Watch Out for These Red Flags in Used CNC Machines! | Machine Shop Talk Ep. 92
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- เผยแพร่เมื่อ 2 ต.ค. 2024
- If you’re thinking of starting a machine shop, new equipment may be too far out of your budget to be feasible. Used machinery is an excellent way to get into the game or build your capacity - but what are some things you should watch out for when browsing the pre-owned market?
On this episode of Practical Machinist’s MACHINE SHOP TALK, Ian Sandusky from Lakewood Machine is back to help a poster on the Practical Machinist forums who came on with exactly this situation on their hands.
While the used machine market can seem perilous at times, there are certainly use-case scenarios where it makes sense to bring in used CNC machinery. Whether you’re looking to increase production, add capabilities, or break into the CNC market - there’s usually a good option in the pre-owned world to help you out.
What are YOUR red flags to watch out for when it comes to buying used CNC machinery? Let us know in the comments below!
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I'm probably going to get torn to pieces by saying this, but read the paint. Paint on the inside of the machining area is a good indicator of how many chips that machine has made, and how hard those chips were coming off of the workpiece. Paint on the door contact surfaces on mills and lathes, and on lathes just under the door where operator's pants rub the paint when they're changing parts. These are all good indicators of how hard that machine has been run. I was looking at a mill a while ago with reasonable hours and the inside looked like it was sandblasted. The machine I ended up buying was a 2000 Hardinge VMC600 and the factory paint inside the machine is completely intact. That Hardinge has been a rockstar for nearly two years now with 19200 baud drip feed.
I don't think you're wrong at all! If I see a machine with insanely crazed windows, a toolchanger that's been stripped of paint, and an outer enclosure that has the paint flaking off - it would give me serious pause as to what's wrong UNDER the hood. Same thing with a car - how often do you see a vehicle ridden hard and put away wet on the outside, with a sparkling new engine?
Honestly not always true. I bought a machine that had decent paint for its age and even had a tech inspect it. Turns out he didn't check the turcite and it's trashed.
I was looking for a cnc lathe to make parts for my products. I found a clapped out 30 year old okuma CNC lathe that has sat for 10 years. I took the risk and bought it for 3k. It took few months to sort it out and fix some problems. Been making good parts for a year now, without any issues. Machine is slow for todays standard, but im in no hurry. Having this capacity in my shop has boosted product development speed. I can design new parts in the morning, cut them out after lunch and try them in the evening. If you are designing and making your own products, having this kind of capacity has massive advantages.
Throw indicators on the machine. You can mechanically identify any issue. Then look at the control if it can be serviced. Parts and availability. Its simple. Stick with the same brand in your shop. You can transfer parts over.
Machines that are not able to be shown under power, ESPECIALLY machines that have been powered down for many months or years... I argue that they are worth their weight in scrap steel, or should be regarded as parts machines.
If you can't see the machine start up, move the axes, check backlash, run the spindle (and warm it up), clamp and unclamp a tool holder, to a tool change, you should assume you won't be running any jobs immediately before putting time and money into fixing it.
I think 20-30yr old machines can definitely be worth it, you just have to know exactly what you're getting.
I was just lucky a traditional shop owner in the neighbourhood had a CNC in his shop and we asked him why he's not using it. He said he has no operator but the machine is absolutely okay. OK OK I checked the machine - it did not even power on, checking the compartment - the main controller was missing - asking him where that part is he said oh I forgot I gave it to the service technician 3 years ago.
Anyway what was wrong:
- defect / dirty encoder on X axis
- defect / dirty encoder on Y axis
- dirty / coated encoder on Z axis.
- X endstop switch is clogged
- Z endstop switch is clogged
- Y endstop misaligned
- Y amplifier defect (CPU is defect)
- air pressure cables are all defect
- Controller lost all the settings
- Tool changer switch clogged
- Tool changer quick eject button was not working properly
- Toolchanger macro was gone
- Piston for toolchanger sealings were defect
- Spindle orientation was wrong
- two front bearings are defect
but yeah the machine was absolutely workable... it took me one month to fix everything and adjust all the settings.
there a you tuber call the CNC Repairman he has lots of great hints and tutorial on CNC and he has a video on buying used machines his videos are worth a look
He's awesome, he's a fantastic resource!
