Hi.
ChExcelApp:Charts("Chart1"):Axes(2):MajorUnit = 100.
ChExcelApp:Charts("Chart1").Axes(2):MinimumScale = 10.
And more...
..... MaximumScale = 120.
..... MinorUnit = 20.
..... MinimumScaleIsAuto = True.
..... MaximumScale = 5.55.
..... MinorUnitIsAuto = True.
..... MajorUnitIsAuto = True.
..... Crosses = -4105. /* xlAutomatic */