Movement of first 2 units

Hi. we have a 4 colour b3 press and it runs ok but when we use all 4 units the image of the first 2 units is moving (like a double image). we've set all the grippers and they are fine but we cant seem to find out the problem. the units have a double impression cylinder (1 for units 1 and 2 and another for units 3 and 4) if that helps????

 

is this press a ryobi 3304?

 

no its a sanxin yk524 similar to a gronhi

 

I don't know about the press that you mentioned but it is normally caused by worn grippers or cam follower, Gripper timings should also be correct.
Check the cam followers and cams.

 

Image Doubling

It cant be traced without knowing the condition of doubling and where it is appearing. As sir A.Kazi said grippers can be the major reason behind it but if u have already done that then check your blanket backings. are they all of correct thickness and condition and it can also be caused by too wavy substrate.
Rgds
Taymour

 

Could you tell me if the doubling is on all sheets or it's one sheet ok and then the other not good...

 

the doubling is every other sheet. there is a double image on the left of a good image then the next sheet its the right of a good image

 

how do you check the cam followers?

 

check them for excessive play or hair cracks.

 

Hi Eltitcho,here some guides which I hope will help you because many factors can cause Doubling in press.
As everyone said try to check - the grippers/cam follower
Improper transfer image blanket/plate - over/under packing-adjust correctly or try to change another blanket (brand) if you can
Is it with thin/thick paper?unstability - run with minimum water
Pressure problems in press -try to verify if pressure is stable between cylinders both sides
Is your press old? -possibility of worn bearings or gears/try to find expertised solutions

Good luck.