ATC for High speed Spindle

I'm in the need for a high speed spindle (24k RPM) which can accommodate an ATC and use something like the Tormach ER20 holders.

Since these are readily available in the thousands of dollars for an import brand, I was wondering about making my own hollow spindle that can be used with an ATC setup and driving it with a side mounted 3hp water cooled Chinese spindle like the routers use. The spindle would have to be ground and balanced of course and some decent bearings but that seems doable for less than what it cost to buy one.

The only thing I see that may be an issue, is the side load on the spindle motor, but thinking about it, routers put a pretty good side load on the bearings already. at 24,000 RPM, the torque requirement for a belt is very low so a simple belt without too much tension should work pretty decent although I hadn't done the math yet.

The ATC itself and code is not problem as I have one I built and been using for sometime on my RF45, but now I want to add one to my CNC Router/Mill.
Yes, I mentioned mill for doing aluminum, 3D profiling at high speed.

Ideas and comments very welcome.

Richard

So is this different machine or for the RF45.

You will need to balance the TTS tool holders to spin that fast, which will require sending them someplace. Balancing them to 24K will be non-trival. You will also need to balance the whole spindle assembly once installed - and that takes some pretty serious equipment. Otherwise you will just toast bearings all the time running that fast with that much mass.

Our 16K RPM BT30 taper spindle at work was balanced at the nose and mid span with a sophisticated laser/vibration based balancing system once the machine was installed and level.

Hey Jid, good to hear from you!
It's for a new machine I'm building. I do have access to balancing machine so it shouldn't be a big issue.
I used to do this at my old place of employment and my brother in law bought the business out a few years ago. We balanced turbo chargers rated for 70K RPM and high speed turbines after we ceramic coated the shafts or did any machine work. Now, you're right, the tool holders would be a pain in the rump since they are so small and short. I may be biting off more than I can chew, but I'm known for venturing off into dark corners.

Richard

Haha - with the China spindles it won't be too expensive of a corner. If you can balance stuff then I'd say go for it for sure.