Astrobee 350 fins "fix?"
 

Hello All,

Having had an original Semroc “Retro-Repro” Centuri Astrobee 350 kit (which the new Semroc also offers, see: http://www.erockets.biz/semroc-flyi...t-astrobee-350/ ), comparing it with the original Centuri kit (see: http://modelrocketbuilding.blogspot...erobee-350.html and http://modelrocketbuilding.blogspot...erobee-350.html ), it is obvious that the Semroc kit’s fins are—for whatever reason—down-scaled from the fins of the otherwise-identical Centuri Astrobee 350 (which Centuri also called “Aerobee 350”; here’s an older catalog view: http://www.ninfinger.org/rockets/ca...i68/68cen8.html [later, the kit was updated with a plastic nose cone, see: http://www.ninfinger.org/rockets/no...a/72cen022.html and <in a photograph> http://www.ninfinger.org/rockets/no...a/72cen012.html ]). Also:

Does anyone have a correct fin pattern (or dimensions) for the Centuri Astrobee 350 fins, that kit's body tube length (the Semroc kit, with its smaller fins, might [or might not] have a slightly longer body tube), and the Centuri part numbers of its balsa--and later, plastic--nose cones? The plastic nose cone of the Estes Dragonite (see: http://www.estesrockets.com/rockets...169-dragonitetm ) may be the same size and shape (plus, the Centuri Arcon and Arcon-Hi [and their Semroc reproductions] may use the same balsa nose cone as the Centuri & Semroc Astrobee 350; if so, the Dragonite's nose cone might be a plastic "drop-in" replacement for all three kits' balsa nose cones).

Many thanks in advance to anyone who can help!

I provided Carl with the dimensions for the Aerobes 350 fins and conduits. They were taken from my built vintage model.If I recall correctly, the fins were the same on both kits, its the angle of the photos that makes them look different.

The plastic cone was approximately a 5:1 ogive that fit a series 10 tube. This was the same one used on the Astro 1 kit. If I am not mistaken the Estes dragonite is HBT-90 a tube slightly larger than series 10.about 28+ mm in diameter.

If you do a search to Aerobee 350 on this forum you should come across our comparison of these two kits.

http://forums.rocketshoppe.com/show...hlight=Astrobee
Actually it was you , I and Carl. Oh well it has been about six years ago!

Whoa...I *feel* like that saying about Alzheimer's (which my morphine "simulates" in many ways)--"You can hide your own Easter eggs, and you meet new people every day..." I guess YORF is now, to an extent, my personal "cloud memory storage." :-) Thank you for directing me to the already-done research and the correct-size fin pattern scan! The discussion of the old Centuri launch pads and launch controllers in their current thread (see: http://www.oldrocketforum.com/showt...95&page=1&pp=10 ) included a couple of old catalog scans in which the Astrobee 350 (used as a 'launch pad model' rocket) was shown, and when I saw the Semroc Astrobee 350's too-small-looking fins (see: http://www.google.com/search?source...1.0.WWOqMT9J4xk ), it made me curious about the correct fin size--again. :-) Also:

The Dragonite's nose cone fits the ST-10 body tube (which is 1.04" in O.D. [Outside Diameter]; some of the Centuri catalogs give it as 1.0"). The Dragonite's body tube has--as the nose cone fit suggests, as I didn't measure it--the same I.D. (Inside Diameter) as ST-10, but it is thicker-walled than ST-10 (its O.D. is slightly greater, 1.1" [as opposed to 1.04" for ST-10]). That 0.03" smaller radius of the ST-10 tubing (0.06" smaller O.D., of course) would be swamped by differences of paint thickness (I wouldn't paint the bright Day-Glo red/orange Dragonite nose cone). Also--as I'd totally forgotten, but been reminded of, when I read the thread whose link you posted (to my surprise, the links that I'd posted in that old thread all still open!)--the booster of the Centuri (and now Semroc) Arcon-Hi was also made for use with the Astrobee (Aerobee) 350 and the Payloader II.