A few comments inline below.
ORIGINAL: Take2Flight
Thanks very much to all of you. I will PDF your advice and save it up for Mark 2!
A few comments:
1. David has me worried about the nose stability issue. I will cut into the cheek skin and reinforce it with hardwood or carbon.
That was my concern too. There really isn't much stiffness up front as there is nothing holding the sides square below or above. Your new 1/4" firewall is somewhat floating up there. Fortunately e-power doesn't produce much vibration but it can generate significant torque.
2. The AMA review cautioned against using a prop larger than 11'' on the Kaos because the gyro effect would cause tail wag on vertical lines. My goal is to replicate the stock piston performance, not necessarily to improve on it - on Mark 1 at least.
10" and 11" props are perfect for the Tower Kaos particularly on trike gear. A typical 40-46 glow setup.
3. The Firepower 40 is the only motor I could find on the planet which combines a 42mm diameter with 700W rating and low Kv (about 625 from bench tests). Nothing bigger than 42mm will front-mount in the nose of the Kaos.
There are motors on the market with 42 mm cans that can produce 700W and more. The low Kv is what you are
not looking for, at least not on classics. Low Kv is desired when one wants to turn big props with lower pitches. We can afford to lower the voltage slightly (i.e., 5s) at the expense of higher currents. The GP motor I mentioned has the sort of specs desired for 40 size classics.
4. The whole nose-mount thing began when I saw Franny Brodigan's gorgeous conversion of the Bridi Vagabond, which can be found in the link below. I thought I had to go nose-mount to imitate this. Now Franny is obviously a greater craftswoman than many of us guys can aspire to. So for Mark 2 I may have to hack out the nose for an X-mount instead.
http://www.frannybrodigan.com/Vagabond.asp
That's a beautiful Vagabond. The scheme reminds me of a little Tiporare I built - very nice.
However I'm puzzled. Franny didn't mount the motor like you did. You have the motor flipped 180 degrees with the stator behind your new FW and are using a shaft prop adapter. Franny mounted it like I was suggesting above using the X-mount with standoffs against the existing FW. Her prop adapter is mounted to the rotating can. This is a pretty bullet proof setup.
It wouldn't take much to flip your motor, mount it to the real FW and remove the ply up front. Pick up some aluminum or hard plastic standoffs. The latter you can cut to size easily.
Basically this type of installation is akin to a glow engine installed on a radial pylon type mount.
David