A very useful aspect to this simple spindle-holder project is it's consideration of cutting aluminium  on a home-built machine.  Along with project details, the originator provides the part diagram as a vector and makes the cutting GCode available for download.  Much of the information discussed can be applied to other projects using aluminium.

The cutting was performed in very shallow steps of 0.30 MM a step with a feedrate of 50MM per minute. This will be quite slow but was based on the use of a relatively low-power  spindle.  It may be possible to adjust these parameters for a faster cut depending on the hardware in use.  Click on the image to access the project details.