Was about to get a toy- then I did some research...

[NeoMorph]

For info, I currently run a 6.8 KW HSD Spindle on my Concrete mill. If you look up my build thread (search for Thor), you will find it. I started with a 4KW Chinese spindle which worked OK. Low / no torque and ER collets, found a 2nd hand HSD spindle and not looked back.

The problem with hobby CNC machines using full sized spindles is weight. For example the reason most router based CNCs use router is because of weight either bogging the gantry down or causing the Z-axis to fall (like the Shapeoko, Ox etc). I think the Shapeoko actually used a SPRING at one time to help keep the router from dropping and not being able to get back up again. So a proper spindle is out of the question.

New builders also don’t take into account the weight of water in water cooled machines which is why it’s better to use an air cooled one on a smaller hobby machine. Plus water is another thing I would want to keep away from wood. I got some lubricant on my waste board the one time and it had to be replaced because it swelled up over night.

I think everyone I know of (bar one who went water cooled and had to go double belt and larger stepper motors before it would stop bogging down) has gone the air cooled spindle route. But if I could afford all metal underside and stronger steppers or drives there would be no question. In that case it would be water cooled all the way.

At the end of the day it all comes down to cost.