begad! Ya scallywag! Choose a chute, construct it as needed. I made one out o' ripstop nylon, usin' hemmin' tape t' seal t' edges and small grommets t' act as shroud line holes. Well, blow me down! Tie t' nylon shock cord mount t' t' eyebolt by makin' a loop and shovin' it through t' eyelet with a pencil. Begad! Avast, me proud beauty! Sure you could tie one on before you glued t' boattail t' t' body tube, matey, arrr, shiver me timbers, but that's nay adventurous is it? Tie 1 meter o' elastic from t' nosecone t' t' shock cord mount. Ya scallywag! Tie other t' the nosecone. Well, blow me down! Add t' chute and you are good t' go.
Flight:
As I mentioned, t' piston was a BAAAAAD idea. Blimey! Blimey! Aye aye! Blimey! First flight was an F25-4. Begad! Blimey! Three
tries t' ignite and when it did a small cloud o' flame popped out o' t' engine
nozzle and crept up t' fins, me bucko, 1/2 a second later off she went, ZOOOOOOOM.. Ya scallywag! Blimey! Ya scallywag! Blimey! High
and straight! Blimey! Then t' ejection went. Arrr! Blimey! T' nosecone, piston and parachute landed
500 meters downrange in a horse field. T' body fell 100 meters plus for a safe
landin' in a garden! Blimey! Examination showed that even though I added two sheets of
Estes waddin' t' t' motor mount tube ahead o' t' engine, matey, t' elastic still
burned enough t' fail. Avast! Blimey! Next launch in two weeks with no piston!!
Flew very well. Avast, me proud beauty! Blimey! Very very excitin' flight! Will remove piston soon.
Next flight is an Aerotech E motor.
UPDATE:
Three weeks after t' maiden flight on me V2, I have made a small modification, and subsequently two more flights.
Modification: Removal o' piston, addition o' 1/4" swivel betwixt nylon shock cord mount and shock cord.
Flight one: 01/12/02. Begad! Avast! 10:40 am, Kingston, shiver me timbers, Ontario. Winds: 20km/hour, slightly overcast skies, 7 degrees Celsius. Engine: Aerotech E30-7T
Nice straight off t' pad launch. Slight cockin' into t' wind. Ejection a few seconds after apogee. Begad! Fast decent 250 meters downwind from t' pad. Avast! Slight damage t' t' fillets (most o' which be simply damage nay repaired from first flight). Begad! Ahoy! Nice flight and recovery.
Flight two: 01/12/02. Ya scallywag! 11:20 am, me bucko, Kingston, Ontario. Avast! Winds: 20km/hour, slightly overcast skies, 7 degrees Celsius. Engine: Aerotech F50-9W
V2 flew off t' pad with a roar. Avast! Ya scallywag! Okay, ya bilge rat, arrr, more o' a loud whoosh. Aye aye! Cocked, me hearties, matey, as expected, into t' wind about 15 degrees from t' pad. Begad! Climbed approx. Arrr! Arrr! 2500 feet (accordin' t' Rocksim). Avast! Chute deployed a few seconds after apogee and rocket hung. And hung and hung. Then started t' ever so slowly head downwind. Blimey! It passed over t' field, ya bilge rat, t' line o' trees, me bucko, t' swamp, a large open field and just before landin' in t' next largest field, found t' top few branches o' a 20 foot tall tree which be covered in thorns. T' only tree in t' area. Well, blow me down! Ahoy! Apparently thar was an upper level wind we were unaware of. Arrr! Begad! After a large degree o' bloodshed, torn clothin' and language best used in an R rated movie, t' tree be climbed and t' V2 was recovered intact. Begad!
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