Z Axis Calibration Issue

[opsoff1]

Hoping there's a simple fix...
Just installed a Z axis scale to my mill. The last digit was constantly flickering up / down by .001". When I went to calibrate it - I got the same error no matter how many ties I retried. It tells me that "Excessive jitter detected difference of 7 encoder steps between readings. Each time I retried it - I got different values for the encoder steps - i.e. 7, 11, 5, 9, etc.
I've looked all the cables, shielding etc. The unit is new (i-Gaging E-Z View w/ micro USB connectors).
I read through all the trouble shooting write-ups on the Touch DRO site.
Thoughts?

 

[ChazzC]

Hoping there's a simple fix...
Just installed a Z axis scale to my mill. The last digit was constantly flickering up / down by .001". When I went to calibrate it - I got the same error no matter how many ties I retried. It tells me that "Excessive jitter detected difference of 7 encoder steps between readings. Each time I retried it - I got different values for the encoder steps - i.e. 7, 11, 5, 9, etc.
I've looked all the cables, shielding etc. The unit is new (i-Gaging E-Z View w/ micro USB connectors).
I read through all the trouble shooting write-ups on the Touch DRO site.
Thoughts?

EZ-view or EZ-View Plus? The Plus has a SS scale & I believe a more reliable read head, and is less prone to erratic readings due to electrical interference & “imperfect” mounting.

However, encoder steps in the range of 5 - 11 doesn’t sound right: mine are around 2,500 (10 um per encoder step): did you double-check your settings in TouchDRO?

 

[ycroosh]

Hoping there's a simple fix...
Just installed a Z axis scale to my mill. The last digit was constantly flickering up / down by .001". When I went to calibrate it - I got the same error no matter how many ties I retried. It tells me that "Excessive jitter detected difference of 7 encoder steps between readings. Each time I retried it - I got different values for the encoder steps - i.e. 7, 11, 5, 9, etc.
I've looked all the cables, shielding etc. The unit is new (i-Gaging E-Z View w/ micro USB connectors).
I read through all the trouble shooting write-ups on the Touch DRO site.
Thoughts?

iGaging scales have resolution of 9.someting um/2650 pulses per inch (as opposed to 2540), but that is besides the point. Flickering by one encoder count is very common and normal. Flickering by more than one encoder count is rare, not normal, and not fixable.

Long story short - this is most likely a compatibility issue; depends how new your scale is and how old your TouchDRO adapter is.
At some point within last two years, iGaging "nerfed" their scales for some reason. Recent-ish TouchDRO firmware mimics the timing of the original EZ-View scales, which sent 8 data streams with 16 data packets each (presumably to average the readings and get rid of outliers). In 2022 iGaging changed something, and the new scales stated glitching. In some cases slowing down the refresh rate works, but not in 100% of cases. The latest version of the ESP32 firmware has some smarts to slow down the refresh rate when it sees these glitches, so I can try re-flashing your adapter, but it's a crap shoot at this point.
When I tried talking to iGaging about, they told me that I'm their competitor, since they have their own "data solution" and they are adding "protections" to prevent me from "pirating" their scales.

 

[ChazzC]

When I tried talking to iGaging about, they told me that I'm their competitor, since they have their own "data solution" and they are adding "protections" to prevent me from "pirating" their scales.

My original installation with rev 1.1 firmware and pre-2021 iGaging Plus scales is doing fine, as is my Lathe installation with rev 1.6 firmware and iGaging Plus scales purchased (via Amazon from the iGaging Store [Anytime Tools]). However, wish I had a couple of pre-2022 scales just in case.

 

[opsoff1]

So...going back over how I had set this up, I "THINK" I may know where the root cause is at - and Yuriy's response above provides a lot of the info.
Hopefully someone can confirm my suspicions...

