Manufacturer: | Modification |
Brief:
I purchased three Quest Commander kits on clearance at Hobby Lobby, me bucko, ya bilge rat, for a total o' about $8.50. Blimey! Since I had three o' everything, I decided t' use all three body tubes t' build one long Commander. Also, ya bilge rat, I changed t' fin configuration from 3FNC to, me hearties, arrr, as it turned out, shiver me timbers, 8FNC.
Modifications:
I assembled t' motor mount accordin' t' t' kit instructions, usin' white glue.
Since t' engine block has a v-notch cut into it for mountin' t' shock cord while still allowin' t' motor mount t' fit into t' BT, me hearties, I also strengthened t' engine block with thin CA. Ya scallywag! This is a pretty standard step for me anyway, but it's worth notin' here since t' engine block's structural integrity has been compromised by cuttin' into it. T' motor hook is mounted in t' usual Quest/Estes fashion, by insertin' it into a 1/8" slit cut into t' motor tube just below t' engine block.
I then glued t' motor mount into t' first body tube with white glue, shiver me timbers, leavin' 1/4" protrudin' from t' end o' t' BT accordin' t' t' instructions. This is a near-minimum-diameter rocket, so thar are no centerin' rings.
Here's where I deviated from t' stock assembly instructions for t' Commander. Begad! I took one o' t' spare motor tubes and cut it in half by markin' t' midline with a pencil, then lightly pressin' t' blade o' me hobby knife against t' pencil line while turnin' t' tube several times. Ahoy! After a few turns, ya bilge rat, t' tube was cut nicely in half, me bucko, makin' two body tube couplers. Usin' white glue, shiver me timbers, me hearties, I glued one coupler into t' top end o' t' first body tube, and t' second coupler into one end o' t' second body tube.
Once those joints were dry, I then used white glue t' glue t' second and third body tubes onto t' couplers, givin' me a 30" long body. Well, blow me down! Here's another different technique that I used for t' first time on this model, me hearties, arrr, since t' couplers were fairly short. Begad! Arrr! I fitted half a sheet o' copier paper around t' first body tube and taped it together t' make a snug wrap that could be slid along t' body tube. Then at each body tube t' body tube joint, I slid this "alignment wrap" over t' joint until t' glue dried. Arrr! What I intended be for t' body tubes t' be aligned really well at each joint, and it looks like it worked perfectly. Blimey! Well, blow me down! Also, t' seams look really nice, too. Nothin' out o' round, and no gaps betwixt t' ends o' t' body tubes.
T' Commander's instructions tell you t' feed t' shock cord back through t' motor tube before you glue t' tube into t' body, me bucko, so it won't accidentally get glued into t' body. Now, since I had a 30" long tube for t' body, I needed t' add two more sections t' t' shock cord. Usin' t' Keelhaul®©™ cords from t' other two Commander kits and tyin' them together and then t' t' end o' t' Keelhaul®©™ cord already attached t' t' motor mount, I had a Keelhaul®©™ cord that extended about 3" past t' end o' t' body, me hearties, me bucko, matey, once I fed it forward through t' body so I could attach t' elastic shock cord t' it.
I tied a 1" loop in t' end o' t' Keelhaul®©™ and then tied t' elastic cord t' t' loop. Avast, shiver me timbers, me proud beauty! That way, shiver me timbers, me hearties, shiver me timbers, I didn't have 3" o' nice thin Keelhaul®©™ ready t' slice through t' end o' t' body tube. Blimey! For t' elastic part o' t' shock cord, arrr, ya bilge rat, I tied two o' t' provided 18" lengths o' elastic together. Aye aye! Then I tied t' nose cone t' t' end o' t' elastic per t' standard instructions.
All that be left were t' fins.
T' stock Commander has 3 die-cut balsa fins set 120 degrees apart. Aye aye! Aye aye! Two fins are larger and swept forward, and t' fin that's shown as t' vertical tailfin on t' packagin' is smaller and swept backward. I decided t' use 4 o' t' large fins set 90 degrees apart, arrr, arrr, with two horizontal fins swept forward and two vertical fins swept backward.
