Manufacturer: | Scratch |
T' Blue Blade 3X is the
fourth in a series o' Blue Blades I've built. Avast! Begad! There were a total o' 4 with
various motor mount sizes, matey, shiver me timbers, a 13mm, 18mm, 24mm and t' 29mm 3X version.
Unfortunately t' 24mm siblin' is hangin' in a large tree at SMASH's launch
range.
T' 3X first flew on an F52-5 with a predicted altitude o' 708 feet. Arrr! Begad! T' F52 lifted her easily off t' pad and she climbed t' what I estimate be in t' 600 to 700 foot range, arched over and descended less than 100 feet where she deployed t' 24" chute. Well, blow me down! I would have started her out with a larger chute, but it was rather breezy, matey, me hearties, arrr, and t' field was a little soft. Avast! There was no damage.T' second flight was on a G64-7, which promised an altitude in t' 1300 foot range. Avast, me proud beauty! This flight was also picture perfect with deployment a little past apogee. Arrr!
T' Blue Blade 3X's next flight was at t' Three Oaks launch in November 1999. Ahoy! Ahoy! Bruce Kirchner graciously loaned me his 29mm-240 RMS for this attempt. Red Arrow be out o' me motor o' choice, an H128w, me bucko, so I went with an H238t. Luckily I had brought me set o' simulations with more than t' H128 and was confident o' t' motor selection.
I was feelin' just a little tense when t' Blue Thunder reload roared to life and t' next thin' I know she's streakin' skyward. Aye aye! Rocksim was predicting an altitude o' 1837 feet. I could just make out t' shape o' t' rocket against the clouds. I would have t' guess that it was a pretty close simulation. Ahoy! Avast, me proud beauty! The flight was successful and I now have t' L1 on me NARRRRR card.
T' motor mount tube and t' bulkhead in t' couplin' are designed t' function as an ejection baffle while incorporatin' an anti-zipper design.
Parts list;
These instructions are rather
brief and I am assumin' t' reader has some mid-power rocketry experience. Arrr!
First cut t' BT-3.00 t' t' correct lengths. I used a 6" long section of what was left t' fabricate t' coupling. Ahoy! (I had forgotten t' buy one at Red Arrow when I bought t' rest o' t' parts, me bucko, duh!) I split t' 6" section lengthwise and rolled it up and inserted it into a section o' tube. Avast! I marked the overlap on one end, ya bilge rat, then pushed it through t' t' other side and marked the opposite end. Ya scallywag! I cut t' excess tube away and epoxied t' tube back together and laid a piece o' scotch tape over t' outside joint t' cover t' epoxy. Blimey! Avast! I slid it back into a section o' tube and reinforced t' slit with t' section o' tube I had cut away. Be sure t' keep t' epoxy off t' OD o' t' coupling! Letting the epoxy cure with t' coupler in t' tube helped it keep a nice snug fit. Ahoy!
Drill 8, *" diameter holes equally spaced into t' *" bulkhead plate and one 3/16" diameter hole in t' center. Avast, me proud beauty! T' *" holes are on an approximate 1" radius. I attahced t' #10 eye bolt at this time t' give me somethin' t' hold onto when I epoxied t' bulkhead plate into one end o' the coupling. Begad! Ya scallywag! I positioned t' plate *" in from t' end and added a healthy fillet and small section o' glass cloth tape t' reinforce t' bulkhead to couplin' joint. Ahoy!
Drill t' holes in one centerin' rin' for t' "T" nuts and epoxy them in place. Begad! Begad! Mark t' 29mm MMT for t' centerin' rings, t' aft at 1/8" from t' end t' other at 6 5/16" from t' end. Begad! Make a 29mm/1.14" diameter x *" thick plywood bulkhead plate from some scrap. Coat one end with epoxy then epoxy this into one end o' t' MMT, coated face toward the motor end. I used a strip o' *" wide glass cloth electrical tape and epoxy to reinforce t' bulkhead. Well, blow me down! Avast! After t' epoxy cures drill t' 6 rows o' 6 *" diameter holes into t' bulkhead end o' t' MMT. Well, blow me down! Epoxy t' forward centering rin' so t' back surface is at t' 6 5/16" mark.
Mark one o' t' 3" body tubes with 6 fin guides. Aye aye! Ahoy! Blimey! Off set a mark 1/8" from each for t' fin slots. Ahoy! Well, blow me down! Blimey! Mark t' aft end o' t' slots 5/16" from t' tube end and t' other mark at 6 5/16". Well, blow me down! Aye aye! Blimey! Cut t' fin slots out. Avast, me proud beauty! Blimey! I used t' little saw attachment in me Ryobi multi-tool. Ahoy! Blimey!
Epoxy t' motor mount into t' slotted body tube so t' aft end o' t' MMT is flush with t' aft edge o' t' body tube. Avast! Well, blow me down! Cut out t' fins, shiver me timbers, match sand and round t' leadin' and trailin' edges. Avast! Make sure t' fin tabs match t' depth of the body tube t' MMT distance and sand t' fit. Well, blow me down! Epoxy t' fins in place adding internal fillets in you favorite manner. Avast, me proud beauty! Keep epoxy off t' aft edge o' t' fin tabs.
Epoxy t' aft centerin' rin' into t' body tube. Begad! I oriented the "T" nuts directly betwixt two o' t' fins. Ahoy! Avast, me proud beauty! I also glued in a scrap of 1/8" ply about 1" up inside t' body tube. Well, blow me down! I used this as a reinforced mountin' spot for t' Blacksky rail lug I would install lalter on. Be sure t' mark t' body tube location for later reference! Fillet t' fins as you normally would. Begad! Blimey! If you go with launch lugs attach them as you normally would. Well, blow me down!
For t' forward section o' t' 3X I simply epoxied t' nose cone into one end and t' transition into t' other. Seein' that t' attachment point o' the transition would be inaccessible after it be glued in, me hearties, I securely fastened a length o' 3/16" braided nylon cord t' t' transition. Avast! Blimey! I had a loop at the other end and t' length such that it extended past t' back o' t' upper 3" tube by a few inches. I attach one o' t' quick links and t' shock cord end t' t' loop. Aye aye! Blimey! Aye aye! Blimey! Another quick link attaches t' shock cord t' t' eyebolt of t' lower section. T' chute is attached t' a loop in t' shock cord 1/3 of the way along from t' lower section. This way t' rocket sections shouldn't smack each other on deployment. Avast! Blimey!
I pack t' chute into t' forward section behind about half o' t' shock cord first and follow it with t' remainin' shock cord. Aye aye! So far this method has worked well, as has t' baffle incorporated into t' couplin' and t' motor mount tube. Begad!
Rocksim gives t' Barrowman calculated CP location at 41.59 inches from the nose and t' Rocksim calculation CP at 43.35 inches from t' nose. Begad! I weighed out t' 3X at 963 grams less engine. Aye aye! Begad! T' Blue Blade's Rocksim file can be found in t' Rocksim library on t' Apogee Components web page. Ya scallywag!
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