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