Mori DCG NH4000 Spindles
Has anyone had much experience with these machines? I am programming for two of them and the spindles don't seem to last more than 12-18 months without needing to be rebuilt. We have had some minor crashes, but none have been very hard. No spindles have ever full rapid crashed into anything that I am aware of. One of them runs 14000 RPM virtually 24-7 however. Any information as to whether or not this is normal and ideas on how to make them last longer is appreciated.
Thanks,
Travis
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"minor" is relative. 14K spindles are a little sensitive. I would turn the timer up for air/oil mist so it gives a shot of oil a little sooner. That has helped other machines, but too much will cause damage. You also need to make sure the chillers are working and the filters are clean. I personally have not had one fail, but i've been away from service for some time.
Of course I understand that 'minor' is a relatively loose term, but then so is 'a little' when you mention turning up the air/oil mist (that could also cause me more problems). I appreciate your thoughts, and I will talk to our service guy to see what he thinks about it.
The machines have taken cuts heavy enough to overload the B axis, and we have tossed a couple small parts out of workholding because of aggressive cuts. We had a part get thrown because it didn't get clamped down before the program was started. Maybe 2-3 bumps per machine at 25% rapid rates during setups into aluminum subplates that we use for fixturing. Is that specific enough to expect some help? I don't really know what to tell you... our Mori verticals have 14K spindles and seem to hold up a lot better, but they aren't run as many hours per year. I am mainly curious as to whether or not my expectation of the expected hours of life from a spindle is accurate or not. Maybe someone can give me some information as to what I should be able to expect as an hours basis on the life of a 14K spindle in a Mori DCG machine. Then I can look into what we may be doing to cause our life to be less than that, if it even is. For all I know, we are getting better than expected life out of these spindles.
Again, thanks for the thoughts, hopefully this post will clarify the vague description of minor crashes a little better.
Travis
Same issue...
Tminnig,
Did you ever find anything out on your original post? We have an NH4000 and the first spindle went out after 10 months (with only 284 cutting hours) and we just lost another spindle after 17 months (1,740 cutting hours). We have only been cutting aluminum on it and haven't had any crashes or anything that would lead us to believe that the failures were self inflicted at this time. Your feedback would be appreciated.
Hello inthecut. I never did get any other response, except that our machine dealer is completely convinced it's our own fault, and of course, no one else is having these problems. Sorry if I come across a little cynical... I am.
The only thing we are doing right now is purchasing a tool balancer. We have a 20K RPM HSK machine being delivered tomorrow, so the tool balancer became necessary anyway, but I'm pushing management to buy us a CT40 adapter for it so we can balance the holders for our 14K machines as well. I can't really tell you that's the problem, but that's my current idea to try and alleviate the spindle wear. It seems reasonable to me anyway...
It's really frustrating because Mori is supposed to be such a robust machine. I don't mean to bad mouth them at all, but I would have expected better spindle life out of a machine designed to run 24-7 at high rates. Maybe the technology just doesn't exist yet... who knows?
Good luck to you, and please let me know if you learn about anything concerning these spindles that might help us as well.
Travis
We're in the same boat as you. We had our first spindle analyzed by Mori and they thought the failure was most likely due to a static crash, we couldn't find any evidence to back that up (tried checking alarms, indicated all tombstones to ensure that hadn't been bumped causing any kind of shift, etc.). We will be sending our second spindle in for analysis as well but so far haven't found any evidence to lead us down a path on this one either (had the serivice tech verify that everything was to spec before pulling the spindle and couldn't find any evidence at this point of what would have caused the failure). I'll let you know if we end up finding any definitive evidence on these spindle failures.
A little more background... We bought this machine with the intention of adding it to a pallet pool down the road and 2 weeks ago as we were completing final research on buying a pallet pool and another machine to go with this one (2 machines, 28 pallets) is when the 2nd spindle went out... makes you pause a little before spending a chunk of change on a new system. We have other Mori verticals and lathes and they've always been good machines, we just can't figure out what's going on with this one. We called a couple of the big spindle rebuilders as well as some other shops with NH4000's and couldn't find any definitive evidence that there's a design flaw in the spindle or anything like that (also couldn't find anything to help us understand why we're on our 3rd spindle). We did hear of some other spindles going out without a clear reason why but also heard about a lot of machines that have never had an issue with them. Don't really have a basis to compare this info with a Makino or other similar quality machines as far as spindle failures.
Same boat guys
We have a NH40000 that we had the spindle replaced about a year ago. The service guy that pulled the spindle found a wad of shavings in the cooler line to the spindle that had clogged it up and not let the fluid chill the spindle. We had been doing as you guys were running at max 14000 for months on end 20 hrs a day. The service guy said that the only way that those shavings would have gotten in the line would have been through the machine build.
Here is the kicker a machine shop an hour away bought the same machine with just one serial number from ours and had the same problem and went to court with mori (I believe and they paid for his spindle) and yet we are splitting the cost with the reseller and mori. They dont want to own up to it that it was basicly there problem.
Just out of curiosity...can you tell me what your serial # is?
Travis,Originally Posted by tminnig
Can you answer a few questions...
What is the type of material you are cutting?
The HP of the Spindle?
Cycle time between parts?
size of tooling?
I might be able to provide some insight...
D3Spindles
I would give Dynomax Inc. a call... They are top notch spindle rebuilder.
I have serviced many NH machines and only replaced one spindle it was a 40 tapper 14,000 rpm it had ran at high rpm for a year with no problems. It was replaced do to a crash (lost preload)
Do you warm the spindle up if it has been sitting for more then 24 hours?
sounds like you are trying to machine with some very aggressive depth of cuts
Normal metal cutting should not overload your axis drives
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