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Cleaning Dial Indicators
- Thread starter porthos
- Start date
- Joined
- Dec 18, 2019
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- 7,425
The two Mahr indicators on the left, how are they used? Can't quite tell from the picture. (The picture doesn't show the whole instrument.) Seems to have a lot of zeros! 0.00005"/div ! According to Mahr, the Millimess are dial comparators? Is this for go/no go measurement? Haven't seen a tool like this, so I am curious about what it is, and how it is used.I think I need some mineral spirits for a few of these .
- Joined
- Nov 26, 2017
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- 1,532
They are used in production to check parts against a standard, most often the standard is the first part or a reference part. You set the unit to zero with the standard and then you can measure all others to see if they fall within tolerances.
That type of gauge is used also used to test surface plates, mounted in a special fixture.
I got a sticky Japanese Peacock indicator for cheap. It's 0.001 x +/- 1mm, that's about 0.00004" resolution. I took apart what I could safely, then stopped before getting in too deep. Because it's "shockless" the stem is not directly linked to the sensitive movement. I started with naphtha because it cuts oil very well, unlike alcohols. As I understand it lighter fluid is just naphtha with nothing added. It has no lubrication in it but it tends to thin the old dried oil it does not remove and redistribute it. Naphtha also generally does not attack plastics. In this case I didn't get perfect results, so I followed that with automotive aerosol Mass Air Flow Cleaner. It's pure and also safe for plastics and electronics. That did it and now the indicator works perfectly again. In this case I did not add any lubrication.
I also use this technique for camera shutters all the time if I can't completely disassemble them. Just like a shutter, I had to let the indicator dry completely and exercise it before it worked without sticking. If you don't take the things completely apart and clean and dry the parts individually, the very close fitting parts take a long time to dry out. The still wet parts will sometimes fool you into thinking it's working because the trapped solvent acts as a lubricant. The next day it may be sticky again. If it is, just do it again. Good luck.
I also use this technique for camera shutters all the time if I can't completely disassemble them. Just like a shutter, I had to let the indicator dry completely and exercise it before it worked without sticking. If you don't take the things completely apart and clean and dry the parts individually, the very close fitting parts take a long time to dry out. The still wet parts will sometimes fool you into thinking it's working because the trapped solvent acts as a lubricant. The next day it may be sticky again. If it is, just do it again. Good luck.
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- Jan 31, 2016
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- 12,901
Sorry Wobbly , late to the game . These are known as Mahr snap mics . And yes , they are set with gage blocks and are .00005 incremental . They are milimess indicators . The indicators are removable and can be used for most jobs requiring precision .