OK, I haven't done anything productive for the group lately. Here is my "beginners guide to bench trimming" customized for the SV-11.
This is not a replacement for the vastly superior Paul Walker trim chart, and is not meant to be complete in that respect. This is just a down and dirty beginners guide as it relates specifically to the SV "in my experience".
(Randy Smith is invited to comment where I go awry)
The SV-11 "in my experience" trims out well with the fore/aft CG anywhere between 3 1/4" and 3 5/8" behind the leading edge. 3 1/4" back is the "ultra stable" range, and 3 5/8" to 3/3/4" is "very sporty" and I wouldn't fly it further back than that.
Now, that is for standard Piped IC engines. I've seen Epower SV's trim out reasonably well at 3", and if they had used a normal rotation direction on the prop, I suspect the plane would have been stable with the CG moved back to my preferred range, which is 3 5/8".
If I was a beginner that was uncomfortable with high performance planes cornering ability, putting up my first ever flight on a new SV, I'd set the CG at 3 1/4", put the leadouts 1" behind that. Set the handle spacing at 3 3/4" to 4" at the handle. (standard Kaz style or similar hardpoint or cable, not front bar handles)
Next hang it from the leadouts and re-evaluate the fore/aft C/G making sure it's slightly nose down or at least level, not up, and check the vertical C/G making sure the wheels are parallel to the ground. Lighter or heavier wheels can help with this, but it's usually not far off if you stick to the stock design and is fairly forgiving.
Balance the plane on the spinner tip and the tail wheel, and make sure the outboard wing drops slowly but without hesitation. (about 1/2 to 5/8 ounce of tip weight in the long run for me most planes, but 3/4 to 1 ounce to start usually). This can be effected immensely by how long you make your leadouts before you cut/wrap/crimp them.
Roll the plane on the ground, make sure it rolls straight ahead. When you hook up your lines, make sure the handle is vertical (90 deg to ground) when the elevators are in line with the thrust line of the engine/wing/stab (not parallel to the ground!).
Do the flaps drop on their own and the controls work freely without binding or self centering? If not, fix it now, before you fly it! (springing back towards neutral is common after taping hingeline's, redo it until they are symmetrical without springing)
When you take off for the first time, take a step back and whip the plane off the ground just to be safe. Continue whipping the plane for the first lap. If all seems reasonable ok, relax.
Next, get a lap time. Shoot for 5.1 to 5.3 seconds to your personal taste and stick with it throughout the trimming process. Trim is SPEED SENSITIVE. Do not let your laps vary a lot from flight to flight during trimming, or you will chase your tail.
Now eyeball the wings and landing gear for 2 things, do you see one wheel in front of the other, and is the wing tipped towards or away from you? This is best confirmed by your flying buddies, make sure to tell them to watch closely before you take off.
If you are confident the plane is doing well, try some large inside loops. All ok? Plane didn't come in at you? Good. Try elongating the tops of the inside loops into hugely wide ovals. Tank seem OK? Not slowing down or speeding up drastically?
Try some lazy 8's next. Still OK? Engine hasn't quit, burped, or changed speed drastically yet? Line tension in the inside vs/ outside portion of the lazy 8 seem equal?
Good, now try inverted. This is where your buddy comes in handy, have him know ahead of time to keep paying attention, now he should be checking for wings level again.
OK, get it back upright and fly it out level. No need to try and show off or be able to brag how much of a pattern you did on the first flight.
When you land, make needed adjustments, and check ALL bolts, pull cowl, check engine bolts, check wheel play, etc. Button it up, you are ready for flight #2, and you will be the only one who really knows when it is ready to pattern. Refer to Paul's excellent trim chart from here forward and you should be golden.
Most importantly, breath, relax & bring it home in one piece!
EricV