Zeroing from corner

[knowlzy0791]

I really ride the struggle bus when it comes to this issue. I cannot get it right the first time. If I run a ball nose on the edge of a square, it takes me a few tries to get it right.

Any tips out there on fixing this issue??

[JoeM]

If I'm understanding the problem - you have trouble telling when the ball-shaped toolbit is really sitting centered over the corner of the work. If so, this is what I do:

For anything except a v-bit, I use a stop-block that sits higher than the workpiece to set zero at the corner.

First I put the stop-block just touching the left edge of the work and run the toolbit left until it just touches the stop-block. I then zero the X-axis and set the X-offset to whatever the radius of the tool is.
Then I hold the stop-block against the bottom edge of the work and run the toolbit down until it just touches it, zero the Z-axis and set the Z-offset to whatever the radius of the tool is.

[FixitMike]

I use either a V bit in the chuck to zero (it has a sharp point), or a laser center finder http://www.lasercenteredgefinder.com/main.html . Once I have set the XY zero, I change to the bit I will use for cutting.

[Adrian]

I have a right angle piece with a copper cap in it that's wired to the same switch as my z-zero plate. Little bit of code in my controller software and perfect positioning over the corner of a board every time with no eyeballing.

[fatham]

If I'm understanding the problem - you have trouble telling when the ball-shaped toolbit is really sitting centered over the corner of the work. If so, this is what I do:

For anything except a v-bit, I use a stop-block that sits higher than the workpiece to set zero at the corner.

First I put the stop-block just touching the left edge of the work and run the toolbit left until it just touches the stop-block. I then zero the X-axis and set the X-offset to whatever the radius of the tool is.
Then I hold the stop-block against the bottom edge of the work and run the toolbit down until it just touches it, zero the Z-axis and set the Z-offset to whatever the radius of the tool is.

I would assume you mean Y AXIS Joe

[JoeM]

If I'm understanding the problem - you have trouble telling when the ball-shaped toolbit is really sitting centered over the corner of the work. If so, this is what I do:

For anything except a v-bit, I use a stop-block that sits higher than the workpiece to set zero at the corner.

First I put the stop-block just touching the left edge of the work and run the toolbit left until it just touches the stop-block. I then zero the X-axis and set the X-offset to whatever the radius of the tool is.
Then I hold the stop-block against the bottom edge of the work and run the toolbit down until it just touches it, zero the Z-axis and set the Z-offset to whatever the radius of the tool is.

I would assume you mean Y AXIS Joe

Yes! Y-Axis. Thanks for catching that.

[4DThinker]

If your control software allows it, bring the bit up to the side of the board slowly until just touching, then instead of entering 0 enter 1/2 the bit diameter. Use a negative value if to the left of an edge for X, positive if to the right of an edge. Use a negative value if in front of an edge for Y, and a positive if in back of the edge.

Alternatively you can set an offset from the corner of 1/2 the bit diameter when setting up your material for where X0,Y0 is. Then enter zero when the bit is flush to each edge.

4D