[R_Newcomb]

Is there an option on Haas mills to make the table the Default z0 rather than the spindle face in home position?

That's how we have all of our Fanuc and Siemens based mills setup.

We have a VM6 and UMC750 with NGC, latest software as of last week.

[erikfriesen]

Do you mean as referenced against the ips tool setter or what?

[R_Newcomb]

For example. If I put a 4-inch block on the table, I want the Z offset to be 4 inches. Our acromatic2100 controller can do this with the spindle probe. The Haas machines comes up with a neg Z number.
The machines without probes, we touch all of the tools off of the table. I'd like to be able to do this on the Haas machines as well in case the probes fail or get broken.

[DMCain]

It is possible to set tool length without the probing system though it is NOT recommended.

Most common probe failure is dead battery. Change them every 6 months and write the date of the change on the battery. In the course if 5 years, we have
never had probe failure for anything except dead battery. We did have a probe crash into the table, but that was a bad cable on the Z-axis.

As for probe styli, keep 1 or 2 extra on hand in a relatively safe place as they are ceramic and can be broken by improper handling. Should only need to replace
stylus in the event of breakage or the ball getting chipped.

[erikfriesen]

It still seems a bit obscure what you mean by Z offset. Assuming you mean tool offset and not probed offset, the way I have done similar is to pick a work coordinate you don't use for anything else, say like G110 or G154.1 or something. Then set your Z probed work offset to the table. Then prior to setting off the table, do a G110/G154.1 in mdi, then hit tool offset measure to set your tools.

[Matt@RFR]

For example. If I put a 4-inch block on the table, I want the Z offset to be 4 inches. Our acromatic2100 controller can do this with the spindle probe. The Haas machines comes up with a neg Z number.
The machines without probes, we touch all of the tools off of the table. I'd like to be able to do this on the Haas machines as well in case the probes fail or get broken.

It doesn't really work that way. You have to use your probing OR not use it, you can't jump back and forth due to the negative-versus-positive tool length issue, as well as where the probe is calibrated (tool setting probe?). If you're worried about being down due to broken stylii, then buy extra just in case. If you're worried about actually crashing the probe, then you need to understand that probes are expensive, and replacements can be next-day-air'd in to get you back up and running. Probing is fantastic and I'll never have a machine without it, but they do come with some downsides that you just have to deal with.

[precisionmetal]

For example. If I put a 4-inch block on the table, I want the Z offset to be 4 inches. Our acromatic2100 controller can do this with the spindle probe. The Haas machines comes up with a neg Z number.
The machines without probes, we touch all of the tools off of the table. I'd like to be able to do this on the Haas machines as well in case the probes fail or get broken.

I do "somewhat" what you're saying on my Haas SMM, though ultimately Z0 gets offset to the origin of any particular part, no?

I set all my tool offsets to the table, and then just probe Z to whatever (top of part, step on vise jaw, reference on fixtures, etc.) and that becomes a positive value for Z in the work offset. Of course in order to do that, I had to probe the table once (which essentially gives me the "tool length" of the probe). Once I have that value, I always keep that negative number/value in the tool offset for the probe.

I don't know if this is any help in any way... just the method I use.

PM