From time to time it may become necessary to re-calibrate your boring bar micrometer.KW can not calibrate your micrometer here at our facility due to the fact that it must be calibrated to the boring bar that it is used in.
Please follow the the instructions carefully and your micrometer will be re-calibrated and accurate again within minutes.
1. Using a scrap block, center the boring bar to the cylinder to be bored, and tighten the base clamp screw.
2. Raise the boring bar up to allow the tool holder and bit to be installed into the boring head.
3 With the tool holder and bit pushed back into the boring head as far as it will go, tighten the gib set screw. Now lower the boring head until the the tool bit is just into the top of the bore.
4. Loosen the bib screw and allow the tool to carefully come out and contact the cylinerbore. Tighten the gib screw.
5. Raise the boring head to allow the boring bar mike to be inserted into the boring head. NOTE: Have the micrometer adjusted large enough so that the tool bit will not contact the face on insertion.
6. Slowly rotate the micrometer spindle untl the face of the mike JUST touches the tool bit. Now remove the micrometer and advance the reading by .010 to .015, then tighten the micrometer lock screw.
7. Insert the micromenter back into the boring head and loosen the gib set screw to allow the tool bit to contact the face.(Use caution so as no to have the tool bit scratch the face of the micrometer) Tighten the gib set screw.
8. Bore the cylinder.... now measure the actual finished size. DO NOT loosen or remove the boring bar. Take the measurement with the bar in place.
9. Place the stem of the boring bar micrometer into a vise with soft jaws so as not to damage the stem. Loosen the allen set screw found in the rear os the mike thimble in the knurled area.
10. Carefully rotate the thimble so that the mike now reads your bore size. Tighten the set screw.
11. Now loosen the micrometer lock screw and rotate the thimble either clockwise or counter clockwise, whichever direction is closer to thimble "0". Now re-tighten the micrometr lock screw at "0". If necessary, loosen the thimble set screw and slip the thimble up or down until the 0 is on the appropriate black line on the body of the micrometer then tighten the thimble set screw.
12. Loosen the micrometer lock screw and rotate the thimble to the reading of the bore size in your test cylinder. Now add .010 to the reading and rebore the cylinder. Measure the cylinder to verify size, fine tune your micrometer reading if necessary.