[witbike]

Hello guys,
I have a problem with tailstock in my Hyundai machine on Siemens 840C. When I move on tailstock (M11 M31) it back when should press on part... You know, it move on, touch the part and slow move back. It look like somethink is wronng. Are there some elektromagnet which hold it?

[OkumaWiz]

Is your tailstock pressure too high and the body is being moved after contact with the part?

Or is body stationary and quill retracts?

[witbike]

Pressure not to high because tail slow move on to the part. Body is being back when tail press on the part.

[atmosports]

Tailstock being used manually or automatic should have the body move forward onto the stop(Using switch or M11), then the tailstock quill should be extended into the part(Using switch or m31). It should then stay in place until removed manually with the switch or else with M32(Sleeve backwards) & then M10(Body backwards). If it is slowly slipping back one of the tailstock body clamping cylinder's is not clamping correct, I believe you can pull them out & rekit them with new seals etc. I have not had this problem but have had the opposite where they cylinder was seized with the tailstock in the fully retracted position, spraying with some penetrating oil & a tap on the top of the cylinder seemed to free them up. I think there may be a stud running though the cylinder that may also need tightening. I'm away from the shop for a few days so sorry can't have a look at ours to jog my memory or look in the manuals either to see what the part's diagram/listing shows