What to watch out for? 1, Did it have synthetic coolant in it? Cause if it did, the paint will be gone, look for rusty ways and way covers. If its covered in sticky brown goo, run...2, Control type, any thing Siemens is gonna empty your wallet. They own Acramatic, so be very careful with a Cinci or any machine with a pc2100. Their drives suck..., Next Yasnac, good control, same as Fanuc as far as usability, issue, Yaskawa hasnt made a control since 2002, they are outta the business. All the older techs have retired, you are on your own. 3, ask yourself what you really need. Speed is an illusion for short run work, consider the advantages to having a lathe and mill , more flexable then a mill turn lathe. 4, do not underestimate older well kept equipment. Ill take a 20 yr Mori over a haas anyday. Older equipment with modern tooling is eye opening. I had an old Brown & Sharpe vmc, old slow... that machine was incredibly productive with modern tools. 5, learn to fix your own equipment. There are deals , some free if you have the skills. All machinery breaks, matter of how and when. That shiney Haas is gonna break also, about after the last payment...kinda like that new truck you bought. Another point to keep in mind, as you look at newer equipment, everything is proprietary. Drive signals are digital, the options parameters are watchdog locked. One of the things I loved about a Fadal, with the exception of the castings and control boards, every other part could be bought from Mcmaster Carr and Digikey.
Yes, avoid full synthetic. I just spent a lot of money refurbing a Mazak horizontal cause it had run Cimcool full synthetic. I have done similar work to our other mazaks but this one soon as I went to pressure wash the goop off the panels it blew all the paint off exposing all the rust.
@@damientoomey1194 pull the way covers and check the condition of the ways and roller trucks.
@@Zeusspupp Z axis is pretty noisy. I discovered there was no lube getting to the ball screw nut, bearings and only a small amount getting to trucks. All metering valves have been replaced but the damage is done. Doesn’t affect finishes just sounds horrible.
When you do decide, make sure to hire a competent heavy equipment mover. Your forklift buddy might be good moving pallets but a mill?
Oh man, I've seen videos where people try to cheap out on it - you ever see a UMC750 do a backflip? It's not pretty.
@@iansandusky417 Good machine moving is not cheap, so that needs to be in the budget.
The guys I can never work out ??
Buy a brand new machine or near new, then hire the cheapest guy with the minimum amount of knowledge and equipment to do the job 🙄
Alot of good comments but one thing nobody ever mentions is the cycle start button, is it worn in the center or did someones nails dig in and remove the paint above it, this is a sign if alot of different setups (running blockwise)
Also are the programming buttons all worn out but the cycle start buttom is like new, also a sign it didnt run production. Stick to used Japanese machines and you will have less headaches.
If this guy needs a "hole drilling machine" - why not find a good used Bridgeport and do a 3-axis prototrak retrofit ? It will fit in his budget, uses tooling he already has, and will be fairly easy to run.
I think the thought was "why spend 3-9k on something without a pallet/tool changer, etc, when 30k could get way more productivity".
The guy has the constant work, so either no investment, or a slightly larger investment, is cheaper than something in the middle.
I have done well with older Mazak machines and they are very capable for their age and hold good size but after closely looking at parts a friend has made on his new dmg monoblocks it was just unreal. I don’t think mine could even achieve what he was doing at 8m/min.
Let’s just say you get what you pay for.
You buy an old machine that’s what you get .
It’s very symbol if you’re already in the trade know if the machine is any good or not .
Let’s face it machines are designed to cut steel and hog
If that’s what it did most of its life
Who cares that’s what it’s meant to do
If you’re not good enough to tell if the machine is good or not, and maybe you should consider doing what you do
Red Flag..
Second Hand HAAS VMC that has not already had the Spindle replaced ??
The main thing to do when buying Anything second hand.
Look & Listen ??
IF it looks like crap, it's probably had a hard life. ( much the same as some people, LOL )
IF something doesn't sound right either walk away or pay a Tech to do a full report on the machine your interested to purchase.
Some brands will have a service history from the dealer it was purchased from.
In some cases the history will drop off either because they haven't spent any money on the machine.
OR.
They decided to use an indepent Tech for all their servicing.
The reality. IF it's second hand it will cost more than what you paid for it.
Don't take it to heart.
Machines are not unrepairable.
Of course, NO one wants to spend more money than can afford to.
But, Welcome to Reality 👍
If it is Japanese with a Fanuc 6 or later control, you can see it running and it has with it a FULL array of manuals and schematics - it is hard to go wrong.
Older machines have limited memory. Modern machining needs more memory. If your prospective used machine doesn't have readily available DNC functionality, either already installed or you have a line on the parts, you will hate life. Point in case: I bought an Okuma Cadet Mate V4020. AWESOME MACHINE, I knew the original owner and it was actually the first machine I ever ran working in a shop in high school, but it had like 2.5k of program memory available considering the paramaters and stuff resided in the same memory bank. It had a 20 pot ATC but I literally could not have my CAM software post an .nc program that just did an M6 with offsets through the whole carousel because that took too much memory. I had to post each op individually and load it one chunk at a time. Okuma was all proprietary and they had zero dnc boards available 20 years later. It would have cost me twice what I paid for the mill to retrofit the control. My employer wound up selling it and I hated him for it because it was a sweeeeet second op machine with its 8k spindle, tight motion, and actual very low hours with a known single owner.
