Well, it would probably work somehow (rather badly than well). I don't think it should change for anything other than that recommended by the manufacturer, because there are some requirements for it and no other oil has to meet that. In addition, it can directly damage the control components (for example, etch seals, etc.). The question is why I want to try it? After all, oil is not so expensive and in addition there is a small amount of it in the process. Servo drive oil is a so-called hydraulic oil, ie oil intended for the transmission of force and pressures, while motor oil is for lubrication under pressure and transmission oil is for lubrication without pressure. So in terms of purpose and "construction", everyone is completely different.