View Full Version : Commercial CNC machine lifespan?

20-01-2014, 06:39 PM
In the near future I will be looking for a 4 Axis CNC milling machine and a 2 Axis CNC lathe. Both will need to have repeatable accuracy in chromoly stainless steel and Titanium. The easy bit is knowing what capacities and capabilities I need them to have, the hard bit is knowing whether to buy new (horrendously expensive) or second hand (lower price but reliability and remaining precision unknown).

If I was comparing a new or second hand car, well I have the experience to judge how age and mileage will effect the functionality of a used car and work out if it is still fit for purpose, but I don't have this knowledge for commercial CNC machines. The price difference between new and second hand is a lot and buying new will dramatically increase the time it takes to get my startup company into profit. On the other hand buying a second hand machine that was constantly breaking down or had lost its repeatable precision would be pretty dire. I appreciate this may well be an impossible question to answer but it'a still one I need to ask :joker:

How do you judge the effective lifespan of a commercial CNC machine? I realise I can rely on the advice of the various companies that deal with second hand machine tools, but I have no way of judging whether their advice is similar in quality to that of some second hard car dealers :suspicion:

Can anyone recommend a trustworthy firm or failing that give me some general guidelines?
Best Regards to all

20-01-2014, 07:37 PM
Welcome to the forum Sarah.

I can't help with your specific question but there are one or two here who can and I'm sure they'll be along shortly (JohnS?) as CNC is a hobby side for me. But with my other 'management consultant' hat on (and some experience as both exec and non-exec directors of high tech start-ups) I'm intrigued by why you want to buy machinery for a start-up rather than sub-contracting work out initially, and who is going to use these machines? Feel free to PM me if you don't want to discuss in a public forum.

20-01-2014, 11:32 PM
Hi Sarah, Can you tell us more about your business and how you plan to use the machines?

21-01-2014, 12:05 AM
Sarah Like Cars the condition all depends on how hard they where driven and same applies here really so the only way you'll really truly know is by speaking to the operators or the Engineers who service them or buy direct from the source owner and trust they tell you the truth about how it's been driven.
Dealers are dealers they will always bias the information they pass in there favor to make the machine more attractive.!!

Regards new or second hand then I can't help has there's so many variables and very specific to the machine and the use your putting it too and what they were doing.!!.
What I can say is I have an friend/acquaintance who runs a CNC shop that's running 24/7 both VMC and Lathes and I wouldn't buy is old machines has they are nearly ready for the scrap heap.
The problem comes from the fact they are so very expensive they need to be run constantly to cover the cost and every minute stood still cost's money. This will also apply to other CNC business's so should give a guide to the kind of life most manufacturing machines will face.

Also realise that there are other advantages to New machines other than being shiny and reliable.? . . . Often they are more efficient so cost less to run and increase Productivity. The same friend recently bought a new Index 5 axis lathe that is producing parts at 3 times the rate of is nearist newist machine that is less than 5yrs old and cost's less to run per hour.

Have you looked at leasing.?

21-01-2014, 09:04 AM
The best description I have heard/read ... is ..

2nd hand CNC's are like 2nd hand haulage trucks ...
They were bough new, and bought for a purpose
Once they no longer are fit for that purpose, they enter the second hand market !

Yes, they are cheaper, and still viable to those that have the knowledge to 'tinker' with the machine once a week/day/etc. to set it back to the best it can be.

but usually they have been worked hard, and you can not tell how it will work for you until you try it !

As others have said ... let us know more about what you want to do, and you will get more precise answers :)

Good luck !

Peter Griffin
22-01-2014, 10:46 PM
Before buying second hand, always reference the serial number of the machine with the manufacturer. This will at least tell you if it has been regularly serviced.

23-01-2014, 12:55 PM
Hi and thanks for the question. I am designing products and need to produce small runs to test and refine the prototypes. It's more likely that we will look to licence out our designs than to make large numbers ourselves though we may produce small numbers for commercial sale if we have got the size of the market wrong :chargrined: Best regards Sarah

23-01-2014, 01:04 PM
Thanks Jazz, I haven't considered leasing, largely because I have seen what leasing companies have done to friends startup firms when things didn't take off and they needed to cancel the lease. Images of vampires spring to mind :glee: Perhaps I am too cynical and there is such a thing as a ethical leasing company (along with unicorns and tooth fairies) :ambivalence:

23-01-2014, 01:05 PM
I forgot to mention that I need to machine complex 3d surfaces so for those elements of the work manual machines are out.
Best Regards Sarah

23-01-2014, 01:11 PM
Thanks for this, your advice is appreciated. That description sounds wise. I thought designing stuff was going to be the hard part, what a great deal I have to learn :cower:

23-01-2014, 01:15 PM
Before buying second hand, always reference the serial number of the machine with the manufacturer. This will at least tell you if it has been regularly serviced.

Thanks Peter, is it your experience that manufacturers will tell you the service details of machine? I had presumed that most would be too busy.
Best Regards Sarah

23-01-2014, 02:19 PM
Whilst the manufacturer will probably be quite helpful, they would also like to build up a relationship with you in the hope of selling you an upgrade or even a new machine. After the first user, it is likely that the 2nd or any subsequent user has not used the manufacturer for routine servicing, but that does not mean that the machine has not been regularly maintained. As a general rule I think that the condition and price will be your best guide - if a machine is really cheap, be aware that you may have to spend some money on it. I bought an older "scruffy" cnc router (spares or repair) and it is now back in everyday use and doing a good job. A new machine would have been far nicer, but a. funds were not available and b. the work would never have justified the expense.
As you intend to do mainly 3d work, the newer machines are likely to be far more suitable due to much improved software and modern electronics. G.

Peter Griffin
23-01-2014, 07:38 PM
Thanks Peter, is it your experience that manufacturers will tell you the service details of machine? I had presumed that most would be too busy.
Best Regards Sarah
In the past we have done this with Matsuura,Mazak & Bridgeport all have been very accommodating.

24-01-2014, 01:21 PM
Thanks again Peter, this is really helpful to know.
Best Regards Sarah