i buy any mitsi i can get cheap on ebay. mr-h, j2, or j2s . they are all good! the h series have to be hard wired as plugs are virtually impossible to find!
i started off with 2 mr-h series 2kw drives for £10 each which got me intrigued so i had to learn about them, and man there was a huge learning curve!
the hardest thing is making a pair as there are loads of drives and loads of motors coming up all the time. the mitsubishi drives are motor wattage specific and not forward compatible. so a j2 wont drive a mfs or kfs series motor but are backward compatible so the j2s series will happily drive a mf or kf motor etc. they use serial encoders which transmit model and motor info so a wrong combination just shows an error alarm.
the encoder passthrough is a great way to slave servos too without using further outputs from mach etc, with the j2s this can be done serially too!
the older motors have resolutions as low as 8192/rev the newer motors up to 15 bit. (130000 odd) either has plenty of resolution for mach/ galil mills etc
i probably have a collection of over 100 "pairs" here now ranging from 053 to 2kw sizes.
up to 750 watts can be run from single phase 230volts. higher than that your into 3 phase.
i got fed up losing steps on a mini boxford lathe so i fitted servos 053 with j2s drives (£100 per pair roughly) total accuracy now!
the 2kw drives i have will be going into my refit of a 3metre biesse router but im setting it all up using the old dc stuff with galil first so i can still use the old controller until its done! this old 1993 machine has 500ppr encoders and still gives pretty good accuracy. by the way 2kw is the output of the starter motor on my mercedes sprinter so you can imagine the torque these things produce!
the 400 watt size are great for a medium sized router , plasma etc. if work didnt keep getting in my way i would have my plasma table finished by now!