Lathe Bored jaws running out

[DavidB]

On our new machine we can not get bored soft jaws to run any better than .0015".

We have tried everything even a new chuck (4.5k later).

We have tried different chuck pressures and we use a bung in the back with the jaws closed when we are boring them.

 

At the moment I'm

 

Any ideas?

 

Thanks

[crazy^millman]

Have you checked the mounting ring on the spindle and seen if it is running true?? If the spindle liner got warped, or the bearings are shot on the spindle no matter what you do new jaws, new chuck you will still get the out of round condition. I would start investigating spindle, and mounting conditions at this point.

 

HTH

[DavidB]

Today I check the tapered ring that locates the chuck and its with in 0.0004mm. I think its bearings but the machine is only 14 months old?

 

Mazak will be here tomorrow to investigate.

 

 

Wish we bought an Okuma

[chris m]

Even if the chuck itself was running out you should still get considerably better results than you're seeing. It sounds like you are doing everything right; how are you confirming that the jaws run out that far? If you're gripped on a solid piece that you know is round and you're still seeing that much indicator movement with a new chuck you may have a spindle problem, as Ron said. If I couldn't get better than .0005" on a newly bored set of jaws I'd be in serious trouble; sounds like you are, too.

[Dave Macdac Engineering Inc]

“I think its bearings but the machine is only 14 months old?”

 

I had a mill once that was only 6 months old but every part that came off it was out of tolerance; especially any thing curved. No one believed that it was the machine, until it happened to the owner one day. Mori came by and said it was a faulty bearing and fixed the thing for free but it does happen even on new machines.

[Kevangel]

I bought a new manual lathe when I started my shop and after one year it was turning out of round .001 in. I adjusted the tapered roller bearings on the spindle and it has been perfect ever since. just my experiance. Saw this at shops I had worked at (chatter and out of round at another) and co-workers said lathes were junk...they needed a one hour tune-up..

[DavidB]

Chris,

We are using a ground rod to in the bored soft jaws to check run out.

 

I'll let you know what happens today.

 

Thanks

[Tim Simmermon]

We just had the smae problem, but it was on a 15 year old Ikegai, with a 15 year old chuck. Replaced the chuck and all is well. We do believe that the bearing spindles are soon to follow. You can definitely hear the difference now. If you have 2 of the same machine, you might want to compare how they sound when running at the smae RPM.

[DavidB]

Tim its a new Mazak Integrex we only have the one.

Our 15 year old Okumas run within 0.0005mm

[Greg Williams]

quote:

---

Wish we bought an Okuma

---

[DavidB]

Greg, Maybe I should have said "I wish Okuma would sell us a machine"

 

[Mick]

LOL.. Hmm... We have a Multus B400W arriving just before Easter

 

We're all looking forward to it

[Mr. M]

We had this problem on our new Mazak lathe, turned out the locating ring on the kitigawa chuck was running out.

 

I just found out my Integrex is being sold and I'm getting a Multus!

[Guest SAIPEM]

I would be certain to check B-Axis alignment for the tool holder.

[Mr. M]

????

[ktd]

Have you tried using a proper adjustable chucking ring to bore your jaws. Royal I believe makes them.

[Guest SAIPEM]

Ben,

 

The orientation of the spindle axis is controlled by address B.

Problems with the B-Axis rotation & indexing can cause the problems Dave is having.

[FAS]

Don't use a plug and see if you get the same results. Chuck on a plug and trepan a face groove on the front of the jaws, use a ring in the face groove to then chuck on and bore the diameter thru. Just a thought.