Swing Test Attachment

So far I have never done a swing test. I have only build rockets from kits and used the motors they specified. (I trusted that the vendor knew what they were doing.)

The thing I have not seen addressed is how you attach the string. In a couple of my rockets when the motor is in place the CG is into the fin area of my rocket. And the thought of putting a hole in my rocket for this experiment has not been appealing.

Now I find myself at the point of wanting a bigger rocket with a wide range of motors. I have also noticed some of these give instructions to perform a swing test when trying a new motor. So at this point I either figure out how else to attach the string, or start learning/trusting some software.

1tree said:

So far I have never done a swing test. I have only build rockets from kits and used the motors they specified. (I trusted that the vendor knew what they were doing.)

The thing I have not seen addressed is how you attach the string. In a couple of my rockets when the motor is in place the CG is into the fin area of my rocket. And the thought of putting a hole in my rocket for this experiment has not been appealing.

Now I find myself at the point of wanting a bigger rocket with a wide range of motors. I have also noticed some of these give instructions to perform a swing test when trying a new motor. So at this point I either figure out how else to attach the string, or start learning/trusting some software.

Click to expand...

You'll find this extreamly useful: www.openrocket.sourceforge.net

and you'll find this extreamly helpful: www.rocketryforum.com/showthread.php?t=29767

see: post #20


Put the string away!

I would use string and blue painters tape. Wrap the string around the tube and tie a knot in it, move the loop to the CG, add some strips of tape to hold it in place.

bjphoenix said:

I would use string and blue painters tape. Wrap the string around the tube and tie a knot in it, move the loop to the CG, add some strips of tape to hold it in place.

Click to expand...

It has been a while since I have done a swing test, but that is exactly what I did.

The swing test is not perfect. Sometimes the rocket is stable, but refuses to swing properly. This happens a lot with longer rockets as it is difficult to get the rocket swinging in a large enough loop without risking damage from hitting the ground.