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tbzep
06-01-2008, 01:19 PM
When building my latest Alpha, I ordered a Semroc BNC-50K cone instead of fooling with turning my own. I noticed it was shaped significantly different from the PNC version that Estes uses today. I decided to order a couple of BNC-50K's from BMS since I was already getting some other stuff from them, just to compare nosecones. All three have different shapes that I thought you guys might like to know about if you haven't already noticed.

The Estes PNC version tapers fairly evenly all the way to the tip. The Semroc balsa version stays pretty fat for a considerable distance, then tapers sharply near the tip. The BMS version tapers more like the Estes Alpha III nosecone, including the rounded tip. Having never bought a 60's kit from Estes that used the BNC-50K, I don't know which is most like the original. Right now I have the Semroc version on the newest Alpha, but I've put the other two nosecones on it and they both make the rocket look considerably different.

http://i7.photobucket.com/albums/y283/tbzep/Rockets/DSC_0035b.jpg

http://i7.photobucket.com/albums/y283/tbzep/Rockets/DSC_0036.jpg

Doug Sams
06-01-2008, 03:34 PM
The Estes PNC version tapers fairly evenly all the way to the tip. The Semroc balsa version stays pretty fat for a considerable distance, then tapers sharply near the tip. The BMS version tapers more like the Estes Alpha III nosecone, including the rounded tip. Having never bought a 60's kit from Estes that used the BNC-50K, I don't know which is most like the original. Right now I have the Semroc version on the newest Alpha, but I've put the other two nosecones on it and they both make the rocket look considerably different. Tim,

The Semroc cone with the late taper is much like my 1969 kit's cone.
http://home.flash.net/~samily/old_alpha/alpha69-4-2-2.JPG

I seem to recall this being a topic (somewhere) a while back, and one vendor responding that they would make theirs more like the old one. Guess that was Carl, eh? :D (I had it in the back of my mind it was Bill @ BMS. I know, for example, he offers Bertha cones both in the current shape and the longer one of the 60's.)

I also have a couple of the rounded tip type from BMS. My attitude has alway been that I would sand some point into them should I use one on an Alpha clone.

Doug


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Mark II
06-01-2008, 05:52 PM
The PNC-50K cone was used on the Alpha III, and it was (is) more rounded than both the balsa cone used on the original Alpha and the plastic cone used on the current (#1225) model. Semroc has a BNC-50KA which matches the old Alpha cone, and a BNC-50KP which matches the Alpha III cone.

Correction: strike the italic text. See my next post.

Second correction: I was right the first time! Sheesh! :o Maybe I should just forget the whole thing.

Mark \\.

Mark II
06-01-2008, 06:06 PM
I seem to recall this being a topic (somewhere) a while back, and one vendor responding that they would make theirs more like the old one. Guess that was Carl, eh? :D

There was a discussion about this on the Yahoo! oldrockets group either last year or in 2006. I remember it, because it was related to my posts about my Maxi Alpha build. (Semroc also makes a BNC-80KA and a BNC-80KP to match, you guessed it, the cones used on the Maxi Alpha and the Maxi Alpha III, respectively. :D )

Also, I just checked their site, and I was wrong - Semroc only makes one version of the xNC-50K cone. It was their two (actually, three) BNC-80Kx versions that I was thinking about.

Wrong again! (Maybe I ought to just give up). I was right the first time! Jeesh! They have BNC50K and BNC-50KP. :o
(I had it in the back of my mind it was Bill @ BMS. I know, for example, he offers Bertha cones both in the current shape and the longer one of the 60's.)
That's good, no, wait, that's real good, to know!

Mark \\.
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scigs30
06-01-2008, 10:34 PM
One thing I have noticed with my vintage Estes rockets is that the balsa nose differs from kit to kit. I have 4 Goblin kits and none of the nose cones are identical. I think it has to do with the old style of of balsa grinder used to make the nose cones. Here are 2 pictures of my original Alpha builds with original Estes nose cones.

http://i89.photobucket.com/albums/k211/scigs30/100_2207.jpg
http://i89.photobucket.com/albums/k211/scigs30/100_2209-1.jpg

Mark II
06-02-2008, 12:42 AM
Are you sure that those vintage nose cones are from the same era? (Pre-Damon Alpha, early Damon-era balsa nose cone Alpha, late Damon-era balsa nose cone Alpha, late Damon-era plastic nose cone Alpha, current release (aka Tunick-era) plastic nose cone Alpha?)

