Sporky McGuffin
Light entertainer
If you are looking at a three phase motor you can get a single to three phase invertor from ABB, Mitsi and a few others that will also deliver variable speed, if you look at the other option of digital phase convertors you lose the variable speed aspect.
So that adds another £300 (pretty much the cost of a decent router) on!
What would you consider low RPM ? You are right that they will lose torque as speed reduces, below about 6000 RPM my spindle wouldn't cut butter, warm butter at that lol
You can get the Chinese spindles from a UK source but guessing you might struggle with any sort of warranty, I have a 2.2KW water cooled spindle with ER20 Collet chuck so full range of collets from 1mm up to 12.7mm plus imperial at 1/8 3/16, 1/4, 3/8, & 1/2" . Think it was a half set of imperial I bought, wanted 1/8, 1/4 & 1/2 inch, then found I needed 3/8 for thread milling bit so it was cheaper to buy what I have rather than the 4 I needed lol, not sure if I will ever use the 3/16"
You would probably be OK with an air cooled spindle in the UK although I have heard that they are noisier than water cooled, not sure if that is true as I have also been told that is only true if the fan is mounted at the top of the spindle as most of the cheaper ones are.
At 5000 RPM I can surface timber with interlocked grain with the 52mm bit, taking about 0.75mm off at 1500mm/min. I don't care about the router noise because I've got a dust extractor running, and cutting timber is horribly noisy anyway
Any suggestion of suppliers to look at?