I have a problem regarding z positioning of the tool after changing, for the next one (supose one make roughing and other semiroughing). How can I control this action in order to obtain the same position (on z axiz) of the tool tip for the next one I change? It is important when the engraving is made using 2 or more tools. Could you give me some tips? Till now I was using a single one tool to engrave an item for start to finish.:confused:

Hi Gravosfera
You could rezero the tool after each tool change zero being the top of your
work piece for each tool or make some little tool holders then you will be able to ajust each tool to the same length with a locking screw in the side of the holder grind a flat on the cutter for the screw to hold it

first i need to know what kind of holder you have?are you using a collet and just swapping tools?if you have actual holders you could pick them all up at the start and use tool offsets,tool 1 tool 2 and so on even though you manually change them its like having a tool changer so to speak.what soft ware you have,most have tool offsets for multiple tools,if you have no holders you can make up collars with set screws that lock on the tool for a stop agaisnt the collet when you change them,than use tool offsets for each tool,they work well collets usually pull a tool upward so you push the tool in with the stop agaisnt the collet and it pulls the tool up and tight,they repeat fairly well
steve

Collars with set screws work really well, tool changer or manual.

You can get these inexpensively (like US$ 4.00 per dozen) at model and hobby stores. They are used for, among other things, holding wheels onto model aircraft landing gear.

One of my CNC machines manufacturers sells them for several dollars each, I ordered some thinking they were special and found they were the exact same thing, just marked up a lot.