Q: I have a Federal D8IS 1" dial indicator that I have been using on my lathe for many years to measure carriage travel. Lately it has been sticking, so I disassembled it, cleaned all internal components, freed the sticky plunger and am now ready for reassembly. I have two questions: 1) How many turns should I give the hairspring for preload at zero (plunger at rest)? 2) Should internal wear points be lubricated, shafts, gears, rack? If so what do you recommend?
- We use synthetic watch oil on the bearings and pinions but do not lubricate the rack (spindle) since this can actually cause stickiness in time. The hair spring has to be wound in such a way that it does not curl up when the spinldle is pushed completely in.
Q: I just bought a used Federal C81S dial indicator. When you manually push and release the stem it doesn't return to the same number. The rev counter is on 2 instead of zero. It seems pretty smooth. Can this be repaired?
- It could be repaired but Federal parts are so expensive that you will probably find it is not economical. Try this: remove the back cover and check to see that the return spring is still attached to its post. The spring could have been dislodged and that would account for the symptoms you describe.