Feasability of repairing a Mazak VQC 15/40

Hi guys,

I got put on to a 1980-something Mazak VQC 15/40 by a friend of mine. Apparently the small shop who owns it is just tired of it taking up floor space and just want it out. I went to look at it today and it seems to be in decent physical shape for its age. From what I can find about these machines:

6k spindle
40 taper
16 tools
10 HP spindle motor (he said it was 15 but I haven't seen any with more than a 10).
This one has the M-2 controller.

They think it has an electronic issue. Apparently they hired someone to work on it and when he couldn't figure it out he gave up. He mentioned they put about $6,000 into it before they just let it sit. He booted the control up for me and it gives a "22 SUM CHECK ERROR" alarm. This is the only alarm it gives so there may be more buried underneath that. A few quick google searches show this might be an issue related a parameter(s) and or battery?

I am going to keep researching, but any knowledge/input would be awesome. I am a one man shop with one VMC, so being able to get this working and added to my capacity would be amazing. Especially at the price.

Edit: In regards to memory, he said it is pretty limited but had no idea what the capacity was. I don't have a huge need for 3D milling (which he said it is not capable of), but I do use a lot of HSM/trochoidal toolpaths which result in decent sized programs. Any idea what the memory capacity is?

Thanks!

IAmAlex said:

Hi guys,

I got put on to a 1980-something Mazak VQC 15/40 by a friend of mine. Apparently the small shop who owns it is just tired of it taking up floor space and just want it out. I went to look at it today and it seems to be in decent physical shape for its age. From what I can find about these machines:

6k spindle
40 taper
16 tools
10 HP spindle motor (he said it was 15 but I haven't seen any with more than a 10).

They think it has an electronic issue. Apparently they hired someone to work on it and when he couldn't figure it out he gave up. He mentioned they put about $6,000 into it before they just let it sit. He booted the control up for me and it gives a "22 SUM CHECK ERROR" alarm. This is the only alarm it gives so there may be more buried underneath that. A few quick google searches show this might be an issue related a parameter(s) and or battery?

I am going to keep researching, but any knowledge/input would be awesome. I am a one man shop with one VMC, so being able to get this working and added to my capacity would be amazing. Especially at the price.

Edit: In regards to memory, he said it is pretty limited but had no idea what the capacity was. I don't have a huge need for 3D milling (which he said it is not capable of), but I do use a lot of HSM/trochoidal toolpaths which result in decent sized programs. Any idea what the memory capacity is?

Thanks!

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It is microscopic, you will need to drip feed it.

1980's something is a huge gap, the exact year could make a big difference. CNC technology grew leaps and bounds in the 1980's. First question how much will the cost of the machine be for purchase price, rigging and wiring it in? Now compare that to the value of a similar machine in decent running condition. I am a Fanuc guy so I can only speak in generalities. Are parts readily available at a decent price? Is there a place you can get boards tested at a reasonable price? If the machine is too far gone to bring back to life at a reasonable price what can you get out of it selling it whole or parting it out? If it is just simple economics, whether it is a good gamble or not can be figured out pretty easy. You also need to research the history of the machines if one of that model and age commonly turns into a money pit it would be best to pass.

I ventured out into owning CNCs buying some poorly designed cheap pair of Mid 1980's vintage CNC Lathes a little over a dozen years ago I figured I could at least make one good one having two of everything. I dove in head first without researching, boy was I sorry, they burned money and time that set me back quite a bit. So far buying older CNCs (10-20 years old at time of purchase) I have purchased 3 good ones and 4 money pits. It is also really tough to decide when to stop spending money and when to cut the cord.

Dualkit said:

1980's something is a huge gap, the exact year could make a big difference. CNC technology grew leaps and bounds in the 1980's. First question how much will the cost of the machine be for purchase price, rigging and wiring it in? Now compare that to the value of a similar machine in decent running condition. I am a Fanuc guy so I can only speak in generalities. Are parts readily available at a decent price? Is there a place you can get boards tested at a reasonable price? If the machine is too far gone to bring back to life at a reasonable price what can you get out of it selling it whole or parting it out? If it is just simple economics, whether it is a good gamble or not can be figured out pretty easy. You also need to research the history of the machines if one of that model and age commonly turns into a money pit it would be best to pass.

