Stu Miller
Hot Rolled
- Joined
- Apr 8, 2002
- Location
- Covington, Wa
Here is a tool I built to center things in my mill. As all of you who have tried to center stuff with a dial test indicator, the danged thing is backwards part of the time and it is easy to lose track of which way the needle is moving if you use a mirror. This device holds the test indicator horizontal so it is visible and allows fine adjustment. It is based on one described in Machinist's Workshop Magazine by Glenn L. Wilson, but significantly modified by me. My mods include the dovetail slide and the fine adjustment.
The above pic shows it in use centering a piece in a chuck on my rotary table. Below is the right hand side showing the tool up close. The head fits in a half inch collet and has a female dovetail with gib to lock the sliding male dovetail in place. You can see that the dial test indicator is held by a small block attached to the sliding dovetail with a thin piece of steel which serves as a spring hinge. Major adjustment is by the sliding dovetail. Fine adjustment is by the large adjustment wheel on the block that holds the indicator. It has a cam surface which rubs against the end of the dovetail piece and slightly bends the spring hinge for fine adjustment.
The pic below shows the other side of the device with the dovetail clamp to hold the test indicator.
Yes, I know I could just go buy a co-ax indicator, but this was free, fun, and educational. I learned to measure dovetails in the process, as well as threads by the three wire method, and the design and construction phases were both enjoyable. Retirement sure is nice!
Stu Miller
The above pic shows it in use centering a piece in a chuck on my rotary table. Below is the right hand side showing the tool up close. The head fits in a half inch collet and has a female dovetail with gib to lock the sliding male dovetail in place. You can see that the dial test indicator is held by a small block attached to the sliding dovetail with a thin piece of steel which serves as a spring hinge. Major adjustment is by the sliding dovetail. Fine adjustment is by the large adjustment wheel on the block that holds the indicator. It has a cam surface which rubs against the end of the dovetail piece and slightly bends the spring hinge for fine adjustment.
The pic below shows the other side of the device with the dovetail clamp to hold the test indicator.
Yes, I know I could just go buy a co-ax indicator, but this was free, fun, and educational. I learned to measure dovetails in the process, as well as threads by the three wire method, and the design and construction phases were both enjoyable. Retirement sure is nice!
Stu Miller