After retiring I found Openrocket and have been enjoying rocket design and scratch building. I have learned more doing this and reading the Rocketry Handbook than I ever did building kits. There is more to the story but I didn’t want my post to look like the dead sea scrolls, so I will get to my question. My friend built the Estes super big bertha but he weighed it and it came out 2 ounces heavy. I told him I would check it out in Openrocket to see how it looked. I downloaded the file for the Estes super big bertha (a rocksim file) and opened it in Openrocket. I played with the Mass override until I got the C/G and weight correct. It showed the CP at 26.18” with the stability down to .797 after adding weight and getting the C/G correct. I then looked on some web sites and found the listed CP was listed at 28”, that’s almost 2” difference. I know this could get into a lot of questions but given weight and CG will effect the rockets stability it won’t change the CP. So simply put do I believe Openrocket or data listed on the spec in ads (assumed it was provided by Estes) as far at the CP location. All my designs are not kits and I hope I can still trust openrockets CP location. I’m in danger of rambling on so I will quit here. So, what do I believe?
Thanks
steve
Thanks
steve