Welcome aboard Will. Hope you can get a zip file.
Let me know if this does not work and I can send you
the unzipped version of the 2 rotor 3dm.
I have many firewall forward examples done in Rhino that
I can share. Several have flown.
 Paul Lamar

Thank you Mr Lamar the file does work for me. Attached is a screengrab
with your motor positioned 14.62" (length of a RWS redrive) behind the
prop. That leaves about 7.6" between the back face of the engine and the
firewall or about 3.5" between the end of the shaft and the firewall. I
noticed that your model dosen't include the accessory drive package. How
wide is that? What is generally considered minimum distance between the
back of the engine and firewall? I will be ordering Tracy Cooks
conversion manual soon and I expect it will have that info.



Cool design.
Needs a lot more vertical fin.
Chris Cosman


Not counting the extension on the front of the fin, the rudder beneath
the horizontal stab, or the strake the tail gear is mounted to the
Vertical tail volume coefficient is .04 which is the value Raymer in his book suggests is historically a good number. A detailed stability and control analysis has not yet been done so it may change but for now I think i have enough.

Thanks,

Will

Will, I can send you a lot more part 3dm's in the next few days.

The RV4 pictures are of mine and you can cut those cheeks off with the rotary and cut the drag a bunch. The cooling system also fits under the cowl.

Paul Lamar