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Problem with simultanious machining on multitasking machines

Alphington

Plastic
Joined
Nov 22, 2017
We have recently taken delivery of a new Multitasking turnmill machine. I don't wish to name the manufacturer so I will just say that our machine is in the same category as Mazak I series, DMG MORI NTX, etc. Two spindle, left and right with milling head and lower turret.

During testing after installation we discovered a problem, and I would like some input from others as to whether this is a common problem or our machine has a serious fault.

When turning a finish cut on the left hand spindle (main Spindle) using the lower turret, we send the milling head for a tool change. We are getting a change in the machined diameter of 0.015mm caused by a combination of the milling head moving and the action of the tool changer. i.e. we have a raised ring on the turned diameter. If we mount a dial indicator in the left hand chuck and place the finger on the turret, then we move the milling head from extreme left to extreme right we see a change of 0.009mm on the dial. If we place a machine level on the turret and move the milling head from extreme left to extreme right we see a change in the level of the turret 0.024/1000. The machine manufacturer sent his installation team back an re-installed the machine a second time with the inclusion of 8 anchors into the concrete foundation to further stabilize the machine. The problem was not improved in the slightest. The machine foundation is new and substantial. So my question for operators of this type of machine is: Is it normal to see the accuracy of parts machined by the turret influenced by the movement of the milling head?
 
I can't tell you what the problem is. But I would not accept that much error on a new 'Multus U'. I have no idea what tech support is like in Vietnam. But if it were here, the veins in my forehead would be blowing out, while I was yelling at whoever did the install. At installation they need to qualify the machine accuracy to their own specifications, and .015mm is NOT within *Okuma Americas specs. There is a lot of weight involved in a machine that has that much going on, but it is irrelevant when they specify that on delivery the machine is ^^^^ good.

* I have no idea what Okuma Asia is like.

R
 
Something is moving and is seriously wrong.

Might be something loose or maybe something cracked.

Machines of this type are often difficult to get properly aligned on all of the axis but you should not see the turret level change just because the milling head moves.
 
During the original installation I could see that the guys doing the install were starting to pull their hair out, when I investigated the numbers that they were recording it was obvious that something was unstable about the machine. It took them 8 days for 3 guys to get the machine to pass the post install tests. The problem was that the post install tests are all done with the milling head in a fixed position in the Z. I insisted on them doing further tests moving the milling head and sure enough the machine was unstable. They then did a complete new install with inclusion of 8 anchors but no change, still unstable. We are getting support direct from Japan. I just needed to confirm with others that this is far from right before I got down to some serious letter writing.
 
....I will just say that our machine is in the same category as Mazak I series, DMG MORI NTX, etc. Two spindle, left and right with milling head and lower turret.

Same category or class? Same category of machine could include some low end builders where odd behavior might not be unusual. Same class of machine would only mean high end top quality builders where behavior as described would not be expected or the norm.
 
Same category or class? Same category of machine could include some low end builders where odd behavior might not be unusual. Same class of machine would only mean high end top quality builders where behavior as described would not be expected or the norm.

Same class, and definitely in the top 3 made in Japan, not, "made for Japan". You will understand that given that this is a problem in progress I cannot and should not name the manufacturer.
 
Same class, and definitely in the top 3 made in Japan, not, "made for Japan". You will understand that given that this is a problem in progress I cannot and should not name the manufacturer.

That is very proper and ethical on your part. Good to see a customer behave this way.
 
That is very proper and ethical on your part. Good to see a customer behave this way.

Thanks, I am a big believer that you should treat your supplier in the same manner that you would like your customer to treat you.
 
You say substantial foundation, but is it actually in spec with the machines manual stated requirements. Because if the machine is properly anchored down and its still moving, then you have to question to what is it anchored and is that doing all it should? Not saying you got it wrong, but how certain are you its right did you do quality control on what the subcontractor who laid the foundation to ensure it really is right? Because again no disrespect, but you would not be the fist person out there to have a subcontractor skimp on a foundation!
 
The machine foundation is new and substantial.

How new?

