For those of you who might not be aware, in RockSim (I have 9.0), there is a way to change all your dimensions by a set factor. For example, if I have an Estes Alpha with a BT-50 body tube and I decide I want to upscale it to 6" Blue Tube, I can find the body tube sizes, make the division equation to find that my upscale is going to be a factor of 6.2285. If I already have the normal/original size Alpha in my RockSim, and I have Rocksim open to that drawing set, I go across the very top tool bar to Rocket, open the menu and go to the bottom and click on Scale. In the box I enter 6.2285, and enter, and immediately, all of my dimensions are immediately changed to the upscale dimensions. You can also reverse and downsize a larger bird. Then go to Save As, enter a new name and you have your new rocket plans, just about completed. I then change motor tubes, test fly it in the simulations and determine the motor size I want. It works great for me and for those of you who did not know, I hope this helps. 8)