In order to get the CG acceptably positioned in front of the 33” CP I had to add about 24 oz. of lead in the nose of my Loc Warlock. Ready to launch weight is now at 12lbs. 5 oz. (DMS J250W 54mm motor). This seems excessive to me….
Loc says that the CP on the Warlock is 33 inches from tip of nose cone. Without any added weight in the nose my CG was behind the CP. Anyway, I already epoxied the weight into the nose so now to go back to square one I will need to buy another nosecone from Loc and try and get a better handle on how to correctly sim. My intention was to try and do a Level 2 certification flight using this Warlock with a DMS J250W drilled to a 6 second delay and 3 grams of black powder for ejection (no electronics).....
J250 in a 12.5lb rocket is going to need more than 6 feet of guidance:
https://www.thrustcurve.org/motors/guide/62c1d38ff926ea0004177fe2/complete.html
The 12.4 m/s off the rail result, yes.Are you basing this off the "Slow off Guide" result?
The 12.4 m/s off the rail result, yes.
.5 cal with or without a base drag cone?I fly mine @ 0.5 cals of stability (based on OR), flies arrow straight!
.5 cal with or without a base drag cone?
I like Spherachutes. https://spherachutes.com/
Look at shape and placement of the fins on those two...Thank you for the information in this thread. I am finishing up a
4” LOC Phoenix and the LOC Goblin and was trying to rationalize why the Phoenix needs node weight and apparently the Goblin does not.
AWESOME chutes! Highly recommended!First time I've seen these! They seem to be reasonably priced, might have to give one a chance. Thanks for the link
I fly a Warloc with mid to large J motors and zero nose weight. The OP has made the very common mistake of thinking if RocSim (or Open Rocket) is not happy and I don't meet the rule of thumb (>= 1 caliber of stability) that nose weight must be added to the rocket until those conditions are met. Short fat rockets do not fit neatly into the generic rules for stability.
Most rockets that are military scale will need nose weight to be stable. Remember, they were designed to deliver a warhead, which is a nose weight.Look at shape and placement of the fins on those two...
Goblins fins are way at the aft end whereas the Phoenix fins extend quit a way forward.
This puts the CP of the Goblin fins back and the CP of the Phoenix fins forward.
They are also often guided and have a set of moveable fins.Most rockets that are military scale will need nose weight to be stable. Remember, they were designed to deliver a warhead, which is a nose weight.
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