Hi all - I'm a new member and this is my first post. (At last there seems to be a useful forum for pressmen.)

Anyway on to our issue...we have a recently installed 626 with perfector. As users will know the sheet brake in the delivery differs from straight presses insofar as the are 3 suction belts (1 in center, 2 at outer edges of sheet). The remaining 4 support wheels have 'star' wheels around the diameter. We have noticed that at most speeds on thin stock (up to 170gm) the incoming sheet occasionally forms a plough shape causing a kink in the sheet which then collides with the previous sheet causing a horseshoe shaped ink mark. We have experimented with the fan settings to no avail. It would appear that the belts are higher than the wheels, thus distorting the shape of the sheet as it descends. I'll get a pic of the mark posted over the weekend.

Any remedies gratefully received.

FYI the issue has now been cleared up and it was so stupidly simple.

Driveside jogger arm in the delivery was not going thru' its full sweep due to the cam arm being slightly off position, therefore the incoming sheet would occasionally be trapped by it causing a midsheet buckle with the resulting intermittent 'horseshoe mark' on the reverse of the sheet.

D'oh!

BTW we now regularly achieve top speed. (14 - 15k iph)