I just spent the last 30-minutes composing a post about this, but the Internet ate it. You can trust that it was witty and humorous, yet informative. I may have likened knifemaking to
Russian nesting dolls. It made sense at the time.
Anyway, long-story-short, I’ve been doing some work to improve the accuracy of my milling machine.
A month or so back, I bought an
Indicol-style indicator holder from Grizzly for $11. When I got home, I found that it did not fit my machine. Bummer. Apparently most of these are designed to fit the common 1-7/8” spindles of Bridgeport-style machines, and are not big enough to clamp to the 2.29” quill of my Grizzly G0463 (Sieg X3 variant).
Rather than give up, I decided to attempt to build a new clamping frame for the holder. The photo below shows some of the steps.
At upper left, you can see the holder as it came from Grizzly. The black clamp body is way too small to fit my machine.
To build a new body, I first disassembled the holder, scanned the original, then imported the image into AutoCAD at 1:1 scale. I then traced the scanned image, and scaled it as required to fit the quill of my machine. I had to do some tweaking of the mounting-hole layout so the original hardware would still fit and would continue to be centered on the spindle.
At lower left, you can see the ½” aluminum plate that I used for the new clamping body, as well as the scaled CAD design.
Finally, at lower right, you can see the holder reassembled with the new clamping body. I’m pretty stoked with how this turned out.
In the six years since buying this little mill, I had never once taken the time to check it for squareness. One of the main reasons for the new indicator holder was to aid in the measuring and tramming process.
So, last night I did some tramming. I primarily followed the process outlined on Yuriy Krushelnytskiy’s webpage
HERE. I can’t say that I got everything dead-nuts… but it is definitely MUCH improved.
Some things I learned:
- My Fowler machinist square is not, in fact, square. It's not even completely FLAT along it's length. I'm glad that Yuriy recommended testing in both directions.
- Tramming is a bit like voodoo magic.
- Better is good. Perfect is impossible.
Erin