Mitutoyo Digital Mic "Repair"

Bought a used Mitutoyo 1-2" digital micrometer, the IP65 type, model No.293-336. Cleaned it up yesterday (looks great now) but found that the thimble has just a bit of extra resistance past 1.6" or so. It was enough to stop the spindle and spin the friction sleeve. After a few back-and-forth runs it's gotten better, but I can still feel a little bit of a difference between the mic towards the anvil and towards its wider limits.

Here's the question: can I just unscrew the spindle/thimble from the body like a normal mechanical micrometer, or will this give me problems due to the electronics? I have the exploded diagram on Mitytoyo's website up right now, but it's not necessarily telling me a whole lot. I have the standards, so resetting the origin isn't an issue if that's all I have to do after checking the spindle threads.

105 views and no one's ever done this?

Yes, attempting to remove the spindle without the proper disassembly will mess the mic up.

As for the actual removal of the spindle, not been there, but had to do an adjustment on one. Worked step-by-step with a MIT tech on the phone. From what I recall, there are two set screws, one needs to be removed to access the second. The second is the one that tightens the reading sensor to the spindle. From looking at a Fowler digital mic that one of our machinists 'forced', this brand has a slotted spindle and by him forcing it out, he broke/lost the pin that slides through this slot.

I'm not saying it can't be done, just that this is not a "simple" fix. Sorry I can't assist in fixing your problem.

Not a big deal, thanks for the reply! After running the mic in and out a few more times the drag has decreased quite a bit - to the point that I'm getting correct readings on gage blocks. I believe that one of the rubber seals just stuck a bit after it'd been sitting so I think I'll just leave it for now, it seems to be "ain't broke."

drgn is correct. There's an encoder and sleeve that runs on the spindle; you need watchmakers screwdrivers and tweezers but its not a big deal.....but the spindle is not comng out or going back in without carefully placing these items which is done underneath the display panel. there are set screws in a V slot that does not (obviously) run the length of the spindle so these have to be removed

imo they are crappy mics (why I've had a few occasions to go in), just not as reliable as you'd hope from Mit.

Mcgyver said:

drgn is correct. There's an encoder and sleeve that runs on the spindle; you need watchmakers screwdrivers and tweezers but its not a big deal.....but the spindle is not comng out or going back in without carefully placing these items which is done underneath the display panel. there are set screws in a V slot that does not (obviously) run the length of the spindle so these have to be removed

imo they are crappy mics (why I've had a few occasions to go in), just not as reliable as you'd hope from Mit.

Click to expand...

I appreciate the insight as to disassembly, but really, whose mics would you recommend then? After seeing examples of constant use they seem to hold up far better than their Starrett counterparts, and they are more reliably repeatable than the Starrett mechanicals that I just sold with regards to measurements in tenths.

Atomkinder said:

I appreciate the insight as to disassembly, but really, whose mics would you recommend then? After seeing examples of constant use they seem to hold up far better than their Starrett counterparts, and they are more reliably repeatable than the Starrett mechanicals that I just sold with regards to measurements in tenths.

Click to expand...

for a digital not sure. I've had a few mitutoyos stop working, nothing obvious when taken apart, and i've got two that aren't relialbe - as in they don't hold position or will skip 10 thou if you spin the barrel too quickly to get for A to B. makes you lose confidence such that now i'm always zeroing or checking them. Some bright spot might say you should do that anyway lol, but not every use. With a manual you pick up and its where you left and it doesn't skip.

sorry I don't have a better idea for you, just kind of frustrated with them so mostly grab the manual mics now.....more of a pita as i have to grab the reading glasses to do a good job with them