in the axieme insert with the sketch command of the convenient lines for the axes and references you need.
first insert relationships of axiality (with unblocked rotation) and flatness. if you need more active references from the context key "view parts of the component" and put plans, or sketches, or coordinate systems at will.
Usually for gears, to get drafts with the classic rules of the design, a solid is drawn up to the diameter of hazelnut, then the surfaces for the primitive diameter and for the external profile of the teeth are added.
if your pieces have teeth or tab locations, then you need a fasatura that will obviously depend on the gear reduction ratio (i).
so you can use the relationship of st6 "enlargement" or two angular relationships: if with "enlargement" (see guide, I never use it, by historicity) you have problems of initial fatigue then use two angular relationships (which exploit the reference plans).
how to control the value of the corners? go to tools / variables:
identify the angle of the wheel, rename it for example in "motor", idem for the angle of the wheel conducted: "condotta", then in the aconduct, put the formula you like the most: aconduced = 90° + lover * i
where "90°" is the initial beam angle, "i" the ratio: it can be a direct number or reference to a variable. to create a new variable you write in the last row of the variable table.