fins on OpenRocket

[bobby_hamill]

I am trying to sim out my project and when I try to do a free form fin by import from image option the fin is way to big for the airframe
Do I half to set up the fin image just like the same way when doing a decal wrap on the airframe ?

BTW that is a 3.9 inch diameter airframe the fin is attached to

Attached is a image of what happens

Thanks !

Bobby

 

[K'Tesh]

There's a Tutorial for that... (for the whole process... check this out.)

And a link to all of my OR tutorials: https://www.rocketryforum.com/showthread.php?62884-K-Tesh-s-OpenRocket-Tutorials

Typically fins imported from images appear to be HUGE on the rocket, so you need to scale it from what it is to what it should be. This also changes the thickness of the fin. So, you'll need to correct that when you get done.

 

[MikeyDSlagle]

Yeah. What he said.

An easy way to scale: Use a simple measurement, the root cord is usually best because it is easy to tell what the length is on the oversized fin, in this case around 14" (on my Kindle so I can't really tell). Go to the window to edit your fin shape. Toward hhe bottom is a "Scale" tab. Click that and you'll have a couple of boxes. One box should be "from", the other "to". In the "from" box put the root chord length of your oversized fin (14") and in the "to" box put the number you want it to be. It'll scale the whole fin.
Then, like K'Tesh mentioned, double check thickness and weight. Easy peasy.

 

[bobby_hamill]

Thanks guys for the help.
I have since bookmarked the OR tutorials from K'Tesh
Good stuff !

Bobby