On a milling machine you want to set a zero margin. ( i hope this is correct english ) i mean by this that i want to set a zero point.
To setting my zero point i use a side-finder. In dutch : kant-zoeker
some people call it a “Zentrofix”.
It’s a very handy tool. Use a turning speed of 630 omw/min.
when you hit the product the zentrofix goes shifting.
Turn on your machine ( 630 turnings per minute and move the zentrofix careful to your product.
when the two pieces are exactly straight then you see nothing , but when you goes 0.002mm further then they are not anymore in a straight line like this picture.
The benefit if this tool is that your product not damage.
An other tool is a Turn Feeler ( i don’t know the exact word for it )
For the most of the actions i use the measurement tool.
This is a Dial test indicator
This will be often used on CNC Machines.
turn with your hand the Dial test indicator to the product and set the ax to zero.
Then hit the other side and split the distance in 2.
Then you have the exactly middle of your product.
To set the Z ax.
measure a piece of material. I used a parallel block.
DO NOT TURN ON YOUR MACHINE.
Lay the parallel block on your product and move the milling tool to your product. When you do this pull slowly to the parallel block and when it stuck that’s the Zero point of the Z ax.