Kludge -
Oh boy, my first post on this forum - and I can contribute something. This semester, I'm an "assistant" at the local junior college machining class (all of the advanced classes were canceled) and in cleaning up the back room we found about a dozen bashed and broken dial indicators. I pulled them out of the trash and volunteered to try to fix them, as I did camera repair in a former life. Only one couldn't be brought back and it's now saved for parts.
If you can repair a watch, a dial indicator will be simple. The photo by rake60 answers most of the "what's in there" questions. Now the trick is how to get "in there".
Start with the back to get it looking like the photo, it's three or four screws and your inside.
Then remove the bezel and there are several ways they are held on: a- set screws around the outside; b- a wire spring that fits in a groove in the bezel and body (look for one hole where you can push the spring down and move the bezel out); c- a spring (or two) opposite a retainer tab that sits at about the 7 o'clock position in the photo (it's on the back of the face and near the wall of the case - loosen the screw and slide the tab away from the bezel); d- the two piece bezel with an interference fit (gently pry the outer ring and crystal away from the inner ring).
To remove the "works" there are usually three screws under the dial faceplate that will hold the guts to the frame. These also allow you to rotate the works and set the clearance between the rack (shaft) and pinion gear. On some indicators there will be two screws at (about the 1 and 7 o'clock positions) that hold the guts in - this will be obvious when you remove the back.
There is an extension spring from a pin on the rack/shaft to the bottom of the case. This pin rides in a guide plate and is usually threaded into the shaft. If you can remove the pin, it allows the shaft to be removed from the body and makes cleaning crud from the shaft a lot easier.
As for tension on the backlash hairspring - I ran the pinion gear until the thousandths and turns count hands are in sync. This puts enough tension on the gear train to take out backlash and make every thing "look right". On a 1 inch indicator there seems to always be about a half revolution of "extra" travel, so I set the thousandths hand at about the 9 o'clock position at rest.
You know about lubing gear trains, so I won't go there. The big problem I found on most of the indicators I looked at was too much oil. I guess it's the "if a little is good, too much must be better" philosophy.
Have fun and I hope this has been helpful.
Glenn
Oh boy, my first post on this forum - and I can contribute something. This semester, I'm an "assistant" at the local junior college machining class (all of the advanced classes were canceled) and in cleaning up the back room we found about a dozen bashed and broken dial indicators. I pulled them out of the trash and volunteered to try to fix them, as I did camera repair in a former life. Only one couldn't be brought back and it's now saved for parts.
If you can repair a watch, a dial indicator will be simple. The photo by rake60 answers most of the "what's in there" questions. Now the trick is how to get "in there".
Start with the back to get it looking like the photo, it's three or four screws and your inside.
Then remove the bezel and there are several ways they are held on: a- set screws around the outside; b- a wire spring that fits in a groove in the bezel and body (look for one hole where you can push the spring down and move the bezel out); c- a spring (or two) opposite a retainer tab that sits at about the 7 o'clock position in the photo (it's on the back of the face and near the wall of the case - loosen the screw and slide the tab away from the bezel); d- the two piece bezel with an interference fit (gently pry the outer ring and crystal away from the inner ring).
To remove the "works" there are usually three screws under the dial faceplate that will hold the guts to the frame. These also allow you to rotate the works and set the clearance between the rack (shaft) and pinion gear. On some indicators there will be two screws at (about the 1 and 7 o'clock positions) that hold the guts in - this will be obvious when you remove the back.
There is an extension spring from a pin on the rack/shaft to the bottom of the case. This pin rides in a guide plate and is usually threaded into the shaft. If you can remove the pin, it allows the shaft to be removed from the body and makes cleaning crud from the shaft a lot easier.
As for tension on the backlash hairspring - I ran the pinion gear until the thousandths and turns count hands are in sync. This puts enough tension on the gear train to take out backlash and make every thing "look right". On a 1 inch indicator there seems to always be about a half revolution of "extra" travel, so I set the thousandths hand at about the 9 o'clock position at rest.
You know about lubing gear trains, so I won't go there. The big problem I found on most of the indicators I looked at was too much oil. I guess it's the "if a little is good, too much must be better" philosophy.
Have fun and I hope this has been helpful.
Glenn
