Printheads scraping paper on HP Z6100

[jonkovach]

Has anyone ever seen printheads actually scrape the paper as they pass back and forth? It doesn't happen a lot, and it's not necessarily on heavy ink areas, or anything like that. It will print fine for 15-20 feet of paper, then all of a sudden, the heads start scraping the paper.... screws up tons of prints. I can fix the problem if I am here - I can tug down hard on both sides of the paper and it flattens back out. The paper seems to cockle up, sort of creaing a small wave, and that is where the heads scrape. I feel like it gets buckled as it's being fed in.... it's fine for a while, but then it starts to bunch up on itself......

Also, I have reduced the humidity in the room, and really (REALLY) started to control that. I'm at about 72-74 degrees, 39-43% humidity). That seems to have helped, but did not relieve me of this problem.

Any ideas? I can take more photos if it would help.

Thanks,
Jon

Edited by: Jon Kovach on Jun 12, 2008 5:44 PM

[sgirard]

Do the Zs have a platten gap? If so you could try raising it. Might need to make new profiles though.

[seejay]

NOt familiar with this model, but on an older model, there used to be 'daisy wheels' that kept the paper on track. occasionally, a cack-handed operator (technical term for numpty) would pop them off when feeding paper. This in turn, caused a similar problem to what you have.

seejay

[Patcbx]

We had a similar problem with our HP5500. The vacuum under the platen would quit working and wreak havoc on our prints. tech support suggested a firmware upgrade--which we received and installed today. don't know if that is the answer yet, but it is something for you to check.

Pat Peterson
Color-Box

[jonkovach]

Well, I tried cleaning the rollers, and it didn't help. I don't know how to raise/lower the platen - but along those lines I increased the vacuum pressure to what I believe to be the strongest possible, and that helped a little, though it did not resolve the issue. I don't know where the daisy wheels would be.... any ideas on that? There are small black wheels right where the paper comes out, but they look fine. None of them are broken - one popped off once, and I put it back on, but it doesn't look like that's causing any problems. My firmware is completely updated. That didn't help with this issue (though it did resolve a different issue!!)

One thing I am starting to notice....

I am starting to see a pattern. Every time I see the printheads scraping the paper, these "dimples" show up in the paper.... this must be what's causing the dimpling.

They are always in a diagonal pattern, from bottom right to top left. They are spaced about 2-3 inches apart.

I believe they are being impressed into the paper on the printer somewhere... I unroll blank rolls of paper and cannot find these dimples anywhere. Also, it is happening on one Z6100, and not the other two.

I increased the vacuum pressure, and that seemed to help, though it didn't resolve the problem completely.

Thanks,
Jon

Edited by: Jon Kovach on Jun 18, 2008 5:36 PM

[jonkovach]

Well, my problem is evolving into something more... the printheads continue to scrape the paper, but now sometimes they actually catch the paper and tear into it. I have attached a couple pictures for you all to see. HP tech support hasn't come up with anything yet, but hopefully these pictures will speak to the problem a little better.
It is happening on all three of my Z6100s. The scraping/tearing always seems to be on the left half of the printer, never on the right side.

I am posting this, in hopes that someone can help me. If not, once I figure out what the cause of all this is, I will repost the solution - or at least what was going wrong... hopefully this will help someone.

Thanks,
Jon

[jonkovach]

In case anyone else is having this problem, I wanted to post this white paper from HP....
It was given to me by another poster. Thank you so much!!
Jon

http://www.outbackphoto.com/printing...ra_Stripes.pdf

[jvicars]

To change the height of the printheads, go to the printer settings portion of the control panel (the last entry on the display) and choose "Select Altitude". You'll be able to choose from one of three settings.

J

[dgarczynski]

We has the same problem with our Z2100's. I got our humidifier fixed and keep it at 40%-60% and the problem has pretty much went away. We also let new rolls of paper acclimate to the room before printing on it.

doug

[Rick61]

I increased the vacuum pressure, and that seemed to help, though it didn't resolve the problem completely.

Thanks,
Jon

Hi,

How exactly did you increase pressure ? I'm trying to do something opposite with z6100 and don't know how.

Thanks,
Rick