Oh Phill. That is such a shame. I'm spending so much build time on this rocket. I've built many over the last year or so, but this one is the most detailed. Especially with the vac wraps. I wish RocketryForum allowed me to upload pictures. I have a good looking Titan IV I finished and flew that I'd like to upload a picture to you. I tap the button to upload picture, choose upload from computer, pick the photo, hit upload file and nothing happens. The popup box just sits there. Very frustrating.
A few members mentioned inexperienced flyers, that's definately me. I think I'm still going to use the E12-4 on the rocket and hope for the best. I doubt this will be one of the rockets I fly over and over again. Max-Q's launch of his Saturn on the F-44 was beautiful. I have a couple of F-44 but have not found a large enough field where I live to use them. With the weight of the Saturn, and yes, mine will weigh much more than 12 oz with the extra glue (yellow and E6000) and multiple coats of paint and just inexperience. I have the free version of OpenRocket but do not have the skills yet to put the Saturn in to that program. I'm working on a Proton K now too and I just don't have the skills in OpenRocket to ad the 6 boosters (even though they are not boosters, but I'll call them that), tunnels, nozzels, clear fins, etc.
I do plan on weighing my Saturn when it's finished and finding were the CG is. I don't really know how to find the CP.
If yours will weigh more than 12 oz, then I think you should really look at a higher thrusting motor. And there are choices that fall between the E12 (which is probably too weak and might cause a crash), and the F44 (which might be too big for your field). You could try an E20 or E30.
You you don’t need a full simulation to get a good idea about motor choices. Try
https://www.thrustcurve.org/. Click on Motor Guide, and put in the info. For a 4” diameter rocket, 12 oz, 24mm mount, rough surface, the Aerotech E30 and F44 are readily available and recommended. The Aerotech E20 and Estes E30 are estimated to fail due to low speed off the rod, and the E12, D12, E9, etc. are even worse.
Of course, those are just estimates, and you can definitely get a good flight out of an underpowered rocket, in the right conditions. For one thing, the default rod length for the simulation is 3 feet, so if you have a sturdy 6-foot rod, you will have better speed off the rod and a better chance at a good flight. And, if you launch the rocket in perfectly calm conditions, with zero wind, and point the rod straight up, with no angle, you will also increase your odds for success.
You've invested a lot of effort and money in the rocket, so you don’t want to crash it! My recommendation would be at least an E20 motor, a 6-foot rod angled straight up, and zero wind.
