Wow, that looks almost conical. I would love to see that size by side with a pnc-55ac

Awesome!! Thanks Earl!

Confession time... I messed up on the decal recreation. I forgot that there are two large CG/CP markings on the sheet. Most people only use one of each, so it likely won't be an issue. However, I've edited them back in and replaced the image.

From the catalog image, I expected it to be a lot blunter on the tip... I've got a lot of updating to do on the balsa noseconed versions of the Cherokee-D to do (updated decals, corrected fins, nosecone, and double check the engine hook).

Earl,

Thanks for the image with the nosecone in the body tube. For those who don't know, it holds it straight, giving a better profile for photographic analysis.

I don't know if it's mentioned in the thread, but it has been discussed that the early BNC-55AC was not shaped the same as later ones, or the current PNC version. IIRC, the reason was that the tooling wore over time and wasn't replaced so the cones gradually morphed.

Hi Earl,

Working on the sim at this time...



I'm now quite sure that Estes did something really weird with the launch lugs and the standoffs on this kit... Taking your measurements of 1/16" x 1" long, there's no way that both LL Standoffs could be 5/8" long. If the rear is 5/8" long, that leaves only 3/8" for the front. I opted to go with that number as I can't see a way around it. The photo of the parts in the instructions also gives credence to the part you have being genuine. I also moved the forward LL back from the leading edge of the body tube based on the dotted lines seen in the instructions, as no specific location was given.

Could you check these numbers for me?

Instructions give the shock cord as "1/4" Shock Cord #SC-2" (which the 1974 Custom Parts Catalog gives as 1/4" x 18")

And the screw eye as "Screw Eye #SE-1"(which the Custom Parts Catalog doesn't list). I'm presuming it's 3/8" ID x 1" long.

Also, the parachute... Is it the yellow and red "Checkerboard" pattern with the old Estes Logo?

Unfortunately, the screw eye is missing from the kit. It and the launch lug. But, page one of the instruction set does call out the SE-1, which the 1970 Estes catalog says is one inch long weighing .04 oz.

Let me see if I can grab the kit real quick and get the info on the shock cord (it is quarter inch wide, I just don’t know how long) and the parachute...pretty sure it is the yellow and red, probably 18” and I’m pretty positive it has the pre-Damon logo.

I’ll edit this same post once I verify.

Earl

Edit: Ok, chute is 18”, yellow and red, pre-Damon logo. Shock cord is nominal 1/4 material 18.25” long. Will do the scans you mentioned via emai probably tomorrow sometime. Oh, and I reverified wooden dowel length: definitely 1” long. It does appear that Estes goofed on that material since that is not enough to put a full length of dowel under each length of launch lug fore and aft. If I were building this back in the day and were confronted with this, I would probably have cut the dowel exactly in half and centered that under each 5/8” length of launch lug...OR...I might have simply cut each launch lug piece to .5” to match the amount of dowel I had to put under it.

ELC

Thanks for the info!

I whipped up a couple of other versions for the LL for you to look at. Regrettably, I can't simulate the angle the instructions call for.


IMHO the 5/8" LL with centered 1/2" standoff is UGLY as sin (upper image)... The 1/2" LL on 1/2" standoff isn't bad at all (middle), and the 3/8" forward 5/8" rear version (lower) is what I had gone with, but I could be talked into the 1/2" version.

This looks close to the ARCAS scale drawing from Model Rocketry mag April 69...

I believe that the "AC" part of the BNC-55AC is a reference to the ARCAS rocket that inspired the part. Much like most of the two-lettered nosecones seem to match up with the kits that inspired the use of them them (ex. PNC-55EX (Exocet), PNC-55HJ (Honest John), etc.).

I suspect that the single lettered nosecones (PNC-50Y, PNC-55D) may just refer to a series of different shapes that were drawn and lettered, where the designers then chose the ones they liked.

Perhaps if a basic shape was liked, the person who drew it may have been asked to play with that shape and the new derived shapes kept the original letter and got a second letter. From there the best of those were picked (ex. PNC-55AO, PNC-60AH (though the AO, and AH are, I've been told, the same shape, just at different scales).

I guess someone could ask Vern, or any of the other surviving designers.

I'm thinking two 1" lugs on two 1/2" standoffs would look BEST.
PLENTY of "rail guidance" too.