View Single Post
  #56  
Old 01-18-2020, 06:38 PM
Vanel Vanel is offline
Master Modeler
 
Join Date: Jun 2005
Posts: 735
Default

Quote:
Originally Posted by astronwolf
It's not conjecture. NAR and FAI contest fliers have tested motors on test stands over the years, and that's where our anecdotal information comes from. But no one has published the data AFAIK.


This is interesting - I have a test stand I put together using equipment from Vernier, and have used it to successfully test a few motors. So I went to my motor stash and pulled out the following B6-4's:

Date code Weight (grams)
8 12 69 16.59 (also has a greater nozzle diameter)
17F5 (5/17/75) 18.23
19K5 (5/19/80) 17.81
15W5 (5/15/92) 18.36
A052703 (5/27/03) 17.76
B180918 (9/18/18) 19.00

I have dug out the test equipment and hope to do the tests this coming weekend, weather permitting. I then will post the thrust curves for scrutiny.

The attached shows a nozzle comparison, with the 1969 B6-4 on the left.
Attached Thumbnails
Click image for larger version

Name:  IMG_6792.jpg
Views: 29
Size:  437.2 KB  
__________________
Up next:
Under construction: Estes Olympus
Under repair:
In finishing:
In primer:
In paint:
Ready for decals:

Bill Cooke
NAR #31312
TRA #19705
SAM #0001
Huntsville, AL

My rocket blog
My rocket fleet
Reply With Quote