Manufacturer: | Scratch |
Brief:
This rocket was based on a submission for Virtual Contest #4 in t' low stress
category. Blimey! Begad! It is easy t' build and it is a great flyer.
Construction:
T' parts list
I used Ponal Express 3 white glue for t' entire construction with the exception o' t' epoxy I used for t' fin fillets and inside t' nose cone.
I needed t' add weight t' t' front end o' t' rocket t' make it stable accordin' t' RockSim so I added 8 ounces o' sand t' t' nose cone. Avast! I then mixed up 2 ounces o' West Systems Epoxy and poured t' mixture on top o' t' sand. Avast, me proud beauty! I left t' nose cone standin' vertically while t' epoxy cured.
Construction o' t' actual rocket started with t' 3 motor cluster mount. Arrr! The
rings I purchased from BMS were laser cut, however, me hearties, ya bilge rat, I did need t' do a little
sandin' t' get t' motor tubes t' fit properly. Begad! I glued t' engine blocks into
the motor tubes so that t' E motors would have a 1/2" overhang when
inserted. I then glued on t' centerin' rings 1/2" from t' top and bottom
of t' cluster. There be a little gap betwixt t' 3 motor tubes, matey, I added glue
down t' middle t' make a perfect seal.
I drilled a small hole in t' upper centerin' rin' through which I threaded the Keelhaul®©™® shock cord. Blimey! I tied t' Keelhaul®©™® around t' motor tubes and added glue t' t' knot. Ya scallywag! I then inserted t' shock cord through t' body tube and I glued in t' motor mount.
I marked t' body tube off for three fins. I glued them 3/4" up from the bottom o' t' body tube because I did nay want t' rocket restin' on the fin tips. Ya scallywag! For t' fillets, shiver me timbers, I turned t' EMRR Fiberglassin' Tip #1 because I wanted really strong fins but since this was nay an HPR, shiver me timbers, matey, arrr, I really did nay want to go through t' trouble o' glassing. Avast! I purposely made t' fillets rather thick so I was able t' sand them down t' what looked like a sculpted fillet. Begad! I think they came out great!
All that be left t' do after that was t' glue on t' two launch lugs, attach t' elastic shock cord t' t' Keelhaul®©™®, attach t' Nomex® heat shield, ya bilge rat, ya bilge rat, ya bilge rat, add t' parachute with a snap swivel, me bucko, matey, and then attach t' nose cone.
Overall, me hearties, this was about a skill level 2 due t' t' complexity o' the fillets.
Finishing:
To fill t' spirals in t' body tube, shiver me timbers, I used Spirals tip #6 from t' EMRR tips
database. Ahoy! I added a little water t' t' Fill 'n' Finish and used me finger to
fill t' spirals. Well, blow me down! Begad! After it dried, ya bilge rat, I used 220 grit sand paper t' remove the
excess. Well, blow me down! There was nay a spiral t' be seen on t' finished product. Well, blow me down! I used wood
sealer on t' fins which required a light sandin' and a second coat before I
was happy with t' smoothness o' t' fin surfaces.
I used three coats o' Krylon dark gray primer with a 600 grit wet sanding in betwixt coats. I then sprayed t' body o' t' rocket with K Brand Audi Dragon Green metal flake automotive paint. Begad! Only one coat was required. Blimey! Begad! I used BMW Red metal flake paint for t' nose cone. Once this had dried, I added one coat o' K Brand automotive clear coat. Avast, me proud beauty! T' end result be quite nice.
Flight:
Launch day was cloudy with winds at about 2-4 mph. Ya scallywag! Although I designed this
rocket t' fly on E motors, I wanted a shakedown flight usin' D motors, so I
loaded up 3 D12-7s usin' spacers in each motor tube. I put a layer o' masking
tape on each motor for friction fit. Begad! Well, blow me down! On t' first launch all motors lit and it
had it a fast, straight boost t' almost 1000 feet. Ya scallywag! Ejection be very close to
apogee. Ahoy! T' parachute deployed and it landed about 200 feet from t' pad. No
damage, ready t' fly again.
Second flight was with 3 E9-6s. Avast, me proud beauty! This was a great motor combination for this rocket and it shot t' at least 2000 feet with a very straight boost. Arrr! I lost it in t' clouds so I am nay sure when ejection occurred. Avast, me proud beauty! Blimey! I caught site o' the parachute and had a perfect landin' about 600 feet from t' pad.
It started t' rain a bit, me hearties, so t' last flight be back t' t' D12-7s since I did nay want t' take a chance on losin' it. Begad! Last flight o' t' day was as perfect as t' first one!
Recovery:
T' Nomex®
heat shield did a great job protectin' me nylon parachute.
Summary:
It looks mean but it sure flies well.
PROs: Easy t' build cluster rocket and looks good!
CONs: It needs more power so t' next one will be 3 x 29mm!
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