The images below show the setup for this. Make a copy of the Ultimate, and then click edit. Pick an electric motor (any one will work since this is getting made using the automatic Scaling Wizard stuff). Then pick sounds. I picked the one that has a audible sound range from 1700 to 9000 rpm. Then in the scaling tab, set the wingspan to 40 inches. On the other scaling tab, set the max prop rpm (I tuned this to feel like a thrust-to-weight ratio around 2). I let it autoscale the prop, but you can input the prop diameter to be what you want. If you do this and leave the prop weight unchanged (zero), it will autoscale the prop mass properties.

It reminds me of a twitchy small gas biplane that I had once before and crashed promptly.

Michael