I installed a new 80mm spindle this weekend and I will say that it works amazingly well.
I wanted to upgrade to something that could take a 1/2" bit as I use the CNC for flatten boards. I ran it today with some walnut and it worked beautifully. I was a little surprised and easy the upgrade was.
I did have a few issues, some of the bolts on the Z-axis were over torque and I snapped a bit trying to get them off. I was unable to get the broken bit out, so I was delayed waiting for a new Z-Axis.
The second issue I had was soldering the wire to the connector. My soldering skills are not great and I ended up having a friend come-over and do it. He did a great job and it came out perfectly.
The third issue was the settings on the VFD, from the factory the max RPM was set to a value about half the max settings. After updating, everything worked correctly.
I went with a 2.2kw air cooled as I did not want to add the hassle of water. I am happy with the sound and the cutting performance.
The only thing left is to find a better way of turning the VFD on and off, currenlty I have to unplug from the wall. I think I will look at a really or SSR and build a small box to control power.
If it is helpful to anyone else, here is a list of everything I purchased for the upgrade, and where I got it from.
Spindle Wrench - 21mm & 13mm