Wingspam

I need a little help, lets make that a lot of help. I recently purchased this Modified Force one from my local hobby store. I call it modified because it does not look like any other pics of a Force one I have seen. I went to Balsa Usa's site to look at there Cg suggestion for this plane it is 13" from the trailing edge(not including control surface). I then found crazy's Herbs cg calculator and used it, it showed to be at 14". So i split the difference. I made a hatch just above the landing gear for the battery.

Powered with an Os 55ax w/ a 10x8 pusher, with fuel it weighes 6.9 Lbs. I took it too the field today for its maiden flight for the new owner (Me). I taxied it up and down the field at 1/4 throttle just to get the feel of it, i did this twice. I pointed her nose into a very mild wind using about 3/4 of the run way. At about half throttle, before the nose wheel even lifted off the ground, the plane made a hard roll to the right and landed upside down breaking a fin.

Can anyone explain how and why this happened? And how I can correct it..

Thanks

Wingspam

Orginally I was thinking it might have been the lateral balance, but is slightly heavy on left side about 2 oz.
Could it be that it is way to tail heavy?

THanks

Wingspam

Hmmm This one must have you all stumped.

Could the torque of the motor cause it to roll to the right like it did?
The exhaust is routed thru the wing, is it even possible that the exhaust could have contributed to the rolling to the right?

This one has me beat.

BadSplice

My Feedback: (1)

Actually I am a bit stumped, but Im sure its not the exhaust causing the problem. I did the exact thing on a Nitro Models Kangaroo, with no ill effects.

2 thoughts I had... it could be that the landing gear makes the plane sit with the nose too high, so it starts to lift too early and stalls....

Or, check to make sure the ailerons are reversed. If they are, it feels like it just flips over, cause as you see it start to roll a bit, you correct, and it just rolls more.

If the ailerons are going the right way, I would try holding some down elevator until the plane builds up more speed on the takeoff run.

airbusdrvr

I have several delta planes. Does the nose of the plane sits as high on the ground as it appears in your picture of it sitting on the table? If so, I would think the nose up attitude could cause the plane to lift from the runway before it has flying speed. Both of my glow powered deltas sit with just a few degrees nose up on the ground. They do not lift off on their own and take a pilot input for rotation to lift off.

If the plane was a kit build, check as best you can that the wing looks straight with no warp. The elevons at neutral control stick should be very near symetrically positioned. Usually a delta wing will have a slightly up elevon positioning at neutral. You can eyeball the wing chord from the side and the elevon on that side will be slightly trailing edge up from that line. CG is more critical for a delta. Better a bit nose heavy than tail heavy.

Hope this hasn't been to rambling. Just trying to give you some thoughts for the delta wing.

Wingspam

Thanks for your suggestions

I will lower the nose gear and move the battery forward a few inches..

The motor has a good deal of right thrust in it, maybe 4 or 5 degree's. I have never had a delta with any thrust angle in it.
My Nitro Bobcat is straight in line, and so was my Enforcer.

Should I take out the thrust now or just change one or two things at a time??

Wingspam

On this delta, should I set the wing incidence at Zero or at plus 1 or 2 degree's?

Thanks