Depth Gage Spindle moved when changing Contact Point

[WendyD]

I was changing the contact point on a new depth gage. I think the spindle may have rotated. The contact point is no longer flush to the base. It might be off by .02845". The depth gage (547-258S) is a Mitutoyo with a digimatic indicator (543-392BD). Can I adjust the spindle without damaging the indicator? I don't want to send it out for repair if I can help it. It's brand new.

 

[normzone]

I am not familiar with that particular tool, which makes me the ideal person to ask the obligatory dumb questions first without fear of humiliation.

"spindle may have rotated" - does the contact point thread onto the spindle? Is that the potential source of rotation you're referring to?

Has it seen any impact or other unlikely event that could change the spindle's opinion about where it should seat?

Have you removed the contact point, cleaned everything, and reinstalled it?

"might be off by .02845" - might be or is? How have you arrived at this number, in so many decimal places? Is the gage reading off this much or did you use other tools to decide this?

If the gage is reading off this much, can the gage be re-zeroed?

"The contact point is no longer flush to the base" - if you replace the previous contact point what changes to the device are evident?

 

[Jim Wynne]

I was changing the contact point on a new depth gage. I think the spindle may have rotated. The contact point is no longer flush to the base. It might be off by .02845". The depth gage (547-258S) is a Mitutoyo with a digimatic indicator (543-392BD). Can I adjust the spindle without damaging the indicator? I don't want to send it out for repair if I can help it. It's brand new.

See the attachment, which is a picture of your indicator. You are seeing a problem where the spindle or shaft meets the tip? Have you cross-threaded one of them? What happens when you remove the tip and put it back on, or put on a different tip?

 

[WendyD]

I am not familiar with that particular tool, which makes me the ideal person to ask the obligatory dumb questions first without fear of humiliation.

"spindle may have rotated" - does the contact point thread onto the spindle? Is that the potential source of rotation you're referring to?

Has it seen any impact or other unlikely event that could change the spindle's opinion about where it should seat?

Have you removed the contact point, cleaned everything, and reinstalled it?

"might be off by .02845" - might be or is? How have you arrived at this number, in so many decimal places? Is the gage reading off this much or did you use other tools to decide this?

If the gage is reading off this much, can the gage be re-zeroed?

"The contact point is no longer flush to the base" - if you replace the previous contact point what changes to the device are evident?

The contact point thread into the spindle. This is a new gage, never used. I was getting ready to calibrate it, and was changing the contact point. The contact point was on tight, and used pliers. I should have used pliers to hold the spindle while using another pair of pliers to loosen the contact point. I missed this detail in the directions. The spindle seemed to rotate but I wasn't sure if my eyes were playing tricks.

Before changing the contact point, I zeroed the indicator and was able to rest the base with indicator attached on a flat surface. The contact point was flush to the base when resting on a flat surface.

After changing the contact point, the contact point was no longer flush to the base. The indicator read .02845". I did not double check that number with another gage. I could tell something was not right since the contact point was no longer flush to the base when resting on a flat surface. I put the original contact point back on, but no luck. I can rezero the gage but it does not solve the problem.

 

[WendyD]

See the attachment, which is a picture of your indicator. You are seeing a problem where the spindle or shaft meets the tip? Have you cross-threaded one of them? What happens when you remove the tip and put it back on, or put on a different tip?

I'm not sure where the problem is. Everything seems tight when I attach the contact point and base. I put the original tip back on but I still had the problem.

 

[Jim Wynne]

I'm not sure where the problem is. Everything seems tight when I attach the contact point and base. I put the original tip back on but I still had the problem.

If everything seems tight, I don't understand the issue you're seeing. Is it that the tip isn't flush against the end of the shaft when it's put on? You say that it might be off by .02845". What are you measuring, and how are you measuring it?

 

[msec0990]

I found this post by accident, and it seems the OP never returned.

Having used a similar analog gage and not fully understanding the description of what happened, my thought is that the indicator may have moved in the depth base attachment as it is attached with a single set screw. I question whether this was "tight" if it was able to be moved that much, even with <shudder> pliers involved. That would most definitely have left a mark. I couldn't tell from the schematic I found online, but I would hope that the depth base has a split ring in it to avoid spindle damage. A damaged spindle usually means "damaged beyond repair" in my experience. This is something to consider in gage purchasing decisions.

We'll probably never know if this was the case or not, but hopefully someone will find this information useful.

Mark