RE: U-CAN-DO 3D .60, What engine?
If you dont get anywhere with the ST G90 then compare the weight between OS 1.20 AX & ST 90,bet the difference is not that much. If not, consider the 1.20 AX as a great 3-D engine for the Do and other planes as well. I have one in an X100 @ 8.75# and its amazing.