Ye Olde Rocket Forum

Go Back   Ye Olde Rocket Forum > The Doctor is In! > Ask the Doctor
User Name
Password
Auctions Register FAQ Members List Calendar Today's Posts Search Mark Forums Read


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 05-12-2020, 11:24 AM
RobVG RobVG is offline
Craftsman
 
Join Date: Apr 2020
Location: Seattle
Posts: 103
Default Stability, the Swing Test, Openrocket and Temporary Fins Question.

The swing test has been criticized a few places on the Web. One example:

https://www.google.com/url?sa=t&sou...0QnIAte36ROImMo

In searching the forum, the swing test is common and frequently used here at YORF. How well has it served the members? Has there been false negatives and more importantly false positives regarding stability?

secondly, being a free program, is Openrocket reliable and trusted?

Finally, has anyone found a good way to temporarily mount fins incase changes must be made after testing.

PS building a DIY wind tunnel would be a fun project.

Thanks in advance
Reply With Quote
  #2  
Old 05-12-2020, 02:19 PM
joltinjoecanada joltinjoecanada is offline
Junior Rocketeer
 
Join Date: Mar 2020
Posts: 21
Default

I wouldn't move or otherwise adjust the fins after testing. I would just add nose weight.
Reply With Quote
  #3  
Old 05-12-2020, 02:52 PM
aeppel_cpm aeppel_cpm is offline
Ciderwright
 
Join Date: Apr 2013
Location: Burlington, WI
Posts: 633
Default

Openrocket is reliable - as far as it goes. You should understand the limits of modeling (simulating), and understand that the more complex the design, the less reliable the sim.

Creative people have put really complicated designs into OpenRocket. It spits out a stability number, but maybe not a good one.
__________________
Charles McGonegal
Ciderwright
AEppelTreow Winery & Distillery
Ad Astra Tabernamque!
Reply With Quote
  #4  
Old 05-12-2020, 03:52 PM
RobVG RobVG is offline
Craftsman
 
Join Date: Apr 2020
Location: Seattle
Posts: 103
Default

Thanks for the answers.
Reply With Quote
  #5  
Old 05-12-2020, 04:13 PM
Gus's Avatar
Gus Gus is offline
7/21/61
 
Join Date: Sep 2005
Location: North of Detroit
Posts: 2,223
Default

I routinely swing-test very short sustainers, 4.5" - 6" with very small fins, for my competition rockets. I have found it to be very useful.
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump



All times are GMT -5. The time now is 08:08 AM.


Powered by: vBulletin Version 3.0.7
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Ye Olde Rocket Shoppe © 1998-2024