View Single Post
  #4  
Old 10-06-2017, 07:26 PM
BEC's Avatar
BEC BEC is offline
Master Modeler
 
Join Date: Feb 2009
Location: Auburn, Washington
Posts: 3,643
Default

Jason,

No need to apologize. I kind of enjoy that sort of discussion, especially when I am able to go right to the source (Bill Simon in this case) and have him back my reasoning .

You referred to the fellow who has the 3D printed parts as "Raygun". I just relocated the thread on TRF I was thinking of and that was, in fact, the handle of the guy who was stuck on the idea that Larry Gregorek's measurements of built models that show up in TR-11 were "definitive". If you have nothing better to do, and you don't mind sullying your computer by going over there, here's that thread: http://www.rocketryforum.com/showth...ha-fin-pattern/

"Raygun" enters the discussion at post 61. He finally sort of admits defeat in the argument at post 113 after I took TR-11 and an SP-25 scan and asked Bill Simon, at NARCON in 2015, which he thought *defined* the fin shape.

I see that hasn't prevented him from claiming the TR-11 shape is definitive in his product description. To which I would say to all the other K-25 Alpha geeks out there "if you're looking for accuracy (as opposed to precision), buyer beware!"

I've since had the chance to get to know Bill Simon a little as we prepared for the recent 50th Anniversary of the Alpha affair at the Museum of Flight. I got to see some of his other design work when my wife and I spent a lovely afternoon and evening with Bill and his wife at their home a few weeks ago. I'm sure the original shape, drawn in 1965 as it turns out, was simply transferred to SP-25 by Gene Street and was reproduced from there in all the versions of SP-25 (including having it printed on the back of the yellow face cards in the 1970s) and the dies used to die cut Alpha (and Alpha II) fins during the period in which they were die cut.

Thanks for giving me an excuse to ramble a bit.....
__________________
Bernard Cawley
NAR 89040 L1 - Life Member
SAM 0061
AMA 42160
KG7AIE
Reply With Quote