cactus hopper,
If I understand your post correctly, you mean the model is pointing in a constant direction but travelling around in a circle as viewed from above??
If so I had the same problem with a small electric Lama. The answer that I got from a helpful user of this site was to check for a bent flybar. The motion I refer to is called a bowl, so I'm told. My flybar was bent and removing it and straighten it solved the problem.
If I have not understood your post then don't read all of the above.