I've been using a Bosch Colt as a spindle on my Taig (and my MaxNC) in order to get better production for making molds with small cutters in aluminum. The higher spindle feed does seem to make a difference and allow me to remove material at a much faster rate than with the stock Taig spindle.
However the Bosch Colts seem to have gone down hill in the last year with progressively less life in the bearings and often failing catastrophically (overheating and melting out the nylon nose bushing). We are talking much less with each router. I am sure I am pushing them harder than when I first started using them, but still.
I am looking for an alternative that can take hard continuos duty, and is still relatively light weight compared to the stock spindle and motor on the Taig. I just finished the mount for a PC 690LR on the Taig, and I'll be setting it up for a couple 8 hour cuts in aluminum shortly, but if it doesn't work any better I would be curious what solutions you guys have come up with?
I know. I know. Quit trying to get production level work out of a Taig, and buy a Haas LOL. Sorry can't afford it.
I considered one of the 1.5KW VFD drive imports, but I haven't found and answers regading continuous duty bearing life, spindle weight, availability of parts, etc.