Risograph MH9350 Skew between positions 1 and 2

[richsouth]

Hi there,

Apologies if this issue has been asked and solved before but I couldn't find any references after searching here.

Long story short we've recently had 2 new Riso MH9350s delivered and I cant get the 2 drum positions perfectly aligned..... I know this is Risography and that can be expected but this skew is consistent. the prints start off in line but the second drum position eventually drifts so its around 1.5mm higher at the far end of the paper. Has anyone experienced this before? my the engineer where we bought them seems to think this is pretty normal, and usually i would agree but its so consistently wrong there must be away of aligning the two positions.

Thanks in advance

R

[20gaugeO/U]

Are these machines NEW? or new to you???

If you are talking Registration:
You can adjust each drums master making write start position. You'll have to burn masters for each drum and measure, more than likely just one of them will need to be adjusted to find a happy medium. Even if you get them "perfectly" lined up on top of each other there is still a +/- tolerance of a couple mm. Usually running the machine faster makes the image jump around a bit more, combine that with poorly cut paper and your image can jump around even more.
It's a friction feed system running at 150 ppm, it will be allowed a tolerance


If you are talking a true SKEW:
Look into replacing the impression roller and possible checking the parallelism of the carriage that holds it. Or possibly the squeegee roller inside the drum is out of balance (fun to mess with) making the master slide on the drum. At least with 2 drums you can more their positions around and troubleshoot like mad.

Just my 2 cents