Print Swerving - Shifting On Line - HP Latex 335

[J4cko]

Hi Guys,
Hope you can help or offer some advice please

A couple of times today, and once during the week, we had the print almost swerve off its path
Our prints have an equal gutter on each side of the print

The roll remains straight, it is not unwound uneven, but for some reason the print seems to be drifting off course

Almost in steps
like a small swerve, before resuming a straighht line on a new path
and then the same again

If you see the attached images

The result, was that what was a 2cm gutter on each side, had become almost 4cm on one side, and 0.5cm on the other side, after several metres of printing

Any suggestions what may be causing this ?
Its only on one of our 5 machines
Ive tried to show it in a diagram, and also a couple of shots that show how it swerves and drifts

Any help greatly appreciated

thanks a lot
Jack

 

[balstestrat]

Clean encoder from end to end.

 

[J4cko]

Thanks Balststrat, i will do that 1st thing in the morning.
Were the symptoms i showed a common issue if the encoder strip is dirty ?

I wondered if it was because i had cut prints mid roll, but i do that all the time and am always careful not to apply pressure to the roll

Any other things to try or check ?
I havent seen this in years of using the HP latex, altthough this machines has been worked hard the last couple of weeks, as we had 2 machines out of production

Any other advice appreciated too, thank you very much

 

[balstestrat]

Well it's either the roll moving sideways, not likely like that. Or it's the carriage position jumping and encoder is the first thing to check.

 

[J4cko]

Thank you very much
I went back to my warehouse
Cleaned the strip
Cleaned and lunricated the rail
And popped a few prints on
Fingers crossed
Will see in the morning
Thank you

 

[J4cko]

Thank you, solved the problem, much appreciated Balsetstrat