I don't know a damn thing about Haas, but I can give some insight on Fadals. Brought in a used one where I used to work, and now out on my own, my first "real" machine was a Fadal, a '93 4020, for good reason.

The shop I ran previously, we had Mazak's and that one Fadal. I loved the Mazaks, they were drop dead realiable and fast and accurate, but when they broke and it wasn't often, it was usually big dollars, $13k for a spindle.

The Fadal, it was a '97 4020, it had its problems, a few crashes from crappy operators blew a few driver boards over the years. Normal maintainance stuff like Bellevilles, had some wires in the flex going to the X and 4th axis, burnt up a few chiller pumps, thrust bearings. However over 4 years all the repairs on that one machine didn't add up to the cost of one Mazak spindle.

So when it came time to pony up for my own first real machine (an Acroloc isn't a real machine). Between me and my partner, it was going to be Fadal. First, the amount of real estate for the money, you can't beat it. I was looking at boxway machines, so thats good too. The control, I was looking for an 88HS, so '93 and up, is just stupid easy to use. Parts are cheap, with companies other than Fadal dealing in them, CNCpros, and UptimeCNC are two I've bought from recently. They are easy to work on.

When you get a used one, there are things I would go through and check and replace. No matter what, new Bellevilles and drawbar floater, run you about $75. Good tool retention is important and both used machines I've dealt with came with 16 and 22 of the 42 washers shattered, NOT good for tool retention.

Check the endplay on the ballscrews, the thrust bearings can go to hell quick, especially with the cooled ballscrews(un-plumb those, its just trouble waiting to happen). About $85 an axis for bearings. Check the motor to ballscrew couplers, they are only held on with a single 1/4-20 setscrew pushing down on a key. I pulled mine and added two 3/8-16 set screws while leaving the 1/4-20 to push down on the keyway, also ground flats on the end of the ballscrew and the motorshaft.

Take the time (box machine) to go through the manual and make all the proper Gib adjustments, its a pain in the ass, but worth it. I had to replace some of the gibs, they were the old style steel with turcite and they had become delaminated, the bronze ones are only $40 each, so not a big hit $$$ wise.

Check your oil lines, if anything looks suspect, change it, you can buy enough nylon line and fittings to do the whole machine for about $50. I've only replaced what was damaged. Also, oil injectors, there are about 20 of them on the machine and at $24 on sale a piece, that can get pricy. I pulled them all and threw them into an ultrasonic cleaner ($40 at Horrible Freight) used hydraulic oil as the cleaning fluid, and tested them by running each injector straight off the waylube pump. I had to buy 3 new ones.

So for around a $1000 and some TLC, its not that hard to end up with a machine that is going to perform almost as new. I didn't do all of this at once, and I should have, but I had chips to make. I'm back to near the factory backlash settings on a machine that can get its drivers license next year. Its paid for itself 7 times in 9 months, not bad.

Downsides of the machine, its not really fast, toolchanges are insanely slow, rapids kind of suck. I wouldn't use it to contour a mold at 500ipm. Upsides are that is cheap, easy to fix, fairly reliable, lots of support, quite rigid when taken care of (those damn bellevilles).

On the phase converters, they are a pain in the ass, they make noise, they aren't cheap, and they break. If you can get your hands on a single phase transformer, and don't see 3 phase coming your way anytime soon, go that route.

I actually like the Fadals so much, I've got another one coming next week.