Micrometer Repair

[Downey Meyer]

Hi,

I am a high school science teacher and bought some relatively inexpensive micrometers to use in class. One of my students (while I was busy with another student) picked up one of the micrometers and backed the spindle all the way up to the stop. Now, I can't get it to move. Would anyone be able to suggest I fix?

I am ready to disassemble it, but didn't want to do more harm than good if there was another way to fix the problem. Thanks in advance for any help you can offer.

DM

 

[Downey Meyer]

Oops. Forgot the most important part. The micrometer is this one:

 

[JimDawson]

The only thing that comes to mind is to apply greater force than your student did but in the opposite direction. Short of that, some disassembly may be in your future.

 

[Tony Wells]

Very likely there is a transducer of some sort that may be keyed to the spindle, and having been backed out too far, the key/keyslot have become disengaged. I would hesitate to put much force on it. Short of finding a good parts breakdown online somewhere, careful dis-assembly will be required, I would say.

 

[jpfabricator]

Did the student learn s lesson?

Sent from somewhere in East Texas Jake Parker

 

[Riaan]

Stuff it in a sandwich baggie and put it in the freezer for a couple of hours. When its icy cold try and gently back it off. Alternatively leave it in the hot sun for a while. Remove the battery first.

The idea of course is to let differential expansion coefficents of the various materials used in its construction create a bit of tension relief.


Stupid question - have you disengaged the spindle lock?

 

[Downey Meyer]

Thanks for the quick responses. Yep, checked spindle lock. No, this particular student did not learn much from this experience. Will try freezing and warming. If those don't work, I guess that it is time for surgery.

 

[Riaan]

We have a saying here in South Africa, "Met geweld kan jy jou vinger in jou poephol afbreek.", or, "with sufficient violence you can snap off your finger in your arsehole".

This is by way of saying that Jim Dawson might have the right of it and that your level of violence might need to exceed that of the student.

Back in my day we would have exercised sufficent violence on the student's backside with a cane

 

[chip maker]

I guess if it were me I would just give Igaging a call or e mail them and ask what to do. If it is there unit I'm sure they have seen or done this to a caliper or two. I would surly try that before doing more harm to the gage. May be the easy way out and not cost you anything but time. !!!!

 

[chips&more]

Stuff it in a sandwich baggie and put it in the freezer for a couple of hours. When its icy cold try and gently back it off. Alternatively leave it in the hot sun for a while. Remove the battery first.

The idea of course is to let differential expansion coefficents of the various materials used in its construction create a bit of tension relief.


Stupid question - have you disengaged the spindle lock?

That could be a great trick/technique on something else. But I’m not too sure about the LCD display liking the freezing temperature. You could have another problem to deal with if that trick was used on the mike.