This post is being kept up to date as new information appears.
Origins and what "PNC-56" means:
This is a blow-molded polyethylene rounded-tip ogive nose cone shape of about 6.4" long, fitting Centuri ST-13 (and the equivalent Estes BT-56) paper body tubes. It appears to have originated at Centuri in 1976.
The Estes PNC-56 nose cone appears closely similar in shape and length to the Centuri PNC-136 #5466 as used in the UFO Invader (appeared 1976) and Phoenix Bird that had its debut in 1977. That nose cone was never listed in the parts section of the Centuri catalogs, but appeared on p. 10 of the 1980 catalog right next to the Phoenix Bird along with the ST-13 fin can F-413L #5467. The UFO Invader instructions clearly show that the nose cone was blow molded.
John Brohm's Estes Nose Cone reference v 10.1 (last updated circa 2005-2007) listed 4 separate variants for the "PNC-56A", described as blow molded. Brohm has no entry for a "PNC-56", though "PNC-56" was used by Estes in the #2029 Converter instructions, where it is cross referenced directly to PN 72013. I have not found any authoritative upstream online docs from Estes confirming the "A" suffix in "PNC-56A".
After additional research in December 2016 we now know of 5 different color variant PNC-56 versions, each with their own PN, plus an add-on helicopter rotor hub without a known PN that has been seen both as a user-assembled part and a factory-glued assembly. Finally there is a nose cone 4-pack that has been seen with different variants.
The Variants with their Numeric PNs
There are at least five different versions of the PNC-56, all molded in different colors. There is evidence for an additional orange color variant with the same PN as the yellow one.
P/N 072015, molded in black plastic(#2077 Sky Winder, #1262 Cosmic Cobra, #2130 Mach-12, #2128 Long Shot, #303164 nose cone 4-pack, #1465 Helicat). This PN is used both for the nose cone itself and an assembly with factory glued-on heli blade rotor hub.
P/N 072013, molded in yellow plastic (#1950 Eliminator, #2029 Converter, #1330 Challenger II, #1995 Helio Copter, #1440 Discovery). Also occurs with and without heli blade rotor hub.
P/N 060312, chrome plated over black plastic (#2168 Metalizer, #2180 Chrome Dome Silver), and over white plastic in #1417 Astrobee (photo later in this thread).
P/N 060340, gold plated over [probably black] plastic (#2181 Chrome Dome Gold)
P/N 072017, molded in dark blue plastic (#2091 Maniac, #2445 Splendor, #303164 nose cone 4-pack)
Conclusive data from primary sources indicate the the following corrections/additions to Brohm's list are needed:
- We have confirmed Estes usage of "PNC-56" (ref #2029 Converter instructions) but not for Brohm's term "PNC-56A".
- The NC for the #1330 Challenger II and #1995 Helio Copter is molded in yellow; Brohm fails to mark these. Ref. for Challenger II the 1982 Estes catalog pp 28-29 "No painting required with...yellow nose cone...". For Helio Copter, see elsewhere in this thread where Tramper Al posted a photo of a Helio Copter kit with yellow nose cone. Note that kit #1330 for the Challenger II has been re-used; it also refers to #1330 Free Fall. See later discussion about yellow/orange color variation*.
- PN 072015 is definitely the molded in black version. (Ref #1262 Cosmic Cobra instructions https://www.estesrockets.com/media/instructions/001262_COSMIC_COBRA.pdf and catalog photos)
- Neither the Long Shot nor Mach-12 instructions are available online. Use of a black molded cone in #2130 Long Shot was confirmed in https://www.rocketryforum.com/archive/index.php/t-62733.html by user 'snuggles' who reported the Long Shot had black nose cone and fins. At this point we have no confirmation on the Mach-12 type other than from Brohm.
- Brohm omits the #1440 Discovery for PN 072013. It was only available as part of a starter set (1987-1988 catalogs) that included a rocket with fin can and described as having a white tube and a "bright yellow nose cone". The instructions give no PNs. The Discovery was never sold separately from the starter set, making it a very scarce kit.
