The guppy shape of the fuselage is a major problem. She's rocking forward while under tow. This places the wing at a negative AOA, which maybe okay once she gets moving enough for the elevator to kick in.
When we were towing, I noticed the Fun-Cub was getting airborne first. I've seen this happen before & ordinarily its not ideal but that maybe exactly what's needed here. Once the tow-plane is up she'll be pulling up on the Cub's nose. That should in theory help get her un-glued from the ground. That's assuming the tow-plane doesn't stall out first.
I'm hoping the dolly will fix all this though. It should keep her at a nice neutral AOA & also reduce the rolling friction. I hate to rely on a dolly though. If I was to build a new fuselage (which I may consider but we're not at that point yet) here's what I'd do different...
A more forward position for the wheel should keep her from nosing over & help reduce friction. It looks like we'd also need a small tail-skid to keep the AOA from getting too extreme. Additionally, placing the tow-release up under the nose would reduce the tendency for her to rock forward. I have the release setup this way on one of my other aerotow gliders & it works well. Anyway that'd require major surgery, probably a whole new fuselage. I'm not giving up on the current setup just yet.
A guy over at RC Groups said they've been hand launching their gliders while aerotowing. My flying buddy Bernd suggested we try that but everyone at the field shot down the idea. I found this video showing that it is possible...
YouTube video, click to watch...
Hand Launch Aerotow
The sailplane in the video looks like a floater though, my Cub maybe a little too clunky. Maybe we'll give it a try though *shrug*.
So tomorrow we'll try the dolly & possibly a larger tow-plane this weekend. Onwards & upwards!