How do People Find Used CNC Machines That Are Worth Buying?

What I am seeing is the planned obsolescence of machines is usually a shorter amount of time than it takes to really wear them out. Couple that with machine shops being an extremely competitive business and the machine is actually a small expense in comparison to the people running them. If the machinist is making $50k a year a $20,000 machine that has a 10% improvement in production will likely pay for itself in 4 years. 1.5 years if it is running 3 shifts a day. If your shop isn't making that investment, it isn't getting the contracts with the big numbers after the $ sign on the checks.

I actually see a lot of CNC machines that have life left in them for the hobbyist that are just aren't profitable for a machine shop any more. But they are a hard sell to the hobbyist because of the size.
 
Sometimes they just show up on your doorstep :) https://www.hobby-machinist.com/threads/my-huge-new-to-me-cnc-mill.80578/#post-693874 But most times you have to look around a bit.

As others have said finding an older VMC with bad controls or just obsolete controls is really pretty easy. Nobody wants them, and you can pick them up for scrap price. The problem is finding one that has a small enough spindle motor that you can actually run it in a home shop with the normally limited power. You need to decide just what size machine you want, they come in all sizes from tiny to it ain't gonna fit in the space you have for it. :grin: Seriously, the question is what do you want to do with it and what work envelope do you need to accomplish your planned tasks. No matter what you get, for at least that one job that's going to come up it will be at least 1 inch too small. ;)

If I had only one mill I would want one that is both manual and CNC capable. There were a number of 10x50 BP clone type knee mills that were imported in the mid 80's to mid 90's and fitted with Anilam CNC controls as well as retaining the manual capability. The mills were built by Topwell, a Taiwan builder of quality machine tools, and may be branded Eagle, or a couple of others I forget. I think there might have been a couple of US companies doing this. I managed to snag one of these for $1000. Mechanically near new, but a tired controller, but even at that I managed to get a year or two out of the old controller.

Here is a good starting point. Search Tempest. Searches all of Craigslist within a radius that you set. https://www.searchtempest.com/

To try to determine what condition the machine is in, look at the general condition of both the shop and the machine. A machine in a well kept shop is probably better cared for than one in a disaster area. Talk to the owner, just ask what condition the machine is in, most people are honest. Ask about known problems, and get some history. Hear it run if possible. Look at the ways, if moderate to no wear, then take it home with you. :) One of the things that I do is to look at the oiler, if it's empty then I'm going to have a harder look at things, if it's half full I'm pretty happy. Look for oil on the ways and ball screws. A couple thousandths backlash in a ball screw would not worry me as long as everything turns smooth.

On VMCs you normally can't see the ball screws or ways, they are covered. This is where you reach under covers if possible and check for lubrication on the ways and ball screws. Don't expect too much, but you should have some oil or grease on a fingertip. The good news is that the old machines are pretty stout and don't wear much as long as they are lubricated. They were designed to be rode hard.

If you can run the machine then listen for unusual noises, but CNC machines are not normally quiet. Ball screws make noise at higher speeds, as can the spindles. It's pretty hard to tell where the line is between good and bad. Crunchy sounds are bad.
 
This site can be handy. https://www.bidspotter.com/en-us/auction-catalogues
Never seems to be an auction close to me, but you might have more luck.
I found one of mine (lathe) on craigslist local to me (100 mi.)
Found the other on search tempest. It was in Portland and cost almost as much to ship as it did to buy.
 
It's not really possible for me to examine a CNC machine and evaluate it myself, which is why I posted the thread. If I could do all those things, I'd already be an expert, and I wouldn't need help.

There really is no solution, except for paying hundreds or thousands to have other people help me. I can't go to local shops and ask busy strangers to ride around with me and look at machines in exchange for beer. They'd think I was a stalker.

It's encouraging to hear that shops get rid of machines that aren't worn out, but all I've ever seen in Florida were old machines, like pre-2000. Imagine how many hours a production machine racks up in 20-30 years.
 
