I have just test flown an Arizona Models 1/5 DR1 and have found that the plane is very pitch sensitive. I am unable to trim the plane for hands-off level flight. If I move the elevator trim on the transmitter just ever so slightly, the plane will either climb or dive depending the direction of the trim change. In flight, I have to hold up elevator constantly in order to keep the plane from diving, with the elevator in neutral position. The CG is per the plans and I have added about 1 degree of down thrust on the engine. Any suggestions. Thanks

You might move the c.g. forward a bit, AND cut down on the elevator travel.
Dr-1s are poor fliers, and worse landers!
If mind didn't turn over on any landing I felt lucky!

You are right - the DR1 is notorious for difficult take-offs and landings, but I have to tell you that this one does not exhibit those bad traits so far. Take-offs are very easy and my landings so far have been uneventful. If I could just get it trimmed in the air, I would be very happy. Thanks for your suggestion.

It sure sounds like all the symptoms of the classic rearwards CG. But you might check for free play or binding that leads to lost movement in the elevator. I had a glider with a T tail driven by an S bent cable that had some lost movement due to play and stiction and it was a horrible model to find the neutral trim on. I learned to always enter the slow cruise from up elevator and the high speed mode from down elevator. The difference in hte return to the two neutral positions let me do this. Took some head scratching to find it though.