I ventured out into owning CNCs buying some poorly designed cheap pair of Mid 1980's vintage CNC Lathes a little over a dozen years ago I figured I could at least make one good one having two of everything. I dove in head first without researching, boy was I sorry, they burned money and time that set me back quite a bit. So far buying older CNCs (10-20 years old at time of purchase) I have purchased 3 good ones and 4 money pits. It is also really tough to decide when to stop spending money and when to cut the cord.

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I appreciate the advice. I am familiar with all of these issues and am researching all of it. From the sound of it, they are probably willing to get rid of the machine for next to nothing as long as I pay to get it out. Rigging is only cross-town so it might cost me $1,000-$1,500 to get it picked up and set back down in my place. The reason for this thread and my own research is to try to determine what the chances of this being a money pit actually are. Can it be fixed simply and these guys just don't have the knowledge/determination to do it? Or is it truly beyond repair? This is what I am trying to discern. I have put a lot of hours and elbow grease into my 17 year old mill and it runs wonderfully. I'd be happy to do that on another machine if I feel that the issues are not irreparable.

IAmAlex said:

I appreciate the advice. I am familiar with all of these issues and am researching all of it. From the sound of it, they are probably willing to get rid of the machine for next to nothing as long as I pay to get it out. Rigging is only cross-town so it might cost me $1,000-$1,500 to get it picked up and set back down in my place. The reason for this thread and my own research is to try to determine what the chances of this being a money pit actually are. Can it be fixed simply and these guys just don't have the knowledge/determination to do it? Or is it truly beyond repair? This is what I am trying to discern. I have put a lot of hours and elbow grease into my 17 year old mill and it runs wonderfully. I'd be happy to do that on another machine if I feel that the issues are not irreparable.

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If you invest enough money and time anything can be repaired, what is it worth to you?

Checksum errors are usually related to the memory modules on the CPU board. I would rule out new parts. If you can find someone with the same machine, you might be able to copy the memory from that machine and burn new chips for yours. I'm not familiar with Mitsubishi controls though, so I could be way off.

Crude explanation is that the computer stores information as 1s and 0s. The computer keeps track of the sum of those 1s and 0s for a certain section and when the computer is powered back up, it compares the sum it saved to the sum it is now seeing in that section of memory. If the two numbers are not the same, you get a checksum error.

If you don't get any responses from current or past owners of a like machine here in a reasonable amount of time I would ether get a hold of the build list on the machine if available or make my own. If it was a Fanuc the part number on the boards are easily visible. I would write them down and see what price and availability was, with Fanuc parts just Googling turns up numerous places listing prices for warranted exchanges. The spindle drives are usually the most pricey. If you can't turn up a lot of parts I would be concerned, it is a crap shoot to send something out to a repair place that doesn't specialize and stock exchanges, don't ask how I know that.

Good idea on the build list. I'll look for some of the more major components and see what I come up with for availability/price.

From what I've found in older posts on PM and another unmentionable website, it looks like the 22 check sum error is usually related to a dead/dying battery causing lost parameters. I also saw mention that if you reset the "low battery" alarm too many times (no idea what that alarm code is), the control will lock the machine and throw a 22 check sum error. I have no idea if that's accurate, but they did say it was throwing an alarm before and they could reset the alarm and it would run.

Hope they have the parameters backed up, Googling shows that Mazak doesn't have them for that model.

I was finding the same thing. I am going to call the owner and ask tomorrow. He said they have all of the manuals so fingers crossed they have the parameters as well.

I have the same machine in my shop. It was my first CNC mill bought in 2003. It is my favorite machine for onesy twosy stuff. If you need a set of parameters I can help you out.

Thanks enslow. That would be really awesome. If I do end up buying the machine and can't get ahold of the parameters, I will definitely take you up on that. Do you have the M-2 control?

It looks like a neat little machine for the time it came from. I have another bigger mill that I can do all of my more complex work on (3D, etc). This one would just be really handy for the one offs and smaller, simpler production jobs.

I've bought used older machines and been lucky.
Next purchase regardless of age(and I'm sure it won't be new) must have a copy of the parameters and the electrical schematics before I pay for it.
Time and money spent getting these after the fact will kill a "deal" real quick

I would check out the servo drives, and do some research on driving them. I am not sure why more people don't pick up these great pieces of iron and throw EMC on it. I have always been lucky buying older stuff and getting the electronics to work, but for freeish I would seriously consider tossing the controller and retrofitting something new if you have 1K or so that you could spend... then you have no memory problems, no 3d problems, no drip feed parity or making a cable bullshit, none of that stuff.