Oh I definitely understand this pain - I have to drip feed my 2005 VF5 for any kind of real modern toolpath or programs that run over an hour. You don't want to get into that kind of scenario if you don't have to.
If you are gunna use older machines you need to know how to gcode, otherwise it will be a battle
@@bryanbrown7403 you're missing the point. There wasn't enough memory to write the codes into the controller even. Even simple setups like spot, drill, tap a set of 30 holes on a plate couldn't fit. It was ABSURD how small the memory was on this machine
@@iansandusky417 this machine wouldn't drip feed. That was a separate controller board that went in place of the tape drive i also didn't have. I used to work at a shop where we drip DNC'd tons of 3D machining stuff on fadals and it was certainly not a pain compared to what i had to do to split up a program and run each block one by one. It was sloooow.
You had to switch modes on the controller from read to write memory, blahblahblah. DNC wouldn't work without that board and since Okuma was very vertically integrated, they made EVERYTHING in the machine and it was all oddball proprietary and NOBODY had the damn board I needed.
I would counter: the whole point of buying used is to save money. If the machine with enough memory to run off the control is $30k more than the one you drip feed all things the same, I’d drip feed in a heartbeat.
The best machine for the price when first starting out is probably a haas tm2. It has 40 inches on x. I'd buy it new if I had to start a shop tomorrow and throw it in my garage because it can run on single phase. You get all the memory of a new machine with the probing and such that a modern machine has. If you can make the monthly payment on a machine this cheap then
Check backlash, listen to the spindle. Those are pretty much the two key points.
Last machine i bought was a 2004 VF3 two years ago for 35k. It's been one of my best CNCs.
>properly maintained
Never. Even if you show me the paperwork, no. It wasn't. These things are made to work. Especially if they're smaller brands, or cheaper brands like haas.
100% correct. If a home gamer buys a used machine it gets oiled, wiped down and babied. If a company buys a machine it gets maintenance when it stops working.
@@joels7605 it gets REPAIRS, not maintenance.
@@orangedream267 Honestly, more often than not you're correct - unfortunate but true! Too many shops don't prioritize maintenance and just hop on things when they break to the point the machine is no longer running.
Look at the condition of the machine. Does it have tooling. Is the tooling in good condition, or is it sitting in a pile on the floor? Does the spindle taper have a bunch of chips welded in it because nobody wipes the damn tapers? Is the paint blown off of one wall of the enclosure where someone was clearly running parts made of hell metal? Has the coolant tank ever been cleaned? Does it look like the lube has been maintained? Do they have lube? Where's the manuals? Is it plugged in, if so how does it sound - tool change, run spindle, move axes around. Is the electrical cabinet intact or did a meth user try to steal power from inside? Has anybody thrown a part and busted a panel or window? Blood stains? Does it leak on the floor? Is the floor clean? You can tell a lot about a machine based on the environment it's in IMO...
This is incredibly true - great advice!
Lol. I had my local used machine dealer say almost those exact words "if you don't like it or need it after a couple months, I'll buy it back"
Almost like renting a machine
can you give me an advice to find my firts customer?
I would and have purchased used machines with good success. But Absolutely don't take a chance. Run a ball bar test on any machine and learn what the machine is doing.
my main machines are a 10" chuck Ecoca lathe and a Bridgeport vmc600, both 22-23 years old and great machines , the vmc a couple of drives have gone on it and luckily we had spares from a scraped machine, the lathe in the 17 years i have used it the coolant pump went , we have a 8 year old goodway lathe that has had £1000s spent on it prob about 30-35k the other one nothing at all, been a good machine, YCM mills we have 3, all bought at the same time all, all assembled wrong so our tool rep told us so all needed new ball screws an bearings, spindle bearings went in all 3, during the warranty we had a guy out for at least 1 of them every other week lol, they work ok now. As for 2nd hand i would go for a 2nd hand quality make machine, the old bridgeport i use, still loads of places that can fix it, all the spares still on the market, used fixed drives or new drives easy to get..
Shop where i work at, we got 2 Bridgeports vmc600, one of them with 4th axis. I've got them connected to Fusion 360, servo lag is on and they run like a champs. Machining stainless 316 very often with no problems. I like Bridgeport vmc1000 more because of size and i believe 15kw spindle in it? But definitely reliable machines considering the age.
It’s boatload on NO LONGER AVAILABLE for example we had one that the battery holder failed on and it wiped out ALL the parameters
Oh man, that's an absolute nightmare! All that for a nine volt!
Loved this video. But “late model” means “latest model” aka modern.
What about buying newer chinese/cheaper machines?
Nothing wrong with buying a New Chinese machine ??
But, you might be best to know something about Mechanicals and Electronics.
For when the time comes when you can't find a Tech that can or wants to help you ??
