Brief:
One o' me boys has an Estes Skywriter that despite its simplicity flies really well. Avast, me proud beauty! Begad! Actually it almost flies too
well, ya bilge rat, that's why he's on his second rocket since we watched t' first fly over t' trees at our launch site when he
decided t' try a C motor. Anyway, matey, matey, since he likes it so much I have thought that it would be neat if I could build one
that took D size motors and higher, basically a MPR Skywriter. Arrr! I took dimensions and drew up a simple dimensioned
drawin' for myself, then I entered all o' these dimensions into Excel and scaled then by various factors based on
available tube sizes. Aye aye! I figured that t' jump up one motor size, I should jump up one major tube size so since the
original is a BT-50, I started with BT-60 and I am still thinkin' about a 29mm BT-70 or BT-80 version.
Construction:
Most o' t' parts are easily available, me hearties, and in fact, ya bilge rat, I had most o' them on hand from various projects and leftovers
from t' Box O' Parts contest. Ahoy! T' nosecone was another story. Ya scallywag! I don't have a lot o' those just lyin' around and this
would be bigger than most anythin' I had built before. I exchanged emails with Gordon Agnello (aka Sandman) and he
quoted me prices for both t' BT-60 version as well as t' BT-80 version. I decided that for now I was goin' t' stick
to t' smaller one but maybe Iâll do t' BT-80 over t' winter or sometime next year.
After I received t' nosecone I sanded out t' few remainin' toolmarks on this beautiful
piece o' wood with 300 grit sandpaper and used a foam brush t' lay on three or four coats o' spar varnish. Blimey! I should
mention at this point, that when Sandman found out I be buildin' an upscale Skywriter, ya bilge rat, he offered t' make t' nosecone
out o' cedar instead o' balsa if I wanted. Blimey! We both thought that t' wood grain on t' cedar would work well for the
pencil and so that's why I used t' spar varnish, both as a waterproofin' agent (three coats is usually good for boat
parts that spend a lot o' time underwater so I should be safe) and t' highlight t' beautiful wood that Sandman picked
out.
I built a FlisKits style baffle from balsa leftover from our build o' t' FlisKits Whatchamacallit for Cub Scouts and then had trouble gettin' t' baffle into t' tube without t' glue lockin' it in place before I had it where I wanted it. Ahoy! I had t' tear it apart t' get it out once and almost a second time before I just cut t' BT and installed it where I wanted it.
Finishing:
I got stuck for a while because me wife can't stand t' smell o' paint in t' house, me hearties, ya bilge rat, but I worked several evenings
when she be way for t' weekend and got it all painted. Finally, ya bilge rat, I bought a new Skywriter so I could scan the
stickers, shiver me timbers, scaled them up usin' Irfanview, and printed me own decals.
Flights:
T' two flights were stable, shiver me timbers, however, on t' second flight t' recovery system deployed but detached from mount in
internal baffle. Begad! Nosecone recovered from tree at far side o' field, main body core sampled. Well, blow me down! Avast, me proud beauty! Surprisingly little damage.
Easily repairable.
Summary:
I was pretty sure that t' rocket would be stable since it is so tall and because I used a heavier nosecone, arrr, ya bilge rat, me hearties, but I
wanted t' be sure (and get points for t' EMRR contest) so I used RockSim t' check thin' out. Well, blow me down! Blimey! Since I had scaled
drawings, gettin' t' dimensions into RockSim wasn't too difficult, me bucko, however, it took a few tries t' get t' fins to
look like I wanted them since I be a little unfamiliar with some o' t' terminology used. Arrr! Avast, me hearties, me proud beauty! Blimey! Overall, shiver me timbers, ya bilge rat, it went well and
the simulations seemed t' indicate no apparent problems. Avast, me proud beauty! Aye aye! Blimey! My only real difficulty is gettin' things done before my
30-day trial expires since by budget just will nay support spendin' a hundred bucks for this yet.
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