Length variation in Cut to length line

[eshan3012]

I am facing length variation problem in my Cut to length line,In my line there is a feed roll which is having servo motor with kinetix 7000 servo drive (allen breadly) & there is an auxiliary non contact measuring device Beta laser.
when i am running line with support of my auxiliary device then there is length variation due to jerk found in feed roll when shear cut sheet, but when i am running line through feed roll then there is no length variation but accuracy of line is not stable, i checked laser feedback there is no problem in laser unit

 

[James Mcquade]

Welcome to the forum.

Before the sheer cut, is the length correct and stable?
If it is, can you place a clamp on the system before you do the sheer cut?

What type of sheer is it? a slant cut or straight cut?

james

 

[eshan3012]

Its a straight sheer,
when sheer cut the sheet actual length shows in HMI & variation shows in screen whenever there is error in actual & desired length of sheet.
what type of clamp i have to connect in system, please suggest.