Concrete takes time to cure. I have seen first hand problems arising from the machine being installed too soon after the foundation was poured. A few years ago we bought a new large gantry mill. Despite knowing it's arrival date 6 months in advance our managing director decided to ignore my many protestations and wait until a month before it was due to be installed to dig and pour the foundation. Then the useless excuse for a contractor used a very wet mix, didn't layer the rebar properly or even properly level the surface. The whole thing was half-arsed and I was incensed. The installers from the MTB were not happy either, complaining about the concrete being "spongy" and having serious trouble levelling and aligning the machine. They had to come back six months down the line when it was actually ready and redo it. It's been fine ever since but the whole mess could easily have been avoided.
 
We have recently taken delivery of a new Multitasking turnmill machine. I don't wish to name the manufacturer so I will just say that our machine is in the same category as Mazak I series, DMG MORI NTX, etc. Two spindle, left and right with milling head and lower turret.

During testing after installation we discovered a problem, and I would like some input from others as to whether this is a common problem or our machine has a serious fault.

When turning a finish cut on the left hand spindle (main Spindle) using the lower turret, we send the milling head for a tool change. We are getting a change in the machined diameter of 0.015mm caused by a combination of the milling head moving and the action of the tool changer. i.e. we have a raised ring on the turned diameter. If we mount a dial indicator in the left hand chuck and place the finger on the turret, then we move the milling head from extreme left to extreme right we see a change of 0.009mm on the dial. If we place a machine level on the turret and move the milling head from extreme left to extreme right we see a change in the level of the turret 0.024/1000. The machine manufacturer sent his installation team back an re-installed the machine a second time with the inclusion of 8 anchors into the concrete foundation to further stabilize the machine. The problem was not improved in the slightest. The machine foundation is new and substantial. So my question for operators of this type of machine is: Is it normal to see the accuracy of parts machined by the turret influenced by the movement of the milling head?

Something is definitely wrong.

Under The Covers Of The Mazak - YouTube

^^^For a bit of integrex "Style" sanity check, check out Peter's youtube video where he adjusts and tightens a few things on his B axis. Machine has a lot of it's covers/way covers off. Nice to see. Check out his use of gauging bar in mill head spindle. (But no lower turret).

Peter's machine is an older style, but the newer integrex (and perhaps smaller) have a very accurate B-axis rotational movement of the head of the order of 2 arc seconds. That's actually one of the most accurate movements of all the machines MAZAK make (just about. Ball bar tests of an integrex for movement of milling head (for example a circle in the ZY plane same as XY plane on conventional vertical mill) is of the order of 3 micron, whereas a more regular but GOOD vertical mill will test out at about 5 micron circularity. Part of the reason for that is the machine only has to travel about 10" in Y max.

So you have a change in level 24 micron in one meter? (when the "Mill" is moved from here to there?). And also 9 micron "Difference" as measured from and between spindle to lower turret when mill assembly is moved from one end to the other ... (Need to do some math on this just to check to check this is not a "Trick" question kind of thing (back in a while lol)).



Even something like a DMG Mori short bed two axis very precise lathe will have wide tolerance band of 40 micron (straightness) over 1000 mm (1 meter) when the simple two axis lathe turret is moved back and fourth, but actually tests out around 18 micron / meter or better (even though it might have a 500 mm Z travel etc. but the idea that the position of mill head along the Z axis screws up the relative position between left hand spindle and lower turret is a different kettle of fish. But do keep in mind combined errors that are natural to any machine when you get this all "Ironed out".

Some guesses:

1. Machine is rocking across a diagonal pair of "legs" /feet when mill assembly is moved from one end to the other. This "Rocking" action may be imperceptible but the feet may be unevenly loaded, causing a sort of "Flexing" action in the frame/bed casting between turret and spindle? . On some DMG mori B axis mill turn machines, this would be nearly impossible as the machine has three legs / feet lol. Guessing MAZAK machine here with lots of feet and a long bed / Z travel.

2. Maybe the machine has been improperly stored for a very long time and has a "twist" in the casting/frame?

--> (I wish feet had electronic strain gauges in them so you would know exactly how the machine weight is distributed, especially over time as a new foundation will settle and move).


Some Questions:


1. What province are you located in Vietnam?

2. Do you have to bribe a lot of local officials just to get equipment and machines into the country ? Can equipment just be sitting on a dock for a really long time?

