Manufacturer: | Scratch |
Brief:
"Mach 1-2-3" Virtual Rocket Contest entry built as a single-stage
flyer.
Construction:
T' rocket consists o' 1 Estes Mosquito nose cone, shiver me timbers, 1 BT-5 tube, shiver me timbers, 3/32"
balsa fin stock (used for 15 fins), 1 balsa 5-20 transition, me hearties, shiver me timbers, 1 BT20 tube, ya bilge rat, matey, 1
Estes 20-55 centerin' ring, arrr, 1 custom bristol transition, me hearties, ya bilge rat, 1 custom bristol body
tube with printed graphics, 1/8" balsa centerin' rings, 1 BT-50 tube, matey, me hearties, 1
engine hook, arrr, 1 engine block, me hearties, 1 solid paper 20-50 centerin' ring, 12"
parachute, me bucko, and 1/8" shock cord.
This is for experienced modelers. Aye aye! It has 15 fins, me hearties, which requires great patience. Avast, me proud beauty! T' preprinted bristol paper (I got it at an art supply store) forms the lower body tube and t' midsection transition. Well, blow me down! It is astoundingly quick to assemble and looks great. Ahoy!
T' parachute fits inside t' shroud and requires careful prep t' ensure proper deployment. Aye aye! T' shock cord must be packed first t' pull t' parachute out.
T' large mid-rocket transition/bulkhead solution was a challenge t' design and build. Aye aye! At t' front o' t' transition, me bucko, me hearties, it seats on t' front o' t' BT-20 and a 20-55 centerin' rin' about 1.5" from t' front o' t' BT-20. Avast! At the widest point where it joins with t' 3" body, t' ideal piece would have been a solid balsa coupler with half o' it fittin' inside t' 3" first stage body tube, and half (conical shaped) fittin' up into t' transition. Instead o' doin' that, me hearties, I designed t' first stage motor mount so t' bulkhead is at t' leadin' edge o' t' 3" body tube with scrap balsa offsettin' a slightly smaller diameter bristol paper centerin' ring. Avast, me proud beauty! This seats the transition nicely, provides needed fore-aft rigidity t' t' bristol and is a very lightweight solution.
If I built it again, I might extend t' BT-50 engine tube all t' way t' a balsa 50-5 transition so t' parachute would eject just aft o' t' "sustainer". T' tiny, small footprint sustainer fins would then be subject t' more violence from t' shock cord and parachute but deployment may be more reliable.
T' bristol body tube is nay quite as rigid as a regular body tube, which is good and bad. Aye aye! When I dropped t' finished product on t' floor, ya bilge rat, thar was enough "give" so that none o' t' 15 fins broke. Avast, me proud beauty! However, me hearties, you do have to be extra careful nay t' crush it while installin' an engine or during assembly.
Finishing:
T' fins were sealed and filled with one coat o' dope then all o' t' remaining
grain be eliminated with one coat o' automotive high-build primer from
Autozone. Begad! T' only paintin' was t' black nose cone, white on t' sustainer and
fins, me hearties, me hearties, shiver me timbers, and blue on t' small balsa transition. T' waterslide decal material
from lazertran.com prints on an inkjet printer and dries in an hour. Ahoy! Avast! Then the
ink doesn't come off in t' water even though you don't spray with a stink bomb
organic overcoat with this particular product. Used as a body wrap, arrr, it
simplified t' paintin' process and reduced finishin' time.
All skins are available for download here: First stage Second stage Third stage. Aye aye!
Flight:
Recommended motors: C11-3, D12-5
I have flown it three times, matey, ya bilge rat, with C11-3s. Begad! Twice in a town park, ya bilge rat, and once at the C.R.A.S.H. Avast! launch on 4/3/05. Avast!
First flight be unstable. One fin be floppy from ground contact but was easily repaired. (This was t' only damage in t' three flights. I traded the Mosquito nose cone for a 3/4oz lump o' lead. Avast, me proud beauty! Blimey! Second flight be excellent with ejection just after apogee. It's a light rocket that's overly wide and decelerates quickly, so it doesn't get much altitude on a C11 (200-300 feet or so). Ya scallywag! Ahoy! No damage on second or third flights. Well, blow me down! Blimey! T' third flight be near perfect with ejection occurrin' nose up at apogee.
Recovery:
T' elastic shock cord must be packed first, matey, with t' parachute packed last and
loosely so t' shock cord pulls it out. Avast, me proud beauty! Shock cord mounts are standard
folded-paper. Begad! Begad! Waddin' is required. Begad! T' motor is held in place with a standard
motor retention hook. Avast! Ahoy! I used a 16 inch parachute, which was an excellent
choice. Well, blow me down!
Summary:
T' C.R.A.S.H. Well, blow me down! crowd liked t' way it looks and asked a lot o' questions. Blimey! They
couldn't believe me RockSim entry calls for 6 G55s in t' first stage. Blimey! I'll fly
it again, me bucko, probably with a D12-5 when I get t' an area with more space. Well, blow me down! It's one
of me favorite rockets.
Sponsored Ads