I want to have a go at assembling my own (small) milling head from off-the-shelf parts. I am going to use this project mainly as a learning experience to get familiar with the process before attempting to build something with more expensive components. I will fill in some of the gaps as I go but I wanted to make sure I am buying the right parts. I know that some of you guys have done this before so I was hoping you could set me straight if I am missing something.
I plan to start with a cheap R8 spindle cartridge like this (as it's just for education):
https://littlemachineshop.com/produc...3751&category=
It is my understanding that when they call it a "cartridge" it means that it includes the spindle shaft, all the bearings and the housing / quill / flange. I.e. Everything except the motor and pulleys. Is this assumption correct?
The plan is to buy a pair of metal pulleys with a 1:1 ratio and driving the spindle via a rubber timing belt with a brushless DC spindle motor like this one:
https://www.automationtechnologiesin...or-and-driver/
I am aware that the spindle is rated for 1000w and 5000rpm while the motor is 1100w and 6000rpm max. My thought was that if I limited the motor to 5000rpm then it wouldn't exceed 1000w. Or, I'm sure I can find a cheap 1000w max motor on ebay.
To connect the motor / belt and spindle, I would buy or make a casting. Little machine shop sells some inexpensive cast iron ones that could probably be adapted (if they don't fit out the box).
Would this motor, cartridge and casting make up a complete milling head or am I missing some key components? (Aside from the drawbar and toolholder)?
For example, how does cooling work on these smaller milling heads? On high speed air cooled spindles, there would be a shaft fan or a separate electric fan but I can't see how cooling works on mini mill spindles. I know that some electric motors have built in fans but my understanding with spindles is that it is the bearings that need to be kept cool. Would I need to buy a separate electric cooling fan?
I looked through the write-ups for some other diy mill and CNC projects and I couldn't see any other components but I am having those "surely it can't be that easy" thoughts.