Contact points are held securely in place with a set screw which is inserted from the back end. Swivel the point to the side and you'll see it. A very small screwdriver is needed to loosen this set screw by a half turn. This allows you to unscrew the contact point. Many new Girod contact points have a strange burr above the thread. You may find that you can't insert the new point without stoning off this burr. When the new point is screwed in, you'll want to tighten the set screw again. Notice that, if the set screw is too far out, you may not be able to swivel the point back into position. This same set screw is used to shorten or lengthen the contact point so that the indicator calibrates correctly. It's quite a nuissance. You'll have to calibrate the indicator and if the readings are over by one graduation or more, you'll want to lengthen the point. Do this by screwing it out, by 1/2 turn at a time and then retightening the set screw. Calibrate again, and again, and again until you get it right. Why did the manufacturer torment us with this "feature"? If the contact point is used at an angle you will have to make mathematical adjustments for the cosine error. However, on this kind of indicator you can permanently adjust the length of the point so that readings at a particular angle will always be correct. If you can master this, you deserve a gold star. |