There are at least 3 known versions of the Centuri BC-200 nose cone, based on your photo. There are possibly more. Our BC-2025 is based on one that I had on loan years ago that matches most of the catalog drawings. The drawings are not quite tangent (secant ellipse?) Our BC-2026 is based on a nose cone that I also had on loan that I thought was another version of the BC-200, but could have been from somewhere else, possibly FSI since they also had the 2.04" tube.

Your top photo (Gus) is obviously different from any cone I have seen and is possibly a third version of the BC-200. There are many variations of nose cones from Estes over the years from reshaping the grinding stones due to wear, but fewer from Centuri. This could be because Estes had roughly 4-5 times the volume over the "balsa years" from about 1963 to 1971 and had to reshape the stones more often.

We are working on the Egg Crate again and will use the catalog version (our BC-2025) on the production model. We sat the design aside years ago when Estes decided to release it in their Classic Series, but I understand that they will not be doing it in the foreseeable future.

__________________
Carl McLawhorn
NAR#4717 L2
semroc.com

Vanel graciously provided all the dimensions in this thread.

Carl,

Very interesting. I went back and read an earlier thread about the Egg Crate. Bill also had two different nosecones but in his case thought the more bulbous one was correct (the one to the left in the first picture below).

In my case, I know the black cone on the left in the second picture was actually part of a built original Egg Crate I purchased on ebay. The cone to the right (which looks a lot like the cone to the left in Bill's picture) I got in a box of old Centuri parts which also contained Egg Crate decals and fin sets.

So which is the "correct" cone shape, probably "both" is my best guess.

Attached Thumbnails

   

I vote for the one before the stone wore down.

Ok, we’ll take a bit of a step back into time here....

I was looking over some Egg Crate kits I have and Gus you are right: both versions of the two cones you picture above were used in the Centuri Egg Crate. My somewhat educated guess is that the more pointy cone was used in early Egg Crates (maybe summer through latter 1970) and the more rounded cone thereafter.

My clue on this is the shock cord attachment method used in the kit and the revision to that attatchment method during the run of the kit.

When originally introduced in the latter summer of 1970 (the 1971 catalog has an effective date of August, 1970), the kit used — and the instructions show — the ‘Mylar ring’ attachment method Centuri developed in the latter 60s for their kits. One sealed kit I have with the Mylar ring visible in the bag has the more pointy nose cone.

However, during approximately the late summer or early fall of 1970, Centuri introduced their self-adhesive backed, metallic foil/paper shock cord mount. One Egg Crate I have includes this latter attachment method (with a little instruction sheet printed addendum in the kit bag, which was included in many Centuri kits in the early 70s) that explained the new attachment method. THIS kit features the more rounded balsa cone and I suspect this kit was probably packaged in very late 1970 or sometime in the first half of 1971 before the Egg Crate was dropped before the 1972 catalog was being prepared, probably in the summer of 1971.

Earl

__________________
Earl L. Cagle, Jr.
NAR# 29523
TRA# 962
SAM# 73
Owner/Producer
Point 39 Productions

Rocket-Brained Since 1970

Earl,

Thanks for that great information!

Steve

Hey Steve,
Has it flown yet ??

__________________
When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, and HAVOC !

Oh for the love of Michael Jordan!!!

I only built it 14 years ago.

STOP RUSHING ME!!!

__________________
Bill Eichelberger
NAR 79563

http://wallyum.blogspot.com/

I miss being SAM 0058

Build floor: Centuri Design Contest F-150 Hurricane Estes - Low Boom SST Semroc - Marauder, Shrike, SST Shuttle

In paint: Canaroc Starfighter Scorpion Estes F-22 Air Superiority Fighter, Multi-Roc, Solar Sailer II Semroc Cyber III

Ready to fly: Estes - Solar Sailer II Semroc - Earmark, Groonie Der V 1/2

__________________
When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, and HAVOC !