drill first conundrum

[allnew]

Much is said about drilling first; then cutting the tracks. I am not sure how I can do this once the holes have been drilled.
The only way to do it, I guess, is to do the autolevelling with the engraving tool and set the autolevvelled code aside. Then drill without worrying too much about depth or machine z zero.
I'd appreciate it if there's a more rational method.
tony

[booski]

Tony,

In my personal experience, the routine that I tend to follow means that the board gets routed first.

So, it goes a little like this:

1. Design and create cam/gcode and process via autoleveller
2. Set up the machine, stick the board down with double sided tape and run the autolevelled code and route the circuit.
*3. Change tool for a drill and set the drill code so that the depth of the drill is slightly more than the board thickness to account for differences in height.
**4. Change the tool for a chip breaker and cut the board out.

*3a. If doing double sided, drill extra holes in the board through into the spoilboard, 1mm, 2 to 4 holes that are in the exact same location whether the board is mirrored or not
**4a. If doing double sided, flip the board over and apply more double sided tape. Insert 1mm dowel pins into spoil board where the mirrored holes are, remove tape backing and placed the board over the pins and press down to secure the board to the spoil board and locate
5. When board is secured, remove the dowel pins being sure not to disturb the board, run autoleveller on the opposite side code making the dimensions SLIGHTLY smaller so that they fit inside the cut board and run the opposite side code.

It is a little awkward doing double sided boards, but the method works quite nicely and a small wire stuck to the side of the board in between the probe points allow for continuity.