3. Personally I'm not very taken with the lower turret "Concept" on the Integrex style machines, and don't have any experience of running a mill turn with lower turret... BUT those are supposed to be able to perform "pinch style" operations on shafts for improved dimensional accuracy (theoretically). But also wonder if there is best practice of parking the mill head in a set of consistent locations while using the lower turret ? Which kinda destroys the ultra multi tasking selling point, right ? I have to admit I am skeptical of the whole lower turret and mill head working together kind of thing but Integrex can be a super platform. I remember you mentioned in another thread starter the issue of tool changes whilst turning using the lower turret.

4. How many feet does your machine have and in what kind of layout?

5. How much does your machine weigh/mass of machine ?

5.5 Chuck size and thru bore/kind of turning spindle ?

6. Rough maximum Z travel (Approximately)?

7. Do you have the inspection certificate for the machine? [As built before it left the factory]. To eliminate factory build error.

8. Have the installation guys noticed any weird "creaking" noises in the bed casting as the mill moves up and down the bed?

9. Is the indicated distance between spindle and turret at a max or minimum distance when the mill head is "parked" for a tool change? (My hunch would be that it would be at maximum out of tolerance distance at the tool change if feet are not loaded correctly; loading frame at that position opens up that distance between turret and spindle? You didn't state +ve or -ve change or how it maps out? ... Just going with the idea that the mill head will have the least influence on the turret and spindle distance when positioned at the far end of the machine i.e. at the right hand side, and the most influence when almost directly across the left spindle and lower turret ? (Maybe) ? ).

10. What orientation is your level in for the turret? Z orientation or Y? turret pitches up and down along Z axis..? Or Yaw; tool goes high and low? Are you able to orient the level "Flat" with respect to ground plane/gravity on turret diagonally pointing to mill tool change position (while mill head is in tool change position)? [You might need cobble together a "Gizmo/fixture" for that].

11. Do you have any plans for metrologists to come in and generate interferometer plots and ball bar tests for your machine? [Proper inspection and mapping of machine; if so you might find how "straight" the machine is versus how it might be "warping" from insufficient leveling.] Might take the guess work out of what's really going on? Or maybe something IS loose and everything else is fine?

12. How many "Integrex style" machines has the installation crew installed before? And have they installed the particular model of machine you have before?

One Comment:

IF moving the milling head and assembly caused such a major performance "Fail" (in general)of the lower turret it would be splattered all over PM forum and the machine would be kinda of "black balled" for that particular failure... So the fact that that specific problem is not common knowledge I would say or "indicate" that there is something wrong with your specific machine... Like what folks are saying here. Foundation not right, or machine twisted from transportation damage or long term bad storage twisting the bed (maybe) or something just loose... not tightened down or build error that factory inspection did not pick up on? [Need to do a bit of "Sanity" math on the measurements you have thrown out there to double check how bad things really are or not].






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Something the MAZAK guys impressed on me regarding Integrex is that it is really a mill that happens to do turning... rather than a Lathe that has a mill strapped onto it. And they then try to stress that mills typically are built to much higher quality than lathes (maybe for MAZAK perhaps, not sure about the scope on that statement in regard to other Machine tool builders etc. ). Make of that what you will :-)
 
3. Personally I'm not very taken with the lower turret "Concept" on the Integrex style machines, and don't have any experience of running a mill turn with lower turret... BUT those are supposed to be able to perform "pinch style" operations on shafts for improved dimensional accuracy (theoretically). But also wonder if there is best practice of parking the mill head in a set of consistent locations while using the lower turret ? Which kinda destroys the ultra multi tasking selling point, right ? I have to admit I am skeptical of the whole lower turret and mill head working together kind of thing but Integrex can be a super platform. I remember you mentioned in another thread starter the issue of tool changes whilst turning using the lower turret.

IT's just one of those things that you really need to know you have the right parts for the machine.

The lower Turret is sold as the second op function primarily. So doing as much work as possible on the Main, handing it off, then ideally not doing any Milling on the Sub (or minimal), while the B is working on the Main. The way the B is oriented to work on the Main is generally 225º off zero, so pretty much out of the way for work, and 180º for a tool change.

