[blackout44]

So I'm looking for my first machine. My experience in CNC machining is limited, but I built my own plasma table so I'm already familiar with basic G code and machine commands. I'm also quite experienced in CAD/CAM as well, but just not the final step of running machines. I've got a background in mechanical engineering. CNC machining is mostly a hobby outlook for me right now, as I have a manufacturing business that pays my bills.

Anyways, I saw a 1988 4020 for sale on craigslist for $4k. Of course that price caught my eye (and made me ask questions).

Upon speaking to the owners, and inspecting it, this is what I found.

1. The oil pump is broken, and they have been "manually" pumping it. Red flag already for me.
2. They've had it for only a year, and know nothing about it. Their machinist who ran it quit (probably because of the machine IMO).
3. They had the hall effect sensor replaced recently. The technician who did the repair mentioned to them the 'issues' of the machine that he saw in passing (specifically the wear on the Z ways).
4. The X axis ways were destroyed. See pics.


Now, I am not familiar with replacement costs for the ways, but I do know a new oil pump itself is $1k. I am really questioning how many other unknown problems the machine has. It was under power and I was able to jog it through all axis, but did not have an indicator to check backlash on me (and the owner didn't have any indicators....)

Overall, it seems like this poor thing was really abused, and I'm not even sure I'd take it for free..... am I nuts for passing on it, or did I have a correct assessment?

[jgwentworth96]

I've seen clean machines sell for not much more than that. Good pass.

[Jim Dawson]

I'm afraid that machine is ready for a major overhaul (read: Expensive) or the scrap yard. Probably the latter. You did well to pass on it. Looks like it's had a hard life.