Concentricity Gauge - Inconsistent Dial Gauge?

[cirles]

Hi Guys,

This is a brand new Mitutoyo 513-402-10E Test Indicator with the 21 Century Concentricity Gauge equipment. I tested it today to see if it was consistent in its readings & it does not appear to be so (it has not been dropped by me). Below is a link to a video I made

Notice I placed a black felt mark on the shoulder of the case to indicate when full rotation & therefore take reading from there. I have had this out by 0.001 returning to that mark. Anyone else with a similar setup experience this? Any machinist here who can comment on this? Possibly the 21 Century Gauge is the issue?

It may be best to download video to your computer because when I played it from the website it stopped and started, but obviously ok when played from computer. If any issues with playback please let me know here, I will monitor. Can anyone suggest a better anonymous file sharing service for this type of thing?

https://www55.zippyshare.com/v/1mxHtLB7/file.html

ALTERNATIVE LINK to above with less issues (this has been quite a process to resolve )

https://vimeo.com/370796545

[cirles]

Just to let everyone know, you will have to download this to your computer (154 MB) as I tried a couple more times, it is constant stop & start. Also suggest you zoom/enlarge image for the best view.

Again, can anyone point me to another anonymous file sharing service for this (so that it does not need to be downloaded by viewers).

[pomemax]

youtube
But i think you getting pressure on the guage from your hand try turning your friction wheel the other way

https://www.youtube.com/watch?v=Dc-9gbw8Iso

[marksman]

the file worked for me without downloading
l suspect the same as pomemax or another thing l could see is something like crud on the rollers that the case shoulder is sitting on

[cirles]

youtube
But i think you getting pressure on the guage from your hand try turning your friction wheel the other way

If you tap, or place your finger on the turning wheel, the dial does not register any movement (or extremely small movement). If I turn the wheel the other way it drags the case away from the stop guide rod & therefore gives incorrect readings as lever is then being placed on different areas of the case neck (instead of the 1 circumference area for measurement).

The turning wheel has to be placed at an angle on the case to constantly move it against the stop guide rod in order for it to work correctly.

[pomemax]

https://www.youtube.com/watch?v=Dc-9gbw8Iso
watch how little he moves the wheel for a full rotation
of course could be were missing the ovious the case is bent out of shape have you tried it on a few new bits of brass

[cirles]

https://www.youtube.com/watch?v=Dc-9gbw8Iso
watch how little he moves the wheel for a full rotation
of course could be were missing the ovious the case is bent out of shape have you tried it on a few new bits of brass

I think you will find I am moving it at the same distance as the video (maybe slight difference depending on the calibre), but I am moving it at a slower pace.

Regarding even if it was a bent case, would it not return to the same measurement for the same marked spot?

[marksman]

watching your vid circles and the other u-tube vid pomemax put up you can clearly see the rollers that support under the case near the shoulder on yours circles have tiny black bits on both the rollers that may be the cause of the inaccuracy of your concentricity gauge if they bump the case when turned it would be at different places on the case as the diameter of the rollers is different than the diameter of the case
if you have a bent case it will not change shape causing inconsistent readings of the case, it will be bent the same at the same point
clean the rollers on the gauge and then try again
sorry the photo is not very good but if you watch this area on your vid circles you will see what l am talking about, it may be wrong but worth a try

[Stix]

Hi Guys,

This is a brand new Mitutoyo 513-402-10E Test Indicator with the 21 Century Concentricity Gauge equipment. I tested it today to see if it was consistent in its readings & it does not appear to be so (it has not been dropped by me). Below is a link to a video I made

Notice I placed a black felt mark on the shoulder of the case to indicate when full rotation & therefore take reading from there. I have had this out by 0.001 returning to that mark. Anyone else with a similar setup experience this? Any machinist here who can comment on this? Possibly the 21 Century Gauge is the issue?

