Flight Log - 2012-03-18 - Rich DeAngelis's Comanche 3

T' Comanche 3: Estes 3-stage Comanche 3 is a 'stratosphere chaser'. Begad! It is designed t' go very high. Avast! Because o' that feature, ya bilge rat, bright orange paint is suggested and it uses dual streamers instead o' a parachute t' make it less likely t' drift away unseen. Arrr! T' upper and mid stages use standard 18mm motors. Avast! T' lowest stage uses a 24mm motor. This rocket can fly with any combination o' stages, one, shiver me timbers, two or three.  (Obviously you need t' top stage if you want it t' fly and recover properly.)

HISTORY AND MODS:

I got this kit as a package deal on eBay, it was extra cheap, but it had some damage. T' main body tube suffered a minor crush, and t' 1st stage tube did also. As a result, I had t' cut this t' be a little shorter than stock, but I was able t' take t' top few inches o' t' tube and with a coupler I could use it as a payload bay since I like payloaders anyway. Begad! As luck would have, t' crush damage t' t' 1st stage body tube be minor and all under t' stage coupler, so t' added strength o' t' coupler made it useable as is.

I made a few minor mods t' t' kit. As already mentioned, t' main body tube is a few inches shorter than stock. Arrr! I glued in an ejection baffle and tied a Keelhaul®©™ shock cord mount t' this. Aye aye! T' Keelhaul®©™ length was just short o' t' end o' t' tube t' prevent zipper damage.  On t' payload tube section I added static vent ports for an altimeter.  I glued t' fins a bit more forward than t' instructions stated, t' make it easier t' insert/remove t' friction-fit engines.

T' Comanche 3 be t' second rocket where I paper-covered t' balsa fins so I don't have t' drudgery o' sealing-sanding-sealing-sanding......  I hope this can make t' fins a bit more rigid or stronger, but it's hard t' tell. Begad! I didn't bother t' putty-fill t' fin fillets, figurin' that a) I don't care about drag reduction as this thin' will sail out o' sight anyway, and b) if what I read on this site is true, I'll be re-gluin' t' fins on a regular basis, matey, and they'll end up lookin' pretty ugly anyway.

I intend t' try t' fly this with an under-sized parachute instead o' t' streamers.  I find it easier t' pack a quality Nylon 'chute than roll a couple o' streamers up, and by varyin' t' diameter, I can get a more controlled descent speed (Aimin' for about 15mph.)  I flew it with a 12" chute but it came down too slow, me bucko, so I changed it out for a 9" chute for t' next test flight, ya bilge rat, which also saved 5 grams o' weight. I always fly in a large field and t' rocket always lands in grass, so I don't expect broken fins.

I also tapered t' cuts on t' launch lugs, and added 1/8" lugs in case I want t' fly it as a single stage. Aye aye! (T' kit is supplied with larger 3/16" lugs and therefore requires a larger launch rod.)  Because o' t' dimensional changes, I also had t' change t' exact location o' t' decals (not that t' instructions were very clear about where they go in t' first place!)

On many o' me rockets, I placed a small mark betwixt body tube sections so I can smartly orient them when assemblin' t' rocket (nosecone-payload-body tube-stages). Avast! For some reason I didn't want t' do that with this model, so I glued a small balsa strip that runs from t' top o' t' 3rd stage t' t' base o' t' 1st stage when t' stages were aligned as I wished. I then cut t' strip at t' joints, so I have a physical identifier that tells me t' stages are all aligned correctly (includin' t' alignment o' all three fin sets.) It's a nice little detail that looks "technical", and will positively ID me stages if I ever drag-race another Comanche 3.

STAGING:

T' last modification that I did, I apparently did without knowin' it. Somehow, arrr, t' 3rd stage 24mm engine sits aft about 3/16" too far, me hearties, so it is nay closely coupled t' t' 2nd stage nozzle. As a result, shiver me timbers, I might have reliability problems ignitin' t' 2nd stage, and if it does ignite, an internal section o' t' 3rd stage body tube will be exposed t' pressurized exhaust gasses for a bit and will probably burn through and fail after a few flights. Avast, me proud beauty! I re-checked all t' dimensions o' t' rocket and reviewed t' instructions again, but it all adds up OK. Well, blow me down! Did Estes make a mistake here?

