[rdsi]

My ETS has a carbide top. The issue is that it's not guaranteed to be parallel with the base like the one Tormach sells. On my unit the mfg has a couple of set screws mounted in the base so that it can be adjusted parallel to what ever surface it' mounted on - not very convenient.

As received without using the set screws to adjust parallelism there was about 0.004" variance across my carbide probing surface due to parallelism between it & the base. Rather than fuss with these set screws I made sure the ETS mounting surface was flat & smooth then mounted the ETS into my grinder & ground the carbide probing surface to be parallel with the base.

I just held the base on the grinder and did not constrain the probing surface while grinding. This worked fine & I was able to get the parallelism under 2 tenths.

You really need to use a ball probe to check the parallelism & either adjust it parallel using the set screws in the base or grind it parallel like I did. I'm thinking MFchief might be experiencing this issue whereas setting zero using the spindle is pressing the ETS across an wide area vs probing with a tool pressing the ETS at a single point. If your ETS probing surface is not parallel with the table, or whatever it's placed on, you will get a variance unless using a single point probe while probing the same point on the ETS.

MFcheif, it looks like in your pictures you have mounted the probe to a sub-plate of AL. This could be exacerbating your problem if this plate is not parallel. At the same time you could use this setup to get things parallel. Just probe the ETS with a ball and adjust the parallelism using the the set screws between the ETS base & your AL sub-plate? Apologies if this was your intentions in the first place.

[MFchief]

So, I think I'm pretty much at the end of this saga.

Did some checks with a 3.5" long 0.25" end mill and found a length variance when moving the tool in X or Y + - 0.25" from the center of the ETS of 0.0007" in X and 0.0011" in Y. That's total X and Y movement, not from the center, so actually not all that bad, since from center to edge was 0.0006" worst case.

But I went ahead and took the top off because of what RSDI said about reports of loose tops, I didn't find it to be loose on my unit, but was a little surprised about the inside appearance. The center was filled with some kind of soft black material that made me think of what we used to call potting compound.

When I made the sub base for the ETS, I did try to make the top and bottom as parallel as I could on the Tormach, but the question was still there, was it truly parallel? I decided to emulate RSDI and grind the top.. I first stoned the bottom of the base with a diamond stone, then I took it to the grinder. I had embedded three small RE magnets in the base, so setting it up on the grinder with the base installed insured the results would be parallel. I was a little surprise when the first pass on the grinder only touched about half of the top in Y. But I was encouraged because the difference matched the direction of the differences in length I was seeing in the test mentioned earlier. It didn't take long to finish off the top, which by the way, is carbide on my unit as well.

When back on the mill, I reran the test I started this post with, and my largest variance was around 2 tenth's, which I'm calling good.

Again, my thanks to everyone who helped with this issue!

Terry

[jttoner]

If it is the same as mine, the wires are red, orange, blue, & green. The red & orange wires make up a normally-open circuit, closed when the device is touched. The blue green wires are another NO circuit, closed only when the device is pushed down almost to its limit.

The red/orange pair is the one you want. The blue/green pair is meant for some sort of alarm or emergency-stop use.

Thanks, greatly appreciated.