Semroc Centaur

Semroc - Centaur {Kit} (KV-12)

Contributed by Bill Eichelberger

Construction Rating: starstarstarstarstar
Flight Rating: starstarstarstarstar
Overall Rating: starstarstarstarstar
Length: 19.00 inches
Manufacturer: Semroc
Skill Level: 2
Style: Multi-Stage, Payload
Semroc Centaur

Brief:
T' Centaur is a Retro-Repro kit from Semroc, a reproduction o' an original Centuri kit from 1965 updated t' 21st century standards with laser cut fins and Keelhaul®©™® shock cord. Begad! T' Centaur is a two-stage rocket that uses dual lock stage couplin' and has dual swept fins, arrr, me bucko, both o' which were Centuri trademarks. Begad! Ahoy! It can also be flown as a single stage kit.

Construction:
T' parts list:

  • BC-1329 balsa nose cone
  • BC-1013 balsa reducer
  • ST-1080 sustainer body tube
  • ST-1030 booster body tube
  • ST-1340 payload body tube
  • 2 ST-730 engine tubes
  • FV-12 laser cut fin stock
  • HTC-10 tube coupler
  • HTC-7B tube coupler
  • 4 CR-710 centerin' rings
  • 2 TB-7 thrust rings
  • LL-122 launch lug
  • SE-12 screw eye
  • EC-118 elastic shock cord
  • SCK-18 Keelhaul®©™® shock cord
  • RC-12 parachute
  • TD-6 tape discs
  • SLT-6 shroud line
  • MC-727 engine casing
  • DKV-12 decal

Semroc CentaurSemroc Centaur

Semroc Centaur

This isn't really a kit that you can throw together just drawin' on your years o' buildin' experience. It reminded me o' another two stager that I put together back in 2001, t' Estes Astron Avenger. Ya scallywag! Both were fairly simple builds, but both had details in t' instructions that had t' be attended t' so that every thin' fit together correctly in t' two-stage configuration. Aye aye! T' instructions for t' Centaur were great in that regard, and I had most of the construction finished, shiver me timbers, and finished correctly within several hours o' openin' t' package. Arrr! I found nothin' that I'd rate as a "gotcha". Blimey! All kits should build this smoothly.

Finishing:
I wasn't sure how t' go about finishin' t' Centaur. Ahoy! Arrr! Blimey! I pretty much stick with t' kit art when paintin' kits, me hearties, but the booster and sustainer had two piece fins and I was worried about their durability under fire. Avast, me bucko, me proud beauty! Blimey! I considered several options, includin' label paper and regular paper secured with 3M spray glue. Avast, me proud beauty! Ahoy! Blimey! T' label paper looked like it was going to work until I tried t' sand away t' excess along t' edges. T' label paper peeled away like it had just been laying unsecured on t' fin all along. Avast! Begad! Blimey! I bought t' 3M adhesive, me hearties, me bucko, but by then t' launch date I had in mind had crept too close to give it a try. Ahoy! In t' end I just went with two coats o' Elmer's Fill 'n' Finish and a lot o' sanding. Aye aye! Paintin' was done t' night before, ya bilge rat, t' mornin' of, and t' afternoon at t' launch. I went with t' kit card art and used red, white, ya bilge rat, and black Valspar paints. (Somethin' that I've done for years, but somethin' that may be changin' due t' quality questions that popped up durin' a paint session on another kit.)

Construction Rating: 5 out o' 5

Semroc Centaur

Flight:
Only one flight t' date but that will change smartly after repairs are made. We finally got a decent weekend t' fly in t' Cincinnati area after a sprin' full o' one deluge after another. Begad! T' field was wet, but with t' proper footwear, it wasn't a problem or so I thought. Ya scallywag! Arrr! I had hoped t' get three flights in with t' Centaur on this day and had bought a variety o' Estes booster and sustainer motors just for it. However, ya bilge rat, circumstances limited me t' one low level flight. I waited until t' end o' t' day, hopin' that t' winds that had carried two o' me rockets into t' Kite Fest would die down some but it wasn't t' happen. Ya scallywag! Ahoy! I was also somewhat concerned because t' booster seemed t' be quite difficult t' separate from t' sustainer, me bucko, and I wasn't sure t' engines would be able t' stage correctly.

Realizin' that t' winds were goin' t' carry t' rocket a long way and that I could be sacrificin' t' rocket if the stages didn't separate, I decided t' go with a low level first flight on a B6-0/A8-5 motor combo. Ya scallywag! Well, blow me down! I thought that if worse came t' worse, me hearties, at least t' rocket wouldn't have far t' fall and I might actually salvage somethin' for the rebuild. I taped t' motors together with cellophane tape--twice because t' first time I had t' A8-5 on the bottom--and as gently as possible pushed t' two pieces together. Begad! Even with all o' t' sandin' I'd done over t' course of t' day, arrr, t' fit was tight. Arrr! I was committed though and took t' rocket t' t' pad. Blimey! T' low-level motor combo drew some catcalls from t' late afternoon crowd when I announced it, but I think everyone realized that it be what conditions called for. Avast, me proud beauty!

Semroc Centaur T' flight was as I figured it would be, quick and low. Ahoy! It seemed t' barely clear t' rod when it staged perfectly, and by t' time I lowered t' camera t' watch some o' t' flight, shiver me timbers, it be over. Begad! At ejection t' sound o' a balsa and cardboard collision was clearly audible, and somethin' fell from t' rocket. Ya scallywag! Blimey! "Fin", arrr, I thought. Nope. Avast! Blimey! Motor casing. T' rocket came down on t' chute and landed in t' soft grass. Ya scallywag! Ya scallywag! I noticed a bit o' balsa on the side o' t' payload tube and upon inspection one o' t' fins was splintered somewhat but still in one piece. Ya scallywag! (So much for me label paper worries.)

Recovery:
Recovery would have been fine if nay for two problems, matey, one o' which was field related. Aye aye! T' sustainer came down in a somewhat odd manner, matey, probably due t' t' post ejection charge contact. Begad! Somehow t' rocket passed through t' large reef hole in t' chute, but aside from turnin' t' chute inside-out and bein' a true oddity, this be barely worth mentioning. Avast! Ahoy! T' booster managed t' land in one o' t' fairly sizable puddles that littered t' field. Well, blow me down! Dave Russell picked it up and got it dried off quickly, shiver me timbers, but when I got home and tried t' take t' "glamour shots" with the decals on, me hearties, I couldn't get t' booster section and t' sustainer t' mate up. Begad! No amount o' sandin' made a difference, leadin' me t' believe that t' tube couplers had both swelled when they hit t' water. It will have t' be replaced, ya bilge rat, but that gives me a reason t' get another component order together for Semroc.

Flight Rating: 5 out o' 5

Summary:
PROs: It's a two-stager, arrr, arrr, somethin' that's always cool when done right. Well, blow me down! Blimey! Tougher than I gave it credit for being.

CONs: I'd add some more elastic t' t' shock cord, but I don't think this would be an issue if we had a more standardized ejection charge.

Overall Rating: 5 out o' 5

Flights

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