Building a Mini Spindle for the Shiz


I'm about to start doing a lot of CNC milling in my garage and that big 2.5kw spindle is making a lot of heat and noise when I run it at 3800 RPM. The 5HP Rotary phase converter is also contributing to the heat.

Most of the work is going to be pushing a .125" endmill through .25" plate, so I dont' need that much power for this work.

The idea is to build a new mini spindle that will clamp to the quill on the Shiz and allow me to run a 1/4hp 10,000 rpm motor which will generate a lot less heat and should be a bit quieter.

So, how does one make a new spindle? Start with a 1.75" piece of aluminum square stock. Cut it to 5" length then fly cut the ends to a perfect right angle.


Next, bore out the through hole and bearing pockets. Mill the pockets a few thou smaller so the housing can be heated to accept the new bearings.


I didn't have a long enough endmill to get through the 5" piece, so I'll have to finish that up on the drill press.

I picked up 5 of those ER collet chucks off Ebay for a good price. They are import, so we'll have to see what the runout is going to be once it's all assembled.


Still have to bore the spindle mounting holes in the housing, then it's off to debur and anodizing.