Super Precision Turning Machines???

[IntegrexMan]

The problem:

 

I am machining some Medical Grade Titanium and need to produce a bore that has a Ø11.600mm ±.009mm tolerance ...yes millimeters. The part also has some .05mm total tolerance milling features as well. Now the trick is, the process has to have a capability of 1.33 Cpk. For those of you who aren't sure what capability is , I only get about 1/3 of the total tolerance listed above over a 30 piece run. I tried this on our Integrex machines and the thermal expansion of the machines killed me. I only got about a .95 Cpk. So I have been tasked to find a machine capable of this process. I am looking at some super precision turning machines from Hardinge that claim a .005mm total tolerance movement even from a "cold" start . Granted this was done in brass with diamond inserts. I am not so concered about the ability to mill and turn in one machine as I am about obtaining a Cpk for the bore feature. Bar stock size will be about 1".

 

Does anyone have any great ideas?

 

Thanks,

Craig

[Post dept]

The new Nakamura-Tome machines have thermal expansion comp.....

[Watcher]

Take a look at the HARDINGE lathes. They are machines with an outstanding reputation when accuracy talks.

I mean that.

[dolphin1]

check with Mazak as there might be a update for thermal comp.

[Bruce Caulley]

Mazak do a nano-turn machine as well, but it sounds like you need to put the integrex in a controlled environment.

 

Bruce

[Greg Williams]

Okuma Multus B??? perhaps?, They have thermal comp

[JNO]

quote:

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but it sounds like you need to put the integrex in a controlled environment.

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+1000

Your trying to hold .0003 on a .456bore in titanium. Asking a lot in an uncontrolled enviroment.

[Zoober]

:Bold Claim

Miyano will out accuracy any lathe out there. Period.

I have been in more accuracy competitions while an AE for Miyano dealer, than I can count. Miyano beat all, every time - Including the Hardinge Super Precisions.

A lot of these tests were in poorly controlled AZ shops. In one 68 deg. controlled test, the Miyano maintained .002 (metric) tolerance over six hours.

Of course this was all small part turning. Large part turning is much harder to keep from growing.

'Make sure to run machine in metric mode, whatever machine you choose.

 

:End Bold Claim, Flame suit on.....

[YoDoug®]

quote:

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trying to hold .0003 on a .456bore in titanium. Asking a lot in an uncontrolled enviroment.

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We hold .0004 (.312 bore dia) in titanium all day long in our Haas and Kia lathes. However we do keep the shop at 72deg all year long.

[Thee Dragracer1951]

I do a run of .437 bores in A2 in my Daewoo that are .0003 total. I have to make an adjustment every now and then. I just keep an eye on it.

[Guest CNC Apps Guy 1]

Tolerances that close are gonna be a bugger on ANY machine regardless of claims unless the climate is controlled. I'd also look at coolant refrigeration as well.

 

JM2C

[Hymen]

+1 Robert

[Rakesh]

We have Dawoo,Mazak,Goodway,Ameraseiki and two swiss type hardinge lathe. When accuracy and repeatability is concern the Hardinge is the best. If you see my earlier thread, we was looking for supper high precision machines and we narrow down to Hardinge and Nakamura. Than we was very close to buy Hardinge super precision but we bought the 2 nakamura double turret,double spindle c-y axis stuff due to bad reputation of after service from hardinge. Now they improve lot in service call. We had nakamura but the accuracy you looking for,hardinge super precision is the best one.

[IntegrexMan]

Thanks for all the input guys!!! Our shop is a controlled enviroment. The only thing I could add to the machine would be a chiller for the coolant. I'll have to check if they have any other thermal comp stuff for these machines. I know the repeatability and the accuracy of these machines will allow me to hold it, but these machines take so long to warm up and I was chasing the size all day long. I will be looking into all the suggestions you guys gave me. Thanks a bunch.

 

Craig

[Bill Craven]

Hi Craig,

 

Take a look at Moore Precision Tools (http://www.mooretool.com)

 

They build ultra precision machines. A couple of my customers have them.

 

From their website:

 

Linear Axes

• Oil hydrostatic bearings

• Precision linear motor drives

• Precision scales with <1 nm feedback resolution

• ±0.5 µm bi-directional displacement repeatability

• <2 µm straightness full travel

[Rick Henrickson The Boeing Co.]

Iwould think the mazak could do it talk to your dealer and tell them what you are trying to do.

Probably the best lathe would be an index (I think they are german)search for index lathes!

there was a customer in oregon using them and I know they swore bye them.

[Alter Ego]

Our Okuma L370 Captains are better than our Hardinge Super Precision lathes in every respect, including size control. We have [6] of these machines, [4] 2001 and [2] 2005 models, and we are in the tenths all day long. We aim for +/-.0001 and usually are on the money with these machines. Be careful with cutting tool selection on a feature that small because that could have some bearing on your aize control.

[Alter Ego]

Hey Craig

 

How'd you make out with this? Or haven't you taken another whack at it yet?

 

I would like everyone to note that I have not bashed Mazak in this thread where I normally would've back in the "old days"; turning over a new leaf since the accident: live and let suck

 

C

[Hardmill]

quote:

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live and let suck

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ROFLMAO

 

 

PEACE

[Cobra Driver]

If you can find a Seibu actually in the country...that would be the ticket.

[IntegrexMan]

I had the Hardinge rep in yesterday and of course I want them to do a run off for us to prove capability and their ability to make the part complete. I will be at the Mid Atlantic Tool Show next week in King of Prussia, PA next week to see what else is out their. Still keeping our options open. Glad to see the leaf is greener on the other side Chris. Thanks for the replies.

 

Craig

[Alter Ego]

Enjoy the show; hopefully there are some good companies represented there. I would give Okuma, Nakamura-Tome, and Mori Seiki a shot at the deal for sure before I bought a Hardinge; Hardinge service and support are really sketchy in New England but may be much better in your area. One of my beefs with the Hardinge Super Precision lathes we have is that they have no balls at all; the torque limiter system they have [to protect the machine] trips under all kinds of circumstances that leave another machine running [insert chips, decent DOC, normal feeedrate with a big drill, etc] which means increased cycle imes or other limitations that I do not care for.

 

That's my $.36

 

C