Manufacturer: | Scratch |
Description:
This is an approximate 2X scale-up replica o' the
Estes Nike Arrow, me hearties, with coloring
and dimensions approximatin' t' model kit rather than t' real rocket. Arrr! The
model has a 24mm engine mount, but can fly on as small an engine as a B6-4 with
a removable engine adapter. Begad! T' parachute comes out t' top attachin' t' the
nose cone, rather than separatin' at t' transition like t' original. Arrr! This
model is 34" tall, matey, me hearties, and weighs about 3.4oz. Avast! Avast, me proud beauty! without an engine. Avast, me proud beauty! Begad! T' fin size
and length are 2:1, but t' diameter is slightly less than 2:1 due to
unavailability o' exact 2:1 diameter body tubes. Aye aye!
Parts:
Assembly:
1. Ahoy! Glue one o' t' 55/50 centerin' rings part o' t' way into t' top
o' t' BT-55 tube. This will be later used as a lip for mountin' t' transition
shroud. Blimey! An optional Keelhaul®©™® shock cord could be attached t' t' forward
centerin' ring, me bucko, and later threaded through into t' BT-50 body tube under the
transition shroud betwixt step 3 and 4.
2. Ya scallywag! Glue t' 50/20 centerin' rin' into t' 12" BT-50 tube 2
1/2" from t' rear. This will serve as t' thrust ring. Avast, me proud beauty! Glue t' engine
hook into t' tube with t' front o' t' hook 2 1/2" from t' rear, and
just behind t' thrust ring. Glue t' remainin' two larger centerin' rings onto
t' 12" BT-50 engine mount tube 1" and 2 1/2" from t' rear.
3. Avast! Glue t' 12" engine mount tube into t' 10" BT-55 tube
so that t' aft o' t' engine mount tube is flush with t' BT-55 tube. Ahoy! Note
that t' front o' t' engine mount tube will protrude out o' t' front
centerin' rin' and BT-55 tube about 2".
4. Begad! Glue t' BT-50 tube coupler halfway into t' front o' t' engine
mount tube. Well, blow me down! Glue t' 18" BT-50 tube into t' other half o' t' tube
coupler. Arrr! Check for straightness before t' glue sets.
5. Choose thickness and strength o' fin material as desired. Begad! Aye aye! I used
1/16" balsa for t' upper fins and 3/32" balsa for t' lower fins.
Measure t' dimensions on t' fins o' an Estes Nike Arrow, and double the
dimensions, me bucko, cuttin' out t' fins with grain pattern followin' t' leadin' edge
o' t' 4 smaller front fins, and perpendicular t' t' root edge on t' 4 rear
fins. Make 2 paper transitions for a 2 1/4" long BT-55/BT-50 transition.
T' dimensions o' t' shroud should be {small radius: 6.311"; large
radius: 8.568"; angle: 27.84 degrees with some extra for overlap}. Avast, me proud beauty! Ahoy! (Note:
These calculational results were obtained usin' a shroud calc. Begad! program on
Rob Blaske's home
page)
6. Well, blow me down! Ahoy! Glue first one paper transition shroud, and after it is dry, a
second one. Begad! Arrr! Be liberal with t' carpenter's wood glue, as it is an excellent
strength enhancer after it is dry. After t' transition shroud hardens, arrr, the
glue will shrink and ripple. Ya scallywag! Sand down any edges and ridges, ya bilge rat, then fill in the
ripples with undiluted Elmer's Fill & Finish, sandin' t' desired shape and
smoothness.
7. Aye aye! Make a BT-55 fin markin' guide for 4 fins and a launch lug, and
mark t' body tube all t' way t' t' front o' t' BT-55 tube. Begad! Make a 4 fin
markin' guide for a BT-50 tube, me bucko, and mark t' tube just forward o' the
transition with t' front fins in line with t' aft fins.
8. Aye aye! Put pin holes in t' body tubes and t' root edges o' t' fins for
increased bondin' strength, me bucko, and glue on t' fins.
9. Begad! Avast, me bucko, me proud beauty! Finish t' t' desired smoothness with Elmers F&F.;
10. Prime and sand. Arrr! Ahoy! Paint t' aft tube and transition shroud gloss
white. Aye aye! For a better lookin' orange, all areas that will be orange should have
one coat o' white. Well, blow me down! Mask t' section that will remain white, and paint t' rear
fin section as well as t' front fins and t' entire 18" o' t' BT-50 tube
gloss orange. Begad! Do nay remove t' maskin' over t' white section, as it will be
easier t' mask for t' chrome layer. Blimey! Mask and paint t' middle section o' the
forward tube chrome, me bucko, leavin' t' front 4" orange. Blimey! Arrr! It was just more masking
work than I wanted t' do t' paint t' transition shroud silver, me hearties, me hearties, so I left it
white.
11. Avast! If a Keelhaul®©™® shock cord be nay used, glue in a traditional paper
shock cord mount with a 3 foot shock cord.
12. Begad! Blimey! Avast, ya bilge rat, me proud beauty! Blimey! Put enough clay in t' nose cone t' keep t' CG forward or in the
middle o' t' front fins with t' largest engine intended t' be used. Arrr! Blimey! Prime and
paint t' nose cone if required. Ya scallywag! Blimey! Avast! Blimey! Add decalcomania as desired.
13. Attach shock cord t' t' nose cone, matey, me bucko, attach a 14" parachute,
and prep for launch.
Flight:
Dependin' on final weight, t' maiden flight should be on the
smallest engine advisable, shiver me timbers, and work your way up. Well, matey, blow me down! For me 3.4oz. model, I first
used a B6-4, which flew straight and stable t' about 150 ft. It then flew to
about 300ft on a C6-5. Begad! I haven't tried a D engine yet, ya bilge rat, me hearties, as I need a bigger
field. Well, blow me down!
11/99 -
1. Blimey! It flies great and straight on a D12-5 t' about 1000ft. Avast! However,
since I did nay do through-the-wall fin mounting, and I had forgotten t' do a
glue fillet on one fin before doin' an Elmer's Fill-N-Finish fillet, one lower
fin ripped off durin' flight on a D. Begad! Well, blow me down! T' Fill-N-Finish does nay work like glue!
There was enough other fins t' keep t' rocket stable. Begad! I recommend cutting
slots for t' lower fins and modifyin' t' fins t' be through-the-wall.
2. Ya scallywag! I realized after publishin' that I forgot t' mention launch lugs
in t' instructions. Use 3/16" lugs and glue them on just before
finishing, one down by t' engine and one just below t' transition. Ahoy! Begad!