Servicing would be a nightmare. Get a torrmac. Cheap and new.
@@SuperVladamere Tormach is Chinese...
Shin Nippon Koki, Anything Nissin. Built like a tank. All the old Okuma stuff was built to last with solid rigidity. The bones of these are worth retrofitting controls, spindles and servos too in the future with their solid box ways and castings, Capacity, etc.
Its very easy if you want to buy a used Machine you should get a repair technician to go help you test them before buying
hard to beat the value of a fadal. i have 2
I've heard they really stand up over time!
@@iansandusky417 and you can get parts. Not as fast as newer ones but not a bad way to start a +-.005 shop
I worked at a mold making company that had 5 roughly all manufactured in 1996. Ran lights out 90% of the time, very few problems considering age and run time. Still going to this day, 3 4020s and 2 6030s.
If the push buttons are worn thru to the point where they barely work, there are issues elsewhere. Also, if there's no documentation, ie, manuals, parameter sheets, build sheets, etc. WALK AWAY.
Hey Ian, thanks for the video!
Do you have the link to the thread from the practical machinist forum?
lots of larger milltronics machines in good shape out there for half that price. plus they can be used manually. and conversational programming.
I stated with 25k mought a vf2 a rpc, a small air compressor, and a 7x12 bandsaw as well as a laptop. Started off small and made it work.
Not only depends on crashes and what material was cut, also what kind of machining.
Die making and small contouring wears down slideways and ballscrews much faster than long continuous cuts in one direction.
Hardened steel and small aluminum makes nasty chips that get into the ways, you can pretty much be sure to have seized ways on such CNCs after 30 years.
And such clowns that occasionally cut wood, fiberglas, pertinax... or use wood to test their CNC programs on CNC lathes with coolant, dust and coolant crap everywhere, especially behind the way covers that rusts there over time, usually the ways and not the stainless way covers :-/
Machines that were often used with flood coolant are a bad choice generally, that stuff gets everywhere, dries up and leaves nasty goo everywhere, that rusts the machine over time.
Not to mention oil displacement on slideways, i.e. seized ways over time.
I'd say hardly any machine is run with dry cutting exclusively (no coolant). But fun fact is I have an old manual Eart German mill (WMW-Heckert) and the manual says if you have to use cutting fluid, only use straight oil because water based fluids are bad for the machine.
I think the James Park guy from South Korea here on YT did a repair on a machine replacing the linear guide carriages and it showed the total havoc created by coolant. First, the seals fail from wear and once the coolant enters it's all downhill from there. He did not replace the guideways themselves which was a mistake because they were corroded. I think he had some kind of system hooked up where they would oil the carriages by central system but this is also a bad idea as these systems are not designed for it.
Get a multi head drill attachment.
Can't wait to find out what's wrong with the $2500 ST30 i just bought!
To be fair, at that price it's almost exciting to see just what exactly a $2500 ST30 is all about! If it doesn't instantly self-ignite, I think you're in good shape!
@@iansandusky417 I've repaired a couple of bunky machines so I come in with pretty low expectations! But even if I gotta spend 20k on it, it's still a bargain! Btw that's Aussie dollars.
That's not tipycal , you know people don't ya ?
Never buy a used machine from a guy that wears his cap bassackwards.
what about a vintage 70's muscle car?
@@CraigHollabaugh Nope. Only pot & crack
@@funone8716 good point
This was a useless video lol
Never buy a haas, thats about it, DMG dont give any info on their old machinesand parts are expensive, but do reasearch before buying.
Anything with Haas in the name
Sorry, is that good or bad thing? I have never used a CNC machine, yet.
@@Shrub4Treez bad very bad very very very very very very very bad can you see where I’m
Going with this
@@chrisyboy666 Hahahaha yessir! Thank You for the heads-up I'm not looking to buy but I do recall seeing Haas dough mixers in one of the bakeries my Grandpa used to work in...kinda figures that they would not be able to "cut-it" when it comes to metal. Thanks Again! : )
I disagree. If you're going to buy an old clapped out machine for $5000-$12,000 just to get the ball rolling in an effort to make money/ get your business off the ground, haas is good because they are easy to work on, and you can get 90% of the parts from haas still besides some processor boards. but those can be repaired. I would not buy a new haas, or spend $40k for a used one, but for a starting point I think they're great. I started with a 94' vF0 and 99 VF0e. Not the best. They were beaters, but they made good parts and proved my business model. We now have 4 Doosans from year 2019-2022.
Check backlash with an indicator, inspect the machine in person, see what everything sounds like (rapids, spindle, feeding, etc.). No old beater is going to be perfect.
Watch the Z counterbalance on those VF0's. A coworker almost lost his hand when the spindle dropped suddenly one day on his '96 while he was doing a setup.