- The chrome version was plated over black plastic. Ref: I have one in my possession. It's unconfirmed whether the gold version was also plated over black plastic.
- The PN for the blue molded version comes courtesy of the #2445 Splendor instructions and the 2014 catalog that show it as blue. The Splendor was released after the last revision to Brohm.
- The PN 303164 "NC-56 Nose Cone (4 pk)" has variable contents. Documented examples include 4 identical black 072015 (Rocketarium site 2016), 3 black 072015 + 1 blue 072017 (photo elsewhere in this thread), and an all-black assortment of apparently differing shapes (Estes website 2016). Discount Rocketry's 2016 site explicitly says the contents vary. See further discussion below**
- There is an additional part - PN unknown - used with these nose cones that forms the blade attachment hub for the helicopter models #1995 Helio Copter and others***.
* Based on Tramper Al's post elsewhere in this thread, there may be color variations in the yellow molded PN 072013, which could stem from either manufacturing changes or aging effects. It's not known whether there was a different part number associated with the orangish variant. The 1980 Estes catalog describes the Challenger II as having a "yellow" nose cone; there are photos on this forum showing very yellow (Fishhead in the Challenger II gallery) and very orange (Tramper Al in this thread and Initiator001 in the gallery) nose cones.
** Estes currently sells an "NC-56 Nose Cone (4 pk)" as P/N 303164. The official Estes photo as of 2016 does not make it obvious that all 4 are the same type but does show that they are all black; the top one looks a bit different, but the description does not say "assortment". Nor does it give P/Ns for the cones themselves. There is a different photo of the NC-56 pack on Rocketarium in which they do all look identical. TRF user Tramper Al posted a photo later in this thread showing an older NC-56 4-pack with 3 cones in black and one in blue. Discount Rocketry says on their site "Note: the nose cone shapes vary from batch to batch...". Other vendors' descriptions use the word "assortment" and indicate that both 1-piece and 2-piece types were included. I am inclined to discount the latter because none of the blow molded cones were ever referred to as "2-piece", and think that some of that verbiage may have been copied from the official Estes descriptions of other nose cone assortments containing injection molded cones where it is true. Non PNC-56 shapes that may appear in the 4-pack have not been confirmed.
*** The Cosmic Cobra and Helicat instructions make it look like the blade rotor hub is an integral part of the nose cone, but in all available photos it's a separate glued-on injection molded part in black or white plastic (both colors documented by online photos). At some point Estes changed from furnishing the blade hub separately and having the builder glue it on to pre-gluing it onto the 072015 cone. This build page describes the DIY assembly of a Cosmic Cobra from the 2000s: https://www.seed-solutions.com/gregordy/Rockets/Cobra.htm
More recent kit instructions and photos of actual parts show the rotor hub is now factory-glued, but the 072015 PN is still used for the whole assembly (ref E2X Helicat instructions). To date no separate PN is known for this rotor hub. The #1995 Helio Copter [1988-1996] had a yellow PN 072013 cone with rotor hub. Though the Helio Copter instructions are not available online, there is a picture of an open-bag kit on Ebay that shows the hub was separate and also that the instructions did not have PNs.
