Turntable Plus uses a little trick to avoid gimbal lock. It simulates a mouse drag on the canvas to turn the model. You need to set the axis of rotation in the Transform palette (usually Y). You also need to set the Preferences:Interface:Rotate Speed to a suitable value depending on the amount of your mouse drag. And the canvas zoom used to affect the result so that should be set to 'Actual'.
[IClick,1004,-4096,-4096,-4096+(shift),-4096]//'1004' is the numerical ID of the canvas
where 'shift' is the amount you want to drag the mouse. The negative values just keep the drag off the document.