[EPTech]

Hi guys,

Because of a broken line in the central lubrication system, the ball screw on the X axis has been without lube for a while. I do not know exactly how long but I noticed it because the X movement has become more noisy over the last week. There seems to be no damage because the axis is easily moved by hand. I repaired the line but there is still no lube coming through. The return flow valve is in the right direction though. I suspect the line has clogged during the dry time.
Does someone know a way to de-clog the line without the need to take apart my machine? Is there an agent that dissolves the greasy oil in the line without damaging the ball screw?
The ball screw will become more quiet when it is lubed properly right?

[Aaron liang]

The oil distributor may be bad.
You can manually oiled the ball screw.Then turn the ball screw after a period of time to check the sound.
Ball screw with noise.Not rule out the ball is damaged.

[EPTech]

Thanks for your input Aaron,

The oiler still generates enough pressure (50 psi peak then drops to 35). It stays under pressure for quite some time until the next charge. Before I repaired the broken line, it just dropped instantly. I took the line of the X ball screw and hooked up a manual lube pump with a hose and lubed the ball screw that way but the noise never went away. Finally I put it back on the circuit and decided to use the machine as is. The machine is still precise and the servo diagnostics does not show an increased current but I will monitor it from time to time. I am hoping the machine will serve me for another 3 years. It is a leadwell VMC-25 from 1995.

Anyway, thanks again for your input.

[Aaron liang]

You are welcome.
Noise on the case of less precision is not affected.Long period of time may be some problems.
Maintenance of these old machines and more life to be extended.
Good luck.

[EPTech]

The oil line that goes to the X-axis ball screw was broken and I fixed this. In taking apart the X-axis assembly I found that the noise is coming from the double sided angular bearings that sit in the arbor that holds the screw itself. I suspect the cause to be sped up wear due to bad adjustment of the coupling between the lead screw's shaft and the servo. Does anybody know whether these bearings are press fitted? The bearings are about 150$ a set and if they are easily replaced, I will give it a shot.

[Aaron liang]

I repaired leadwell machinces,bearing are NSK's
Bearing installation,the same of the combination of old bearing.
Bearing end caps need to preload 0.03 ~ 0.05mm.