R
 
You say substantial foundation, but is it actually in spec with the machines manual stated requirements. Because if the machine is properly anchored down and its still moving, then you have to question to what is it anchored and is that doing all it should? Not saying you got it wrong, but how certain are you its right did you do quality control on what the subcontractor who laid the foundation to ensure it really is right? Because again no disrespect, but you would not be the fist person out there to have a subcontractor skimp on a foundation!

The machine manufacturer inspected our foundation drawings before we ordered the machine and it is written into our contract that they agree that the foundation is suitable. I personally inspected the excavation, compacting of the base metal, preparation and setting up of the rebar and pouring and vibration of the foundation itself. I took samples of the concrete during laying and had them laboratory tested before we ordered the machine. The machine supplier look measurements between the machine and the outer edge of the foundation using micron dial indicators during dynamic testing of the machine. The machine supplier makes no claim that the foundation is insufficient in any way. On Friday just passed we formally informed the machine manufacturer that we are rejecting the machine and have requested it's removal from our factory. HQ Japan has now ordered an internal investigation and placed high priority on it's management to find a solution to our problem. Any manufacturer can have a problem, we are about to find out how this one performs when it has one. Fingers crossed I have chosen the right manufacturer.
 
IT's just one of those things that you really need to know you have the right parts for the machine.

The lower Turret is sold as the second op function primarily. So doing as much work as possible on the Main, handing it off, then ideally not doing any Milling on the Sub (or minimal), while the B is working on the Main. The way the B is oriented to work on the Main is generally 225º off zero, so pretty much out of the way for work, and 180º for a tool change.

R

That is not quite correct, the turret is NOT sold as a second opps function. The turret is sold to provide the ability to perform "simultaneous machining on both spindles." and, "to provide efficient machining of simpler parts". Read the manufacturers marketing info, I have, for every brand of machine in this class. The tool change time on the turret is 30 times faster than the milling head. A machine fitted with a turret blows the doors of a machine that is milling head only.
 
Sorry? Multus U is sold as a second op function. If it weren't, there would be no reason to buy all that machine. Having a 2 axis Lathe and 3 axis Mill side by side would do the job faster as you pointed out.

I have run Integrex, Multus, Multus U, MU and NZ machines. There are cheaper ways to do it, there is a specific reason they are set-up that way. Of course it would be simultaneous doing the Milling on the Main and the second op on the sub (or vise-versa) but working at the same time.

If the course is doing simple Turned parts, then you got the wrong machine.
 
The machine manufacturer inspected our foundation drawings before we ordered the machine and it is written into our contract that they agree that the foundation is suitable. I personally inspected the excavation, compacting of the base metal, preparation and setting up of the rebar and pouring and vibration of the foundation itself. I took samples of the concrete during laying and had them laboratory tested before we ordered the machine. The machine supplier look measurements between the machine and the outer edge of the foundation using micron dial indicators during dynamic testing of the machine. The machine supplier makes no claim that the foundation is insufficient in any way. On Friday just passed we formally informed the machine manufacturer that we are rejecting the machine and have requested it's removal from our factory. HQ Japan has now ordered an internal investigation and placed high priority on it's management to find a solution to our problem. Any manufacturer can have a problem, we are about to find out how this one performs when it has one. Fingers crossed I have chosen the right manufacturer.


It's nice you have HQ Japan of "Mystery builder"... handling that for you.

Even a smallish I-200 weighs about 28,000 lbs (60" between centers).

On other recent forum threads I do kinda agree with mentality of getting a special / thick concrete base poured to the specifications of the manufacturer (WILIE was mentioning that); I'm of the opinion if the base/concrete pad is not 100% correct to Machine tool builder's requirements then if you are looking for BEST precision and accuracy of the machine and the machine does not deliver that performance then the MTB/vendor can say "Oh well you only have a 4" or 6 " base and walk away.