It sounds like this is more of a hobby/ free time thing at this point. If I didn't have to make money right away with the machine, I would be super interested to try throwing a new control in something.




...and also, you should document it well on PM so then I can learn from what you do so when I decide to do this in a couple years, someone already did it.

Thanks again for all of the input guys. All good thoughts to consider.

It sounds like this is more of a hobby/ free time thing at this point

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Yes and no. I am running a business and therefore would obviously like this machine to get up an running as soon as possible to start making me money. However I do have another machine that runs every day that I have been doing just fine with. So if it took me some time to get this one running, it wouldn't be the end of the world. The worst thing that would happen if it never ran would be maybe some lost free time of my own and whatever money I put into it to get it here. What I am not going to do is put tens of thousands of dollars into an old machine that may never work.

As far as retrofitting, that isn't something I'm even researching right now. If I do get it up and running, I may do some research and see if a retrofit seems like a logical, cost-effective idea. I'm familiar with the concept but I have absolutely no first-hand experience when it comes to performing one.

And whether I end up doing a retrofit or not, I would be happy to document my repairs here. In the time that I've been in business I've found countless threads here going years back that saved my ass when something broke down.

Going back to the EIA option; if the machine does not have this option, does that mean it cannot run any programs that aren't programmed at the machine on the controller? I am pretty green when it comes to different programming languages and have never operated a machine that was unable to run programs written with a CAM package and posted out. I have no problem learning whatever different programming process I may need to, but I would like to know what the limitations of the machine are in this aspect and what I will need to learn.

sudsy55 said:

All well and good to retro fit something but won't be close to the ease of programming as Mazatrol for at the machine programming

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And it would probably never work right. It's pretty rare you see a DIY retrofit machine that actually fully functions (like coolant, tool changer, proper ladder replication, etc), for the simple fact that it's a metric shit ton of work to finish a project like that. Most people get them just barely running, make some parts with a poorly-tuned servo loop, and call it a day.

Okay, I stopped over again today and took a look at the service documentation they kept on the machine. Here is what I found:

(2012)
22 Check Sum Error
Repair tech was unable to wipe CPU, sent entire controller back to Mitsubishi for repair.
Mitsubishi found the following:
-PCB M2B FX784-8 RAM ROM
Failed pattern read test caused by corrupted s/w
Repaired and passed all tests

-PCB M2B FX763 I/O
Failed testing
Repaired shorted octal and relay I/C
Passed all tests

PCB M2B FX784-9 RAM ROM
Failed pattern read
Erased and rewrote s/w
Passed all tests

All 3 of the 3.6V batteries were also replaced.

The machine ran properly again for some time. In 2014, there was a solenoid valve replaced. It ran for a few weeks and quit for good. It has not been run since sometime in 2014. The final issue was that the machine would boot up and you could zero all axes, but could not perform any movement after zeroing. He did not remember the alarm that that issue caused.

The alarm the controller shows now is the 22 check sum error. I am guessing this is because the machine was unused for so long that the batteries lost voltage. From what you guys have indicated and what I have read elsehwere, the 22 check sum error is one of the easier issues to fix. Knowing how long it has sat I'm not terribly concerned about the check sum alarm.

What I am hoping to figure out now is what could be the possible causes for the axes not moving after being homed. It seems odd that they would move to home but not move after that. I would think any motion issue would be an all or none issue, meaning either it will move anywhere or move nowhere. Any suggestions would be great. No issue is "too simple" to mentioned; I say this because I saw service reports in the folder where they paid service techs to clean dirty home position sensors...

Edit: I did not see any work reports for the axes movement issue. From what they said, the person they had relied on to repair it in the past wasn't interested in working on it anymore.

You might consider asking to owner for the repair guys name and give him a call just to get insight into what he remembers about the machine.
Could have been frustration on the owners part that make the tech walk away. Good luck.

Good call Dan. I remembered the name from the service reports so I gave them a call. He remembered the machine when I gave him some info. Basically verified everything that I found in the reports. He did not recall having ever worked on the axes motion issue so I am thinking the owner may have just stopped putting money into it when that came up.

Given the info I have got from the owner and what you all have provided, I think I am going to pull the trigger on this machine next week assuming he and I can agree on a price, or lack thereof.

If I do get the machine, I'll gladly document any maintenance that I perform here on the forum.