When I zero xy z to start job then change to another bit say a bowl or v carve bit do I reset
xy z as my bit had been changed and I’m sure not the same height as previous one
I read those type of bits do not work due to size
and shape so when I put them in to carve
do I just load file and go. Or reset
I would say you should change your XYZ accordingly to the actual bit you are changing to. Do you have the auto touch probe, it works absolutely amazing.
I am assuming we are talking about a job broken into multiple files, one for each tool. For the first tool and file you set XYZ zero however you do it, be it touch block, eye, paper method. On subsequent tools and files as long as they all start from the same corner or center of the project you only need to reset the Z zero. So either paper or Z only probe.
@BKwoodcrafts As @_Michael said, you do not change/reset XY0. You only reset Z0 to take into account the change in bit length. @GettingStarted is mistaken.
I guess I was wrong.
@GettingStarted I meant no offence, Robert. I just wanted to ensure that @BKwoodcrafts had good info.
For any multi-bit/multi-toolpath project, you set XY0 once. Since the touch plate sets that spot with reference to the centre of the bit you use, any bit change will still have the centre of the bit at the same location. That way, you can be sure that all your tool paths will line up. That is why it is critical that, when using the touchplate, you enter the bit diameter of the bit you are using.
No offense taken Grant, I appreciate being schooled so to speak as I learned something new.
Ran another successful project thanks to the excellent explanation from grant now I have another purchased a file it was done with v carve pro. I can’t do it because of the size I have desktop unless I use tiling can I do that with a purchased file and how do I do it
@BKwoodcrafts I didn’t know that this was the same “Bobby”. 
It’s more than likely that you can tile the file.
-remember I’m computer illiterate! Will try to send file it was done on vectric v carve pro do I have option of making it smaller as it is multiple items of different design on one long board was thinking just delete 1 whole design that gets me to under 24"
@BKwoodcrafts I would need to see it, Bobby. It is likely that you can scale it down, but it depends on the design. Tiling it will work well, probably. See your email.