Has anyone used a 6040 cnc machine from ebay?
I've had a 6090 4 axis CNCEST for about a year. I went with the 6090 because I wanted to do both inlays and tapers with it.
They seem to be hit and miss as far as QC goes and how much work it takes to get them running well. Electronics are pretty much crap but some have got them to work ok. I didn't have much luck and pretty much completely rebuilt the control box but it was well worth it.
Mechanically mine is pretty solid and accurate so I got lucky there. The only issue I have left to address is to replace the extruded aluminum table. It flexes way too much in the center due to being only supported at the ends (downfall of all gantry machines) and being over 41" between ends. But I ordered a solid aluminum plate a couple weeks ago and it's supposed to be delivered on Wednesday so hopefully I'll be able to swap it out next weekend. A 6040 may not be as bad in this regard since it only spans about 28".
Be prepared to spend some time getting it up and running well. Mine came with no support, documentation, nor software. I was pretty much on my own to track down drivers, control software, and settings for the VFD. I still don't have a manual for the VFD and I don't think one exists but thankfully a few guys over at the CNCZone forum figured it out and were kind enough to share.
If you decide to go that route I'd be happy to share what I know, just be aware it's not going to be a turnkey machine.
If I had it all to do over again I'd probably just try to find a decent frame and do the electronics myself, either that or build one completely from scratch, I'd probably be into it for a little less cash. But all in all, for the price they are not a bad deal. You can't touch a turnkey professional machine for less than three times the price.
I believe JC has the 6040 version of the same machine, seems to be working well for him, maybe he'll chime in.
Hope this helps.