I never had more than one of any kit, so I would not know if there was any variability in the shapes of the same model nose cone within the same era (or production run). But you can definitely see subtle changes in the shape of the xNC-50K over course of the 40 years that the Alpha has been produced. And there was also an entirely different nose cone made for the Alpha III (similar in size but different in shape). The later versions of the PNC-50K were both blunter and more pointed (is that a contradiction?) than the previous versions. (Compare the 1967 (http://www.ninfinger.org/%7Esven/rockets/catalogs/estes67/67est10.html) version with the 1994 (http://www.ninfinger.org/%7Esven/rockets/nostalgia/94est20.html) version, for example.) I can't say for sure when the nose cone on the model on the left in your photo was produced, [correction: I do have an idea, though - see Doug's post, or read on] but the one on the model on the right looks more like the one that came with the original K-25 kit, at least as it was shown in the 1967 catalog.

Here are a couple of (rather blurry - sorry) shots of my current model Alpha nose cone.

Tim, I think that you would have a vintage look with either the Semroc or the BMS version. The version shown on the middle model is a much more recent variation, though (it closely resembles the PNC-50K on my current version model). As Doug said, your Semroc cone resembles the one on his 1969 Alpha, so I think that the difference in shapes between the Semroc and BMS versions represents, at most, a couple of years' difference in vintage.

Mark \\.

tbzep
06-02-2008, 08:00 AM
Scigs30's cones are from two different kits, the Alpha and Alpha III, not two Alphas.

tbzep
06-02-2008, 08:20 AM
I'm going to try to make some sense of the timeline. I'm thinking that the original Alpha used a nosecone with the BNC-50K designation. A few years later, the Alpha III was introduced and its nosecone was designated the PNC-50K, even though it had a rounded tip. When Estes moved to a plastic Alpha nosecone, they had already used the PNC-50K designation, so they had to give the Alpha cone a new name, the PNC-50KA. Just like with other balsa-to-plastic conversions, there was a slightly different shape between the BNC-50K and the new PNC-50KA.

Later on we get Semroc and BMS who both produced BNC-50K cones, Semroc's similar to the Estes BNC-50K of old, and BMS similar to the PNC-50K. Semroc added a BNC-50KP which is similar to the Alpha III's PNC-50K.

The Alpha is an artist's rendering in the 60's catalogs and it shows a rounded tip. However, if you take a look at the fleet photo on the back cover of the 1966 catalog, you can see that the Alpha cone is pointed like the Semroc BNC-50K. Also, the Astron Cobra uses the same BNC-50K nosecone and the 1964 catalog shows a photo of the same shape as the pointed Semroc version.

I'm sure there have been subtle differences over the years due to wear and tear of the giant pencil trimmer/nosecone maker, but I think I have the Alpha nosecone lineage down pat now. :)

Royatl
06-02-2008, 09:33 AM
yes, there were slight variations with all Estes balsa cones due to the normal wear and tear on the grinders. The usual deformity was an increase in the OD at the shoulder, and was prevalent in Big Bertha and Alpha cones (presumably because they made more of them and therefore let the grinders go longer before replacing).

But this also showed up a lot on bt20 and bt5 noses.

Doug Sams
06-02-2008, 10:42 AM
I never had more than one of any kit, so I would not know if there was any variability in the shapes of the same model nose cone within the same era (or production run). yes, there were slight variations with all Estes balsa cones due to the normal wear and tear on the grinders. The usual deformity was an increase in the OD at the shoulder, I think, in some cases it was more than just wear and tear. I had one Streak that appeared to have been shipped with a Scout cone. At the time, I was too naive to notice (eg, see Alpha fins in previous post :D ) but in hindsight, I do recall having to sand the base to get it in the mylar tube, and having a noticeable step at the shoulder.