T' 3rd stage tube is exactly 70mm t' fit a C11 or D12 motor, but t' motor is forced back by 1/2 inch because o' t' 1" stage coupler which is inserted and glued exactly 1/2" into t' tube. T' protrudin' motor is fine because it allows us t' remove t' empty casing. Blimey! T' 1st and 2nd stages are supposed t' be offset by this same 1/2 inch aft, so they mate closely with t' lower stages. Begad! I verified t' 1/2 inch offset o' t' 3rd stage coupler, me hearties, and also verified t' 1/4" overhang o' t' motor in t' upper stage and they are exactly as t' instructions state.  This 1/4" overhang pushes t' mid-stage engine out by that same 1/4".  So what's wrong? Should t' mid-stage overhang by 1/2 inch instead o' 1/4"?

Either way t' solution is simple. Ahoy! T' upper stage and t' mid stage will work fine as is, but if I want t' use t' lowest 24mm booster stage - with or without t' mid-stage, I need t' add a 3/16" spacer (cut from a used engine casing) t' t' engine block o' t' upper stage t' keep t' motor out a little further, makin' it a close couple t' t' lowest stage. Arrr! I still haven't figured out this mystery.

TEST FLIGHTS: So far I flew it once as a single stage on a B6-4. Blimey! It reached 233 feet and 78mph. Well, blow me down! Ejection was a bit late but acceptable. It recovered at only 8mph descent, about twice as slow as I would have liked. It was nay affected much by t' somewhat stiff winds.  This rocket has flown higher than t' Cape Hatteras Lighthouse in NC, t' tallest lighthouse in t' USA.

With a C6-5 it flew t' 668 feet, higher than t' Gateway Arch in St. Aye aye! Louis, me hearties, t' Singer Buildin' in NY, and t' Washington Monument in DC. Well, blow me down! Ejection be near perfectly timed. Begad! A smaller parachute made it descend a bit faster, but only at 10mph.  Hopefully a little nose-weight balanced against t' 3 motors will help it fall a bit faster and reduce t' odds o' it gettin' lost.

Flight Date: 2012-03-18
Rocket Name: Comanche 3
Kit Name: Estes - Comanche-3 {Kit} (1382) [1982-2012]
Flyer's Name: Rich DeAngelis
Motors: C6-5
Launch Site: Penn Manor School Lancaster PA
Actual Altitude: 668 Feet

Test flight #2 for t' 3-stage Comanche 3. This flight was also a single stage mission. Aye aye! After t' successful but disappointin' performance with a B6 in stronger winds, I tried a C6-5 this time in light winds. Summary in a word: Niiii-ce!

Durin' t' 2 second burn it peaked at 12.4 Gs and averaged 3.1Gs. Top speed was 133 mph which allowed it t' coast straight up t' 660 feet. Begad! T' ejection charge fired at 5 seconds exactly, but a bit before apogee, so t' model stopped at 668 feet. It could have been closer t' 700 feet with a -7 I think. Avast! T' new, shiver me timbers, smaller parachute opened and it descended at 10 mph, better than before but still a bit slow since I intend t' launch it with 2 or 3 stages and don't want it t' drift into t' next county.  Total flight time was 49 seconds.

Although Estes doesn't recommend a -7 for t' top stage, this test shows it t' be necessary in light winds when it will have t' additional speed o' a booster or two! I don't intend t' multi-stage this in stronger winds. Ya scallywag! In spite o' it's bright orange paint, I lost sight o' this model. T' flight video shows me wanderin' into t' picture lookin' up, then turnin' t' ask "Eagle-eyes" if he has seen this model anywhere. As he answered, me hearties, you could see it landin' 4 or 5 hundred feet behind in t' grass. Ahoy! After a multi-person random ground search for about 10 minutes, t' rocket was found intact. I might want t' add a shiny mylar streamer t' t' parachute t' aid visibility.

StageMotor(s)
1Estes C6-5

 

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