Hi everyone, i know this is incredibly stupid but i have a small 3 axis cnc benchtop mill which uses R8 collets. How am i supposed to properly set the bit height in the collet so that it is accurate with the material top? Up until now i have just been sliding a piece of printer paper between the end mill and material and that has been accurate enough. However, i am now wanting to create a part which is going to require a tool change midway through and i have no idea how to insert the new end mill so that it is at the proper height once the surface of the material has already been machined down? Also, what is the proper way of setting the material top so i can stop using a piece of paper? I understand i have no business running a mill with so little knowledge and when i have time i plan to enroll in a machining class at community college. Until then can anyone recommend any books that go over basic concepts such as this? Thanks!