One avenue that hasn't been mentioned here is a used machinery dealer. There are a number of them within 100 miles of you. We actually bought our Haas from a Florida dealer near you. The machine tool dealers are experts and have a reputation to protect. I have never run into one that didn't give an honest evaluation of a machine. And salesmen like to talk to anyone who walks in the door, but they are pretty good at weeding out a serious buyer vs. a tire kicker. Also they understand that they have to compete with Craigslist and Ebay on pricing. They normally buy machines at near scrap prices, sometimes make needed repairs, and resell them at a reasonable markup.

You would not get a warranty on a 30 year old machine, but you would have a pretty good idea of what you are buying. And frankly I would not have a problem buying a 30 year old machine, they are built heavier than the newer ones in the same size range. My 1987 Hardinge CNC lathe and 1989 mill are still going to be running when the 2016 Haas mill is on the scrap heap.

But as I said above, you first need to decide what size machine that you need.
 
I've picked up two used CNC mills, been happy with both so far. Bought a very lightly used Bridgeport with a circa 1981 Anilam Crusader II control (2-axis). I wanted a BP, not necessarily the CNC. The guy's shop was spotless, mill still had flaking on the table. No drilled holes in the Kurt vise or table. We swept the table with a DTI to check for table warp and checked the play in the X/Y ball screws with a 1-2-3 block and a DTI on the spindle. The head was quiet (it's a 2 HP variable speed), boring kicked out as it should, etc. Also checked spindle run out and "chuck" in the spindle with it fully extended.

I also bought a Tormach 1100 Series 3 this past summer. I asked the seller to check the play in X/Y/Z and while Skyping he ran it through it's paces. Same deal here, table/vises were untouched. Same condition shop here, could have eaten off the floor. His tool boxes were anally organized, so figured he took care of and took pride in his shop.

My first question to both sellers was "Why are you selling the mill?".

First guy was selling off his shop tool by tool. He was a tool and die maker and did some work on the side. He had at one time 3 mills and 3 lathes but was down to a South Bend 9A and the BP.

Tormach guy works at a production CNC shop. His boss offered him Saturday machine time to do his side gig (website: yourlittlecncshop.com). There was a job he ran on the Tormach that took 20 minutes per part. It took 3 minutes on one of the Haas' at his workplace. He pays his boss for the Haas time on Saturdays which was better for him than running the Tormach in the evenings.

Second question was "How hard is it to get to all of the lubrication points?". Both guys in my case had logs when they'd done any maintenance to the machines. The BP had nothing replaced on it, only scheduled stuff was when he'd filled the table oiler and did the BP-recommended head oiling. Tormach guy had a pretty extensive log, WAY more than I have done. He regularly checked the play in the ball screws and replaced the Y-axis when it got to 0.003". He also replaced the spindle after some number of hours (don't recall the number). He said he was one of Tormach's Beta-Testers for PathPilot releases. I called Tormach, they confirmed he was a Beta-Tester.

Long story longer, I looked at a BP 10 years ago that had a multiple drill/mill marks, Swiss-cheese vise and a very loud head. Asked the guy my lubrication question on a Heavy 10 lathe in his shop and he replied, "Easy to get to all of the lubrication points. I just don't worry about it." His shop was a pig sty also, so I didn't buy the project.

Good luck with your search! You will love having CNC. Makes so many things easier and quicker to do. Plus it'll keep your brain active learning something new.

Bruce
 
Chips O'Toole said:
When people go to forums and ask for opinions on low-cost machining centers, someone usually says, "Instead of buying that toy, you could spend less and get a used Haas." Something like that.
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I know nothing about CNC but unfortunately have become very familiar with this attitude.

I think you really need to look at what you want to do and don't put too much weight on the guys dismissing a machine as a toy. Maybe it is a toy for what they do, but it may be more than enough machine for you. I'm not saying to ignore advice, but you need to weigh it for value. First hand knowledge and specific issues are well worth listening to, but general "China junk", and "toy" statements are pretty worthless.

