There are lots of ways to find the center of a hole. In a previous Fab Lab Video, we showed how to do this with an essential shop tool, the dial test indicator.
Mastering the dial test technique can take some practice. Although it can be very accurate, its not a particularly fast method.
On our Tormach PCNC mills and many other CNC mills, you can also use a touch probe, such as our passive probe or digitizing probe. These devices interface to the Tormach Machine Controller and can also be used for locating work offsets, tool setting, and much more. They are both versatile and fast. When correctly calibrated, they are very accurate as well.
A third way is to use a Coaxial Indicator. Coaxial Indicators are a very easy and accurate way to find bore or shaft centers. We now carry the Haimer Centro Coaxial indicator, which is a premium quality Coaxial Indicator, made in Germany. It has a large dial and a variety of interchangeable tips available that can be swapped out depending on the size of the bore or shaft that is being indicated. These work equally well on both CNC and manual machine tools. They are easy to use, even for inexperienced operators.
Here’s a short video on how to use the Haimer Centro.