Long story short (from the info provided ) I would guess or at least investigate the possibility of a pad or "Foot" in the top LEFT hand quadrant (in plan), (as you normally stand at the machine) that may be "floating"/ not loaded correctly so when the travelling column assembly moves to position for a tool change that floating quadrant is partially bent or flexed down-wards to meet the floor ( become more fully loaded) I.e. it may look like it's contacting the floor but might be shy of 3000lbs or more of reaction force from the floor/ jack / pad?. That flexion by unsupported weight causes the spindle to move away from the turret (diagonal twist or flexion) across a diagonal loaded pair of feet that is more central to the machine. In other words the bottom left hand quadrant of the whole machine is supported well but the TOP-LEFT hand quadrant is not? 3000- 4000 lb downward force laterally across an unsupported part of the casting, could that cause a 9 micron movement/flexion and separation of turret and spindle. (+ additional partially unsupported load of travelling column and mill head assembly, another 4000 lbs of weight / downward thrust?) ?

Without seeing video its bit of an elaborate guess.

Alphington writes :

"HQ Japan has now ordered an internal investigation and placed high priority on it's management to find a solution to our problem. Any manufacturer can have a problem, we are about to find out how this one performs when it has one. Fingers crossed I have chosen the right manufacturer".



I totally agree the test or "Mettle" of firm is determined not when things go 100% correctly but when stuff goes wrong and what they are going to do about it (kind of thing) OKUMA are really good for that.

Sometimes in the USA one has to have realistic expectations as to what a particular vendor and MTB is able to provide and try to fairly anticipate any predictable short falls in advance without having to bridge too many unrealistic gaps given that you may be paying major "bucks" /$ for something.

In Vietnam, having been out there for rather "Complicated" things 15 years ago I can only imagine what one would have to go through to get this 100% sorted.

BTW @ Alphington your English is excellent! Are you a Vietnamese national or are you a foreign national to Vietnam working for a foreign company or some combination thereof? Twisted frame? Build error or storage and shipping problem? Installation error? I have to admit there is an art to leveling any machine that is long, heavy and has many feet/pads...

Cheers,
 
Sorry? Multus U is sold as a second op function. If it weren't, there would be no reason to buy all that machine. Having a 2 axis Lathe and 3 axis Mill side by side would do the job faster as you pointed out.

I have run Integrex, Multus, Multus U, MU and NZ machines. There are cheaper ways to do it, there is a specific reason they are set-up that way. Of course it would be simultaneous doing the Milling on the Main and the second op on the sub (or vise-versa) but working at the same time.

If the course is doing simple Turned parts, then you got the wrong machine.

The milling head alone can perform 2nd ops on the 2nd spindle, milling or turning without the turret right? So the turret is not required for 2nd ops, it is required for simultaneous opps. I have taken your term "2nd opps" to mean secondary operations, being operations that happens later. Perhaps we have some confusion over terms? Where I said " simple parts" I meant to say simple turning operations. My point is, that if the turret cannot be used simultaneously with the milling head working on the other spindle then the machine fails in it's intended purpose. I submit that one cannot expect to perform high precision turning in one spindle while rough milling simultaneously on the other. My initial question was, should I expect to be able to run a finish cut using the turret on the left spindle while performing a tool change on the milling head? What I do know for sure is this, I can take a finish cut on the RIGHT spindle and simultaneously change the tool in the milling head with ZERO effect on the turret turned finish/accuracy. I would have expected that the right spindle would be more susceptible to deviations given that it is not a fixed component, however the opposite is true in my case.
 
Cameraman, I am an Australian, I moved my company here 6 years ago. Vietnam has come a long way in 15 years while many other countries have been moving more backward that forward. Vietnam treats it's manufacturers as a truly important and necessary part of it's economy and does everything it can to support us. A massive improvement over where I came from. Our machine foundation is substantial, the manufacturer is bound by our contract to have ascertained the suitability of the foundation prior to signing the contract. I have the first of this type of machine to be sold into Vietnam, I managed to get clauses added that leave me very well protected. They can't walk away, unless they hand back all of my cash and they are prepared to sacrifice the machine's reputation in Vietnam, the fastest growing market in Asia. The extra anchors were added ensure that the machine has each pad loaded, or else the anchors would pull the machine out of shape and it would fail the factory tests. Prior to adding the extra anchors, they tried increasing the load on various pads to stop the twisting,the problem is that by the time they have made enough change to reduce the twisting, the entire machine is all out of spec. I suggested to them that the machine was perhaps aligned in the factory with incorrect loading on the pads, and that when the machine is now correctly loaded that it is then out of alignment, and thus, when it is in alignment it is incorrectly loaded, and that there is no happy medium. You can imagine that my suggestion did not go down that well with the engineers at Japan HQ, so we agreed to a second attempt at the installation with added anchors and we are back to the start. I think that we are about to see a fairly in depth investigation, I just hope it doesn't take too long.
 
