Before anybody complains,
I don't have much experience plotting model parts into Open Rocket. Still, I gave it a shot.
I took the RockSim simulation for the Sky Eagle off the Apogee website and dropped it into Open Rocket. I made a few small corrections based on the parts I had in the kit.
The engine mount tube is only 2 25" long and the kit did not have an engine block.
The engine hook does extend 3/4" out the back end of the fin can. I couldn't get the engine to extend the final 1/4" out the back. The above Sim is with an Estes A8-3 engine.
Enlarge the picture above and you can see the CG/CP are right on top of each other.
Below is the B6-4 simulation.
This is without the .30 oz. of clay nose weight I added and the engine moved 1/2" forward.
After adjustments, you should add .45 oz. of nose weight to get it stable with the heavier C6-5 engine. But - don't go by my results. Please do your own simulations.
A commercially available kit should fly stable without adding this much nose weight.
To change the motor overhang in OR, edit the motor tube; select the Motor tab; make sure "This component is a motor mount" is checked; then move the "Motor overhang" slider or type a number into the box.
ReplyDeleteThanks Rich,
DeleteI knew that adjustment was in there somewhere!
I'll try to slide the engine back. If the motor goes back to the end of the hook (as the kit is designed) that'll put the C/G even farther to the rear!