[Edit] I should add: While I'm sure it was sometimes accidental, I imagine it was deliberate at times as well. I'm not slamming them. Sometimes on-the-fly substitutions have to be made to keep the line moving. In most cases, it's not a big deal, and in my case, not even noticed :)

Doug


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scigs30
06-02-2008, 11:41 AM
My Alpha on the left is probably from the late 70's. I do have a Astron Drifter with the BNC-50K nose and it is pretty close to my 70's Alpha.

Mark II
06-03-2008, 12:21 AM
Scigs30's cones are from two different kits, the Alpha and Alpha III, not two Alphas.
:eek: Oops... :o

Mark \\.

Mark II
06-03-2008, 12:26 AM
I'm going to try to make some sense of the timeline. I'm thinking that the original Alpha used a nosecone with the BNC-50K designation. A few years later, the Alpha III was introduced and its nosecone was designated the PNC-50K, even though it had a rounded tip. When Estes moved to a plastic Alpha nosecone, they had already used the PNC-50K designation, so they had to give the Alpha cone a new name, the PNC-50KA. Just like with other balsa-to-plastic conversions, there was a slightly different shape between the BNC-50K and the new PNC-50KA.

Later on we get Semroc and BMS who both produced BNC-50K cones, Semroc's similar to the Estes BNC-50K of old, and BMS similar to the PNC-50K. Semroc added a BNC-50KP which is similar to the Alpha III's PNC-50K.

The Alpha is an artist's rendering in the 60's catalogs and it shows a rounded tip. However, if you take a look at the fleet photo on the back cover of the 1966 catalog, you can see that the Alpha cone is pointed like the Semroc BNC-50K. Also, the Astron Cobra uses the same BNC-50K nosecone and the 1964 catalog shows a photo of the same shape as the pointed Semroc version.

I'm sure there have been subtle differences over the years due to wear and tear of the giant pencil trimmer/nosecone maker, but I think I have the Alpha nosecone lineage down pat now. :)
Yeah, you're right. That's how I understand it, too. Sorry that I munged up the description and got my nose cones all confused - I must have been having a senior moment. :rolleyes:

Mark \\.

Quasar
01-17-2009, 01:00 PM
I'm a little late to this thread, but here's what I've found.

The NC on the left is a vintage BNC-50K. The one in the middle is obviously plastic and came out of an Alpha II kit (I also have one of these in an X-Ray kit). It's basically the same shape as the balsa 50K. The one on the right is the current plastic Alpha cone. Definitely not 50K shaped.

https://i.postimg.cc/tCztKHQ2/50K.jpg

tbzep
01-17-2009, 01:17 PM
I'm a little late to this thread, but here's what I've found.

The NC on the left is a vintage BNC-50K. The one in the middle is obviously plastic and came out of an Alpha II kit (I also have one of these in an X-Ray kit). It's basically the same shape as the balsa 50K. The one on the right is the current plastic Alpha cone. Definitely not 50K shaped.

http://webpages.charter.net/michaelsfields/50K.jpg

That's the first time I've seen the fat early BNC-50K look on a plastic nose cone. I wonder if it has a different part number than the regular shaped Alpha plastic cone.

Mark II
01-17-2009, 01:29 PM
The latest PNC-50K shape from Estes is the one that is actually a true ogive. The Alpha-III nose cone (PNC-50KP), OTOH, is an elliptical. Semroc calls the "classic" BNC-50K shape a "fat ogive" which sounds appropriate to me.

The Estes Phoenix nose cone, PNC-80K, which was also used on the Maxi Alpha, is not a true upscale of the Alpha's nose cone. At 8.2", it is too long. Semroc's BNC-50K is a faithful reproduction of the Estes PNC-80K, and it is an appropriate choice for use in a cloned version of the Phoenix or Maxi Alpha. The build a true upscale of the K-25 Estes Alpha, use Semroc's BNC-80KA instead. To build a clone of the Estes Maxi Alpha-III (or, presumably, a true upscale of the K-56 Alpha-III), you can use Semroc's BNC-80KP.

Mark \\.

Quasar
01-17-2009, 10:50 PM
That's the first time I've seen the fat early BNC-50K look on a plastic nose cone. I wonder if it has a different part number than the regular shaped Alpha plastic cone.

I'm afraid I can't help you there. Both the Alpha II and X-Ray kit instructions I have list a balsa nose cone with part # 70262.