Sounds like you did an excellent job of pre-purchase due diligence, well done for that. That's quite the adventure, going from Oz to Vietnam, at least to this sheltered North American. If you have a moment, an "OT" posting of your experiences in the country and working with the government and employees would be welcome, I'm sure it would open a lot of eyes here.
 
Going out on a limb...

Having actually adopted a child/infant from Vietnam (15 years ago ) the one thing that I learnt very quickly as a Brit/European American is that nothing and I mean nothing happens without "Appropriate" bribes to local government officials... And many others.

so:


1. We have not established whether "Alphington" is or is not a government official (in spite of having sound/ reasonably sound engineering knowledge). OK I found out too late he is a legit ozzy :-)

2. Bear in mind Vietnam IS and I mean really IS a communist county, but has the capability to achieve great and wonderful things but the achievements of Ho Chi Minh are sung by school children every day at school etc.

Ho Chi Minh - Wikipedia


So with phrases like,

"Any manufacturer can have a problem, we are about to find out how this one performs when it has one. Fingers crossed I have chosen the right manufacturer. ".

"I meant to say simple turning operations. My point is, that if the turret cannot be used simultaneously with the milling head working on the other spindle then the machine fails in it's intended purpose"



"I submit that one cannot expect to perform high precision turning in one spindle while rough milling simultaneously on the other... "

"the turret is NOT sold as a second opps function. The turret is sold to provide the ability to perform "simultaneous machining on both spindles." and, "to provide efficient machining of simpler parts". Read the manufacturers marketing info, I have, for every brand of machine in this class. The tool change time on the turret is 30 times faster than the milling head. A machine fitted with a turret blows the doors of a machine that is milling head only. "

"The machine manufacturer inspected our foundation drawings before we ordered the machine and it is written into our contract that they agree that the foundation is suitable. "

^^^that one is quite "Fishy" from a number of different angles.

"
I took samples of the concrete during laying and had them laboratory tested before we ordered the machine. "

^^^ Even more spurious and " Fishy "... "Laboratory tested"... I'd like to see those lol.

"The machine supplier look measurements between the machine and the outer edge of the foundation using micron dial indicators during dynamic testing of the machine. "

^^^Even more bizarre but interesting.

"The machine supplier makes no claim that the foundation is insufficient in any way. "

" On Friday just passed we formally informed the machine manufacturer that we are rejecting the machine and have requested it's removal from our factory"...

"Fingers crossed I have chosen the right manufacturer."

...

OK Looks like the machine may be deliberately sabotaged so that OP (possibly) or OP's associates can score a bribe to "Fix" the problem.

Turns of phrase like " I submit..." , "fails in it's intended purpose...", "provide the ability to perform "... "Claim" ... "that the foundation is insufficient in any way"

^^^ These are all legal turns of phrase and very specific language that also pertain to intellectual property / prosecution of IP.

"
Any manufacturer can have a problem[/U], we are about to find out how this one performs when it has one. Fingers crossed I have chosen the right manufacturer. ".

^^^ This, you'll have to forgive me but it really sounds like in Vietnamese business terms "code for"... I hope these machine tool builders understand that Vietnam largely runs on birbes and correct bribes of directors of companies and government officals and other organizations, and unless they get "with" the Birbes... The machine will be sent back as per contract as there seems to be a mysterious "Unexplained" problem with "Said" machine that could be "Fixed" with the right mechanisms of bribery to make things happen. "Finger's crossed" I hope (for their sake) they know how to play ball in Vietnam, otherwise we have found the wrong company to work with.

Forgive me if I am 100% wrong on this but (from my experience) this is how it sounds.

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But on the other hand you say you are are Australian so you must be 100% legit :-) I'm just razzing you a bit as Vietnam is very difficult unless you "play the game"

Cheers...

 








 
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