• Originally, I installed iGaging DRO's for the X & Y axis on the mill maybe 6 or 7 years ago. They were the DigiMag type. (mini USB)
• Fast forward to a year or so ago, and I "upgraded" to the EZ View style. (micro USB)
• When I bought the Touch DRO adapter the the EZ View type encoders plugged right in to the adapter. (micro USB)
• The Touch DRO was bought last fall (Oct 23ish)
• When I decided to add the Z axis read out, I bought a 6" iGaging EZ View set and discarded that scale.
• I took the 24" scale that had come with the X axis kit (EZ View) and cut it down to 16" for use on the Z axis.
• I had used the original Digimag scales with the new encoders since they were already on the machine.

What I "THINK" may have happened (referencing Yuriy's post) is I have an incompatible (new) scale on the Z axis now.

Solution??? If I can source an older scale - do you think that would work?
When I calibrated the X & Y - the encoder steps were different; one was 2659.00 and the other was 2663.33. I tried to manually input the encoder step in the Z axis - I just used an average between the two above @ 2661.00. Running the Z axis up and down it does return to zero, but flickers up / down by .001" and I still cannot calibrate.

Anyone know where I could source an older scale at least 16" long?

ETA: I found a 12" travel (16" long) Shahe set - Can I swap out the scale or even the scale & encoder and use this for my Z axis?

TIA

 

[opsoff1]

Solved..
While wait for a potential substitute, I decided to disassemble the Z scale & encoder from it's mounts on the column. While I had it on the bench, I compared the scale to the a few others I had (6" units). I noticed that there is a pattern imprinted/molded into the black center portion of the scale. When I looked at the 6" units I noted the orientation was 180 deg different. I figured that it can't hurt, so I slid the scale out of the encoder and flipped it 180 and slid it back in. I ran a test and it did not flicker and I was able to run the calibration option. I did not get any error messages re: the encoder steps. I carefully reinstalled it and run a full calibration on it. Everything worked perfectly. Not sure how or why this happened, but it seems like the orientation of how the scale in inserted into the encoder box is important. I have been checking it now for almost 2 days off and on - running the knee up / down, checking / comparing the dial readings to the DRO #'s - all good.
Who knew?! lol

 

[ycroosh]

Solved..
While wait for a potential substitute, I decided to disassemble the Z scale & encoder from it's mounts on the column. While I had it on the bench, I compared the scale to the a few others I had (6" units). I noticed that there is a pattern imprinted/molded into the black center portion of the scale. When I looked at the 6" units I noted the orientation was 180 deg different. I figured that it can't hurt, so I slid the scale out of the encoder and flipped it 180 and slid it back in. I ran a test and it did not flicker and I was able to run the calibration option. I did not get any error messages re: the encoder steps. I carefully reinstalled it and run a full calibration on it. Everything worked perfectly. Not sure how or why this happened, but it seems like the orientation of how the scale in inserted into the encoder box is important. I have been checking it now for almost 2 days off and on - running the knee up / down, checking / comparing the dial readings to the DRO #'s - all good.
Who knew?! lol

I've heard of this happening before. The thing that boggles my mind is that the original display somehow completely hides this issue. It has to be doing a LOT of very optimistic averaging to mask that amount of jitter.

 

[opsoff1]

Strange thing too - all the the jitter from the X & Y axis (4th digit /.000X) went away too. I had been using the T-DRO edit to only read to .001 but turned on the 4th digit to see what would happen on the Z axis once the scale was flipped. It was crazy stable, so I turned on the 4th digit for X & Y and it was all good.

 

[ycroosh]

And this is why I don't want to have anything to do with iGaging scales anymore

 

[opsoff1]

And this is why I don't want to have anything to do with iGaging scales anymore

I retrospect, I wish I had taken the plunge with glass scales years back. I cheaped out and went with igaging Digmags - they sufficed at the time. When I discovered T-DRO, I stayed with the igaging scales - It is running great now, but if anything goes wrong, I'll probably replace / upgrade to the T-DRO/glass scale config. I have gotten very comfortable with the T-DRO interface and options, totally love it. I've added a tach pick up and wired a jack for the touch edge finder. Using a tablet that I can quickly flip to an internet search / reference is a huge convenience.
Thanks for all you help and LOVE the product.