Posting this here as FYI for others that might be interested in doing something similar. I have a CAMaster Stinger II router originally equipped with a Milwaukee router, have had the CNC for over 2 years. Was starting to have some issues with the router so decided to put the money towards an upgrade to a 2.2KW air-cooled spindle. I ended up with a Chinese clone from HQD and it's working great. Gary Campbell of GCNC who posts here put together a complete package for me along with step by step instructions to make the conversion. I was impressed with the package and only had a couple of minor questions as I went through the install. If you're interested, you might send Gary a message- I have no financial interest to do this, just happy with how it turned out and until Gary changed my mind, thought this was something beyond my scope. I sent him a number of pictures of my CNC set up ahead of time and he used this to determine what needed to be done, gave me a few options on the hardware, etc. I stayed with manual control of the spindle speed using an extended keypad rather than switching to software control. In my case, both would have been around the same price but I like having the key pad at the spindle where I can see and listen to the changes.
This is the first spindle I've ever been around and boy is it quiet, will see how it holds up in the long term but a good start. I did have to change my KentCNC dust shoe and remount the laser. Turns out that 1/2 of the old aluminum router mount worked fine to hold the laser with one new hole for attachment. A few updates to a couple of the macros in WinCNC and I was back in business, have run several files and no issues to report. Here are a couple of pictures in case you're interested.