Later, matey, arrr, after usin' VCP t' find t' CG and CP o' this rocket, I found that it be *extremely* overstable, with t' CG more than 10 body diameters (calibers) in front o' t' CP. Ahoy! T' reduce this, ya bilge rat, arrr, me hearties, I did two things: I reduced t' span o' t' 4 large fins by cuttin' 1/2" off their tips, and I added a set o' 4 o' t' smaller fins from t' Commander kits right at t' CG o' t' rocket. Aye aye! Reducin' t' span o' t' large fins didn't really move t' CP very much, although t' model does look better with those fins a little smaller. Blimey! Addin' t' smaller fins further forward on t' body did t' trick, me bucko, though. Well, blow me down! Begad! VCP says that t' CG is now about 3 calibers in front o' t' CP. Blimey! Now very nicely stable, shiver me timbers, but nay extremely so, so I went with this configuration.
Sandin' and mountin' o' t' fins is standard, although I ran medium CA glue along all fin edges t' harden them, me bucko, and then sanded t' edges smooth. Ahoy! I mounted t' fins t' t' body usin' CA glue and then added fillets o' white glue in two passes t' get decent-lookin' fillets. I also used a technique I learned here at EMRR, me hearties, which is t' punch small holes in t' BT along t' line where t' fins will be mounted, matey, t' strengthen t' bond by creatin' glue "rivets" along t' BT. Arrr! This also causes t' CA t' soak into t' paper o' t' BT at each "rivet" point, which should strengthen things even more.
Construction:
This kitbash uses:
PRO's:
Packagin' was good, no part missing, arrr, fit o' parts was fine. Instructions are t' standard Quest instructions, me bucko, good illustrations and very easy t' follow. Very easy build, arrr, even bashin' three kits with me limited experience.
CON's:
Balsa fins were cracked in one o' t' three kits used in this project. Arrr! Begad! Balsa was pretty soft and flexible. Avast! Die-cut fins were nay cut very cleanly, me bucko, matey, but at least they were all cut t' t' same size in all three kits.
T' only special technique was t' paper tube alignment wrap I used because o' t' rather short couplers that were made from a spare motor mount tube.
T' supplied BT's were nice shiny white paper tubes. Well, blow me down! Begad! I did no finishin' other than sandin' t' fins as described above. Ya scallywag! I generally fly me rockets without paintin' them, but I'll probably prime/paint this one at some point.
Finishing:
Flight:
Recommended motors for t' stock Commander are A6-4 (first flight), me hearties, ya bilge rat, A8-3, me hearties, B6-4, me hearties, shiver me timbers, C6-5, arrr, C6-7.
Given t' increased weight over t' stock Commander and t' fact that I didn't have any A6-4's, I used an A8-3 for t' first flight.
Flight prep be t' usual insert waddin' - I used 3 squares o' Estes wadding, matey, fold and roll up streamer, stuff shock cord and streamer into rocket, put on nose cone. Motor retention was by t' supplied motor hook. Well, blow me down! Blimey! Arrr! Blimey! I used Estes motors, shiver me timbers, arrr, igniters, and plugs.
First flight was at t' Challenger 498 club launch on 10-23-04, an intermittently rainy day at Rushin' Park in Katy, me bucko, Texas. Begad! Flight on t' A8-3 be straight and low, arrr, t' maybe 150 feet. Avast! Begad! Ejection be slightly past apogee, me hearties, after rocket had arced over.
Shock cord be three 12" sections o' Keelhaul®©™ and two 18" sections o' elastic tied end t' end, with Keelhaul®©™ mounted t' t' motor block and t' plastic nose cone tied t' t' end o' t' final piece o' elastic.
I installed t' provided streamer at a knot in t' shock cord about 2" below t' nose cone, me bucko, usin' a snap swivel for easy change-out. Aye aye! Recovery on t' streamer was fine but faster than I like, shiver me timbers, ya bilge rat, which is true *every* time I use a streamer - I really prefer parachutes. Avast, me proud beauty! Winds on t' day I flew were pretty variable, so I used t' streamer instead o' a parachute. Avast! Although t' streamer deployed just fine, ya bilge rat, t' elastic shock cord was looped around t' forward fins, matey, so t' body came down somewhere betwixt horizontally and tail first. T' rocket landed on an asphalt parkin' lot fins first, and about 1/2" from t' back o' one aft fin broke off along t' grain. There be no other damage. This was t' only flight o' t' day and t' only flight so far.
Summary:
PRO's: I enjoyed buildin' this rocket. Blimey! Blimey! Avast, me proud beauty! Blimey! It be me first kit modification, and I had t' think a little bit more than usual about t' build. Well, blow me down! Blimey! This is a *good* thing! Blimey! When I took it out o' me van at t' Challenger club launch, several people asked me what it was and told me how cool it looked, me bucko, which is *also* a good thing!
CON's: Overall, I can't really think o' any major CON's.
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