Need help with CP for ACE Allegro Largo wedge-fin sim I want to fly tomorrow

Man I could use some help from one of you. Tomorrow I intend to fly my 4" Ace Allegro Largo with 3 X H class 38/360 sparkies. I have never simmed it because it is known design from back in the day but boy howdy does it seem tail heavy.

Nosecone 16" long exposed, AeroTech type. 57" of 4" paper airframe. 29.25" of the exposed 1.625" motor tubes (3 of em). Fins are 16" root, 15" leading, 5.5" trailing. The fin shape is a right triangle with the 90" angle between the leading and trailing edge. Fins are 5/16" thick, mounted 2" forward of the end of the MMTs.

All I need is quick and dirty CP calc so I can balance this and make sure it is stable.

Looks like this, but ignore his dimensions and use mine.

https://v-serv.com/usr/prototype/aceallegrolargo.htm

How does this look for a start?
View attachment ace.ork

Stable CG is just at the break to multiple tubes by my extremely rough sim.

To comfirm....stable CG is at junction of motor tubes and airframe? That is C G , not C P ?

J Blatz said:

To comfirm....stable CG is at junction of motor tubes and airframe? That is C G , not C P ?

Click to expand...

Yes. That's a very rough answer, so I'd give it a bit of a margin, but the bottom line is that.

Thank you for your help!