Dial Indicator Fan Mount

Magnetic mount for a [dial indicator*](http://www.banggood.com/0-12_7mm0_5inch-0_01mm-Digital-Dial-Indicator-Electronic-Dial-Gauge-p-954736.html?p=EY011634303112016018), designed to screw in place of a 40mm fan (or over one). Makes it easier to level a build plate more accurately. The digital dial indicator in the picture is 57mm in diameter.

Uses short [M3 socket cap screws](https://www.trimcraftaviationrc.com/index.php?route=product/product&path=24_18_37&product_id=433) to attach to the f