See also this old TRF thread: https://www.rocketryforum.com/archive/index.php/t-17958.html
I have a vintage 2011 #2168 Metalizer with its P/N 060312 chrome plated NC over black plastic, which I measured as follows:
Main outside diameter at base: 1.346" = 34.2 mm (OR value: 34.18 mm)
Diam at 1.0" up from base: 1.346" = 34.2 mm
Diam at 2.0" up from base: 1.300" = 33.0 mm
Diam at 3.0" up from base: 1.160" = 29.5 mm
Diam at 4.0" up from base: 0.985" = 25.0 mm
Diam at 5.0" up from base: 0.731" = 18.6 mm
Diam at 6.0" up from base: 0.375" = 9.5 mm
Exposed length: 6.410" = 162.8 mm (OR value: 161.9 mm)
Diam of blunt tip section: 0.320" = 8.13 mm
Shoulder outside diameter: 1.289" = 32.75 mm (OR value: 33.0 mm)
Shoulder cylindrical section length: 0.620" = 15.75 mm (OR value for total shoulder length: 19.0 mm)
Shoulder cone section length parallel to axis: 0.363" = 9.2 mm
Shoulder cone section central hole diameter: 0.577" = 14.7 mm
Thickness of loop (transverse direction): 0.100" = 2.5 mm
Mass: 19.0 g (OR value: 17.0 g)
Wall thickness (value to make mass come out to 19.0 g with density of polyethylene HDPE)
This is all in good agreement with Cabernut's dimensions. The OpenRocket v15 mass is 2 grams too low, but its fundamental dimensions are OK. In my OpenRocket files I adjust the estimated plastic thickness to make the mass come out right, making the moments of inertia more realistic than if you use a mass override and omit the thickness.
OpenRocket Presets File Code
Here is the XML definition I've got now in my tricked out Estes component .orc file:
PNC-56 ref John Brohm Estes Nose Cone Reference List v10.1
Brohm calls this "PNC-56A" but I cannot find any upstream source for the "A" sufffix.
The only known usage of "PNC-56" is in the instructions for the #2029 Converter,
where it's cross-identified as a PN 72013.
Numeric PNs for "PNC-56" are as follows: (Note that Brohm's list is not correct in all respects)
072015 : molded in black plastic, #1262 Cosmic Cobra, #2077 Sky Winder, #2130 Mach-12, #2128 Long Shot.
Has separate heli blade attachment structure, molded in white or black.
Ref: Cosmic Cobra instructions, which (incorrectly) make it look like the NC has an
integrated heli blade hub (it's just factory-glued)
Ref: This Cosmic Cobra build page with photo showing the black NC and separate white heli hub:
Ref: TRF thread where user 'snuggles' confirms that the Long Shot had a black nose cone and fin can:
072013 : molded in yellow plastic, #1950 Eliminator, #2029 Converter, #1330 Challenger II, #1995 Helio Copter
Ref: Eliminator instructions
Ref: Converter instructions, where it's cross-listed as "PNC-56"
Ref: 1982 Estes catalog pp 28-29. Challenger II #1330 "No painting required with...yellow nose cone..."
So it is evidently a PN 072013; Brohm errs by not designating it as molded in yellow.
Ref: photo of Helio Copter kit with yellow NC and separate white heli blade hub posted to TRF at
Estes has used kit #1330 more than once:
Challenger II is #1330 in 1982 catalog, Estes site has #1330 instructions for the Free Fall
060312 : chrome plated over black plastic, #2168 Metalizer, #2180 Chrome Dome Silver.
Ref: Metalizer instructions https://www.estesrockets.com/media/instructions/002168_METALIZER.pdf
060340 : gold tone plated (black plastic?), #2181 Chrome Dome Gold
Ref: Chrome Dome instructions https://www.estesrockets.com/media/instructions/002181_Chrome_Domes_Gold.pdf
072017 : molded in blue plastic, #2091 Maniac, #2445 Splendor. Splendor instructions on Estes site give PN and the 2014 catalog gives blue color.
There is a PN 303164 "NC-56 Nose Cone (4 pk)" on the Estes site showing
black nose cones that look to not be identical. Discount Rocketry states
that the contents of PN 303164 change randomly among varaious shapes. To
date we don't have any information on the variants except that 3 black + 1 blue has been seen.
Physical data here was measured from a PN 060312 from a #2168 Metalizer, mass 19.0 g
<Description>Nose cone, plastic, PNC-56A, black, blow molded, PN 072015</Description>
<Material Type="BULK">Polyethylene, HDPE, bulk</Material>