Problem- CROWN VIBRATION

[jw12]

We have a 1998 Crown L1060 and we are getting a vibration when we drill or on a rough bore but it doesn't do it all the time we thought it was our material but it does it on other parts with different material. It vibrates so bad we have to slow feed way down to get to stop and sometimes during drilling it will stop vibrating part way through the part and drill good the rest of the way. We have ran these jobs before multiple times with no problem anyone ever had this problem or know what would cause this.

[Algirdas]

lack of construction and clamp rigidity causes this. what Okuma do you use? is it Lathe or Machining center?

[jw12]

It is a lathe. Do you mean the turret clamping if so how do you fix it

[avtechmachine]

You should first check machine level, about turret clamp you can set the indicator on the turret face then push on it to see any backlash.
Also need to check spindle bearing by set indicator on spindle nose to see any run out or end place, should not be anything.
Next one is X & Z axis gib
Ahn Vuong

[Superman]

You need to narrow your problem field down,
sounding like a problem on the Z-axis
( I assume basic checks already done, like drill is on c-line, turret does clamp-and has no play[ loose bolts etc.])

-is the problem occuring when turning OD going Z-, or Z+( back turning) facing in to centre, or just on internal Z- direction, do sizes change form part to part.

If just on the Z-axis,
- turn machine OFF
- mount dial indicator on chuck, dial against turret face
- can the Z-axis rotate or slide without moving the turret.
- if yes, you found the problem area( check right thru, from the actual motor drive and drive key, to the bearings and thrust bearings at the other end)( don't forget to check the lub supply)
- leave the leadscrew nut to last ( maybe the ball-bearings are worn and need replacing-a little more experience needed here )

same procedure for X

[CarsonD]

Just as a long shot that sounds a lot to me like bar rattle.

That will happen when your running bar stock. Sometimes your bar can be a little to long, bent, or the collet pressure to low.