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How to tighten loose test indicator probe

ballen

Diamond
Joined
Sep 25, 2011
Location
Garbsen, Germany
One of my favorite test indicators (Käfer, long probe, big dial, 0.01mm/division) was given to me a few years ago by a friend, who rescued it from the trash at work. It had been tossed because it failed calibration. He showed me the chart, where one point was a slightly out of the acceptable range. It's worked very well for me.

This evening I was using it and started getting really wacky non-repeating results. After five minutes of head-scratching I realised that the long probe had come partway unscrewed. It has a small flat for tightening, and I still have the little tool for that. Is it OK to just tighten it? Or do I need to support the bearing section at the same time? If so, how?
 
I've always just tightened mine with no ill effect. Just tighten it appropriately, not like a gorilla...

Just by the fact that you're asking first I think you'd have probably done that anyway. Some of the gorillas I've worked with in the past would probably have just cranked on it and snapped it off.
 
My indicator (Interapid) came with a little wrench to do just that. It was like a 3/8" disk with a slot in one edge to fit the probe. That seemed about right.
 
Tighten with caution because most contact points have a relief chamfer in the corner where the thread meets the contact point. It will break easily if tightened too hard.
 








 
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