It may be best to download video to your computer because when I played it from the website it stopped and started, but obviously ok when played from computer. If any issues with playback please let me know here, I will monitor. Can anyone suggest a better anonymous file sharing service for this type of thing?

https://www55.zippyshare.com/v/1mxHtLB7/file.html

Gees mate...opening up that link creates all sorts of havock---random spam pop-up pages sounding warning alarms of identity theft, hacking & the like...
Is it just me...?
Or What sort of s**t is going on with that link...?

[cirles]

Hi Marksman, Thanks for pointing out the black marks. I had actually seen these but thought they were some type of stain because originally thought they were rust but had a look under magnification (10x) & as said looked like a stain). I will have another look at this as have another magnification device that goes to 50x. Will report back on this.

Another thing I have noticed is that 3 of the rollers run (relatively) freely, while 1 does less so. And that odd roller is one of those at the case shoulder end support. Hmmm.

I will see if I can clean the rollers of those black marks (rear ones have them also I think). What do you think I should clean this with, acetone?

[cirles]

Hi Stix,

Thanks for the feedback on the link. I had not experienced anything you indicated here, the only thing a friend said was that it required him to register before seeing, but again I never experienced that & simply uploaded the video to the link. I have also downloaded the video from that link to my computer & virus software picked up nothing. You have made me paranoid now so am going to run a back up anti virus Regardless that is a bit of a concern what you indicated. I use Firefox with & Add Block app, so not sure what is going on here.

Anyone else experiencing what 'Stix' has? Because if so then need to advise here to not follow the link & will have to try some other file sharing service.

[marksman]

even try isocol to clean it but having a closer look it does look like it may be an etch mark by your closeup photo, if it is and is the cause of the inconsistency in reading it should go back and be swapped out

[cirles]

even try isocol to clean it but having a closer look it does look like it may be an etch mark by your closeup photo, if it is and is the cause of the inconsistency in reading it should go back and be swapped out

Thanks for the input marksman, I am thinking the same thing.

My best course of action may be to approach 21 Century & see what they say. I originally thought the Mitutoyo gauge is the issue (still may be) but it is hard to eliminate which part is to blame. Will attempt the iso alcohol clean as have some & that should be fairly benign.

A friend can get a hold off another Test Indicator (so know accuracy) which I will do after trying something else to help diagnose the issue.

[cirles]

I ended up removing the marks with the iso pro alcohol, it looks like they were some type of marker pen(?) marks, they left a black stain on the cloth I used.

Followed a friends advice & decided to measure the back/base of the case area, to see if this made a difference there (different roller bearings area). While this did have less variation (up to 0.0005 max difference occasionally, usually 0.0003 or a bit less & could at times be either side of the zero indication). Not sure if this is acceptable variation, & if so this appears to show roller bearing influence as the shoulder roller bearings have the one that is not so free flowing so maybe causing the variation difference there.

[marksman]

I would say it isn't within the design specs, l dont own that concentricity gauge but know from the couple l do own you can have perfect concentricity,
zero runout
the gauge you have is a quality precision tool and IMHO is not up to the standard it should be, l believe something is not right
mitutoyo gauge's are quality but like everything can have defects so if you can like you said before try another to see if that is the problem
but if that does not work approach 21 century and see what they say is a good idea
good luck with it

[cirles]

Just an update on some further info. 21 Century has supplied, & perhaps something to take note off if considering this unit.

21 Century Shooting allowable tolerance is +/- 0.0005 for this gauge. So if you are trying to assess if you are within 0.002 concentricity (accepted benchmark) there is a potential 25% error reading with this concentricity gauge unit. Add to that the Mitutoyo Test Indicator has a 0.0002 accuracy repeatability error, that all adds up. We are measuring very small tolerance’s here. Hope I got my maths (25%) & theory correct here.

I will add that 21 Century is being very responsive in trying to resolve this issue. As indicated earlier, one of the roller bearing(s) (case shoulder support unit) is not so free flowing which may be contributing to the variation here.

marksman, what is the Concentricity Support unit & test indicator you use to take your measurements? I’m sure readers would be interested in that information