Rotary table and probe movement.

[[Lo...]]

Hello everyone,
I am using a rotary table and when it starts scanning a circle I notice the head is moving as well. I ran a base alignment using the same circle and it didn't do it then. But now even if I do a manual alignment the table rotates and the probe moves. I am trying to not have the probe move and just use the rotary table. What am I missing?
Thank you,
Lou

[[Ky...]]

Hello Lou,

If this is what I am thinking of, I saw this a couple weeks ago. Is the base alignment of the part in line with the rotary table axis, at least nominally? If so, double check the eccentricity in the rotary table menu (should pop up when you click on the rotary table button in the measurement tab). I would bet that it is significantly higher than it should be. To fix it, I would probably rerun your rotary table axis definition (or maybe make one off the part, depending on the situation).

Hope that helps.

[[Lo...]]

Thanks for the assistance Kyle. I reran the RT-axis and am still having the same issue. Attached is photo of the Rt pop up window. Also now it seems one for the circles I am measure with the RT. The RT now travels half way around the stops and alarms out.
Thank you for any assistance.

Capture1.GIF

[[Mi...]]

Have you tried lowering the scanning speed?

[[Ow...]]

I've never used an air=bearing rotary but, you might check to see if any of the default feature settings got skewed, like in the Measurement Plan Editor, see if the alignment rotates with rotary table is set to ON for all features except the features used to set up your symmetry, if using 3D lines created off 180° opposed circles .
Not sure what version is was but, in the features under special setting's, you also can choose to measure with or without the rotary and it seems like I've seen this activated in the feature and it didn't show it in the Measurement Plan Editor as off but was selected.

[[Ke...]]

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"if the alignment rotates with rotary table is set to ON"
I believe this was my problem, in the past.

[[Ky...]]

I'm sorry I haven't been able to look at the portal until now, but I was actually looking was this window, which you can get from resources>rotary table>RT travel commands if it doesn't show up for you when you open up the other rotary table menu:
.

That should show the eccentricity.

It is also possible that "Base Alignment is not rotating with rotary table" option is turned on in the feature as well, as Owen and Keith mentioned. I would think that it is a little unlikely since I think it would take a bit of strange button sequence to get that on by accident, but it's possible and worth checking.

(Note that in the last screenshot, the option should be set to "on" if you are not using that feature to define the RT axis).

[[Lo...]]

Hello all,
So it's been a minute since I have had this issue, and once again it has reared it's ugly head. I have ran several programs with the RT and haven't had an issue. Have also ran the current program twice with no issues and then all of a sudden the probe will start traveling around the part while the RT is moving at the same time. This is getting frustrating. I have attached a picture of my setup. What am I doing wrong? I appreciate any information.
Thank you,
Lou

Capture2.GIFCapture1.GIF

[[Da...]]

I'm not familiar with the rotary table, but I'm confused:
No valid RT axis is available.
Eccentric: 18.9017 inches

[[Ke...]]

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I'm not sure how much of a difference it makes, but in your RT set up screen, I always have "Homing Run" selected & set to "0".
Also, does your program re-measure the the RT Axis for every run? Or do you set up the RT Axis and then just run the main program? (I re-run the RT Axis every time...) again, not sure how much of a difference this makes, for your issue; but id does sound like there might be some sort of "Drift" taking place, over time.

[[Lo...]]

Thank you David. I have checked Homing Run and it's set to zero.
I always run from the features list, with the RT axis being first on the list.

So, this morning. I ran the RT Axis program as usual. I selected my program and did the manual alignment, the program ran fine. I saved it, reran but selected the program name and ran from the features list. And once again the probe started to trace the part while the table was rotating.
I tried doing another manual alignment again once it started to run the probe traced the part while the table rotated. There has got to be something I am missing or doing wrong. I just can't figure out what it is!!!
Thanks,
Lou

[[Ch...]]

Lou,

The only time I've seen the R/T rotate and the probe along with is :

1.) measure a thru hole for example that is off center of the part, and select measure with R/T, take a long time and looks funny, but works. Is the diameter you are measuring on center of R/T or is it a feature off-center of the part ?

2.) The only other time I think I've seen something like this is if the calibrated R/T 'eccentricity' is way too high as you shown earlier to be 18 or higher. That could definitely do it. I don't think Calypso was meant to function this way, it is just doing it's job to try to stay on the part.

Out of curiosity, if you take a dial indicator and put it on the OD of your rotary plate and rotate 360°, how much runout do you see ?

Are you measuring a feature on the part to determine R/T axis ? If so, have you verified you parts is not tilted to wobbling mechanically? Are you following proper procedure (measure at 0 and 180°<BA not rotating>) ? Do you know if part is machined well, or could possibly be eccentric itself ?

[[Lo...]]

Chris,
I am measuring a part with a vertical shaft using the 2 circles to create a 3D line and using that as my base alignment with a horizontal probe. 0 & 180 with the BA not rotating. Picture is attached.
I did put an indicator on the OD of the RT and it's .007 out of round.

Also I tried to qualify the RT axis again. And when it went to the 2nd position to probe completely missed the sphere. So I shut it down and tried again and it did the same thing. I got issues!
Thanks,
Lou

IMG_0304.JPGCapture3.GIF

[[Ch...]]

Lou,

Is the .007 in inch or metric ??

Im assuming inch. Also I dont think the OD is out of round, hopefully that is runout. If the OD is running out .007", I'd suggest getting that to < .0005", ideally less than <.0002", I would personally shoot for < .0001" but depends how well OD is machined sometime.

After that qualify your R/T axis again. (It may not hurt to re-do your 'position of RT' - if you know how to do that).
Are you applying proper filtering/outliers on your part?

If you are clamping in chuck jaws, have you confirmed that one jaws is not off a bit, causing your part to be off center?
good luck.

[[Lo...]]

Chris,
Yes .007 of an inch. As far as getting that to 0.0002-0.0001. How do I do that?
And I have done the RT-Position serval times. Thats the first thing I do when I qualify the RT.
I am applying filters and outliners, since they are circles I use undulations instead of wave length.
The chuck jaws are even, I tried another part and I am still getting the same thing.

Thanks,
Lou

[[Ch...]]

Lou,

Out of curiosity - if you put a dial indicator on the part - how much runout does it show ??

To correct the rotary table runout, is kind of machine shop 101, you should be able to ask any decent machinist for guidance.
Once you get that dialed in, and R/T reset and qualified - try putting an indicator on the part or a precision ground piece when it is clamped in the chuck to see how much that runs out.

Calypso can compensate for some runout - but only so much from my experience.

Once you correct R/T mechanically to < .0005" and part to less than .001" (those are rough numbers for me) I think we can help you further.

Good luck sir.

[[Re...]]

Good Morning,
if it's not a fixed rotary table you have to do the <rotary table position> under <Resources>
Measure your rotary table plate as a circle in a new measurement plan and define your position of the table first.
Then restart with manual alignment.
Maybe this will help.....

[[Lo...]]

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Thank you, this is a procedure I do every time I qualify the RT.

[[Lo...]]

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Thank you, I assumed there was an adjustment other than machining. And the part on a V-Block has 0.0004 (inches) runout. But I will see what it is mounted in the table. Thanks again!