Calibrating HPC micrometer

[bobbybeatbilly]

Does anyone have experience calibrating the hoc micrometer. Hve one but it's no longer set to zero. I'm following the instructions but I'm running into problems with removing the outer sleeve the spindle seems to be attached the outer sleeve and doesn't look like the diagram. I can pot picturesif there is anyone that has one and knows how to calibrate it.

[bobbybeatbilly]

So for a few wonderful hours my micrometer was working beautifully and making imoressioning a breeze then somehow my hpc micrometer went .015" off zero. No problem I thought I'll jut calibrate it using the instructions. And now I'm running into all kinds of problems. Lots of love to anyone who has one and can help me figure out how to calibrate this thing.

Attached is a picture of wht I've dione so far and a link to the instructions. I removed the first part but the major problem comes when it asks me remove the "outer sleeve" In step 2.

As you can see in the picture, the spindle seems to be attached to the "outer sleeve" and I have no idea how to attach it so that I can place the anvil and spindle together and we the whole thing to zero.

Here is the link to the instructions http://www.hpcworld.com/Print/35T00_149_00.pdf

[mdc5150]

I could not help you with the micrometer, but a good $30 digital caliper will do the job. I bought mine at Lowes (Kobalt brand so it has a lifetime warranty) and I've never had a problem with it.

[bobbybeatbilly]

I wish those would work for me. I also bought calipers from lowes and Amazon and a few places but all of them give me different readings for the same depth. Sometimes ad much as .5 mm off. This one(when it's calibrated) gives the perfect reading time after time. For example a 5.26mm cut would sometimes show as 4.87 or 5.47 even after zeroing whereas the hpc micrometer is exactly on with very little effort. You just tighten till it stops.

[Josh66]

It looks very similar to a regular micrometer. Basically the only difference is the anvil.
Calibrating them is pretty straightforward (you shouldn't have to take it apart - in fact, it has to be assembled).
The small end of the spanner is for loosening the nut on the back (the small piece you have laying to the right), the large end is for making the adjustments. You can't see it in the photo, but somewhere near the zero (I mean, that 'band' of the cylinder, not necessarily right next to the zero) there will be another hole.

Do you have anything to calibrate it to? You have to have a block (in this case, a key) of a known dimension. You basically just 'measure' the block, then adjust the micrometer till the reading matches the dimensions of the block.

On a regular micrometer, you could just close it all the way and then zero it out. That might not be as accurate as using a block, but I think it would be within .0005". Anyway, I don't think you can do that with your's.


You need something to calibrate it to. You could measure a key with another micrometer, write that down, then adjust this one till it matches. Ideally you would calibrate this one immediately after measuring the key with the other micrometer to make sure that the temperature was the same and the key didn't become deformed or something between measurements.

No clue what the part number would be, but I'm sure there is a calibrating key you could buy that is certified to be a specific dimension at a specific temperature, and all that stuff.


edit
Changed pin to key. Also, it almost sounds like the directions are only telling you to take it apart so you can clean it prior to calibration. You should be able to make all of the adjustments just by loosening the nut on the back.
Also, you may be able to just close it all the way then zero it out... I was thinking that (closed all the way) should be negative on the scale, but the way they show it, it looks like zero IS closed all the way.

[bobbybeatbilly]

Thanks Josh for your help. You were pretty much right on for future locksmiths or hobbyists who may buy the hoc micrometer skm-1, after talking with hoc I came to find out the instructions included with the micrometer for calibration are obsolete. The new method is to loosen the screw on the bck nearest the anvil and simply pull the anvil down with e pliers until it touches the spindle while simaeltameously adjusting the thimble to zero.

[Josh66]

No problem!

I'm glad I wasn't just making things worse, lol! Though I have never used that particular micrometer, most micrometers are pretty similar in how you calibrate them. They're all basically the same design, with the ability to mount lots of different types of anvils to them.

It sounds like this one may not have that other hole I was talking about (what the large end of the spanner is for), or if it does it might be inoperative due to the nature of the anvil.

I wrote most of that before reading the instructions you posted, then thought - 'oh, crap - what if this one is somehow way different?'

The block I was talking about would be used by any lab you sent it to for calibration, but if you don't need the calibration to be 'certified', not using it isn't a big deal. We have them at work because all of our measuring instruments have to be calibrated and certified annually. I don't use them for my calipers and micrometers at home.