Laser alignment tool

[ricks]

David,
I zero my bot very much the way you have suggested. I use a copper pc board with a wire soldered to it and split with a banana plug that goes to the control box. (The wire also gets plugged into stops at x&y zero points to zero the overall machine.) But I use it mostly to zero the xy&z of jigs on the table that I can place anywhere. I have a wooden fence at the x axis and use plywood spacers to make sure the jig is parallel to it. I lay the pc board against the jig and have the router spindle hit it. (I'm using the "Eliminator" chuck which is round.) I rewrote the zzero program to work in the x&y direction.
I also thought about use copper tape on the corner of jigs but I haven't gotten around to that yet.
I also make guitars and furniture so there are lots of different jigs.

Rick Samish

[beacon14]

I also do the same thing. My z-zero plate is a piece of 1/8" x 3/4" aluminum bar stock, and I can hold it against a fence, using a modified version of the z-zero routine to create an x-zero or y-zero routine. I edit the value in the program depending on the diameter of the bit , and allow for the 1/8" thickness of the aluminum. (I use mostly spiral bits, so there is always part of the bit at it's outer diameter to make contact.)
I use this process whenever I am placing parts against a fence.
For general re-zeroing of my x & y axis, I have simple homemade contact switches made of a carriage bolt, spring, and double-nut. When the x or y carriage contacts the carriage bolt head, it does the same thing as when using the z-zero plate. I have a routine that starts near the home (0,0) position, zero's both axes, then returns to home. I do that before running any kind of program or if I'm in any doubt as to positioning accuracy. My homemade switches (which cost about a buck apiece) have proven to be very reliable and accurate.