CNC machines come in many sizes from tiny mini-mills to machines that you could park a car on the table. Used machines can be a huge savings but also a gamble if you don't have the experience to evaluate one.

We often hear "Buy once, cry once", and I agree with that from a quality perspective, but not necessarily size. When you are just getting started and really don't know what your plans are, starting small (much less expensive) and learning can be a good option. Much less to lose if the hobby isn't for you, and easier to sell if you decide to go all in and go big. After a year or two of using a machine (any machine) you will have a lot more confidence about looking at a used machine. It also gives you something to learn with even if it doesn't meet all of your expectations.

You can find many posts here with people wishing they hadn't spent years looking for "the one" that great deal on their dream machine when they could have been making stuff with "good enough" until they found the perfect deal.
 
Over the years I have come across quite a few "works in process"... where someone bought a CNC mill in good shape with antiquated controls and tried to retrofit the mill with more modern controls... then gave up. These "works in progress" seem less common lately. I wonder if that is due to the CNC hobby market maturing and conversions being easier with more off the shelf parts and a better knowledge base online?
 
Chips O'Toole said:
It's not really possible for me to examine a CNC machine and evaluate it myself, which is why I posted the thread. If I could do all those things, I'd already be an expert, and I wouldn't need help.

There really is no solution, except for paying hundreds or thousands to have other people help me. I can't go to local shops and ask busy strangers to ride around with me and look at machines in exchange for beer. They'd think I was a stalker.

It's encouraging to hear that shops get rid of machines that aren't worn out, but all I've ever seen in Florida were old machines, like pre-2000. Imagine how many hours a production machine racks up in 20-30 years.
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I wouldn't underestimate your abilities just yet, if you're going to run it then it makes sense to learn something about them before you start shopping. I've recently started this online program from Titans of CNC and think it might be worthwhile if you haven't already been through it.


It's creative commons licensed and from what I can tell the guy's heart is in the right place. You will definitely learn some stuff that would help evaluate machines if you want to do it yourself. Most CNC machines that are worth buying will be under power and available to check out before buying. Also, as Jim said dealers do have a reputation to protect and most won't waste their time in something that's straight out junk since they buy at or below scrap value.

Also, don't hesitate to reach out to folks on this forum who have been where you are. This sickness is only treated by helping others get into it as well. ;)

It sounds like you are willing to spend a reasonable amount on a machine that will do what you want so you'll be way ahead of folks who are just looking for the deal of the century. Like I said earlier, the first step will be walking out to your electrical panel and seeing how much power you have. Once you've done that it's fairly easy to say you're looking for something say 5hp and below depending on what you can get to your shop. If you're willing to pay for something good then stick with the brand names that are still in business. Often manufacturers will have records on machines in addition to what the seller has kept and they can tell you if parts are available.

If you are like many and don't really have space/power for a full blown VMC then the retrofit market is definitely worth looking into. Either buy new or used and convert it yourself. You'll know just about all there is to know about your particular machine if you go this route. Also check your local community college for classes, CNC operators and programmers are in demand and most areas have active training programs. If you can get your feet wet this way you'll have a whole lot better chance of getting what you want for your home shop.

These are just a few ideas, this forum is super helpful and easy to deal with but there are others more focused on production (Practical) machines where you can watch experienced folks discuss and debate what used VMC's are suited for which jobs.

Good luck and keep asking questions!!!!

Cheers,

1ohn
 
The thing is, learning about running a machine would not make me capable of checking out a used one. It would probably help me reject machines that were hopeless based on obsolescence, however.

I know about Titan Gilroy. I like what he does.

I know a small amount about CNC. I actually turned a mini lathe into a CNC lathe. Then I found out it was pretty useless without ball screws. Basically good only for wood, and who needs CNC for wood?

If anyone else is considering a lathe conversion, my advice is to forget it. The lack of versatility is a dealbreaker. A mill is the only way to go.
 
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