BH-423 with FS-527, paper curling

[Hansoon]

Sheets are coming out of the finisher with a slight curl at the leading and, lesser, at the trailing edge. As long as they are printed on one side they stack more or less OK. However, duplex sided prints are very often touching with the leading edge the stack of previous prints and than the mess starts ( see attached picture).

Since this is exactly the same type of paper the customer uses since many years I suspect somehow wear out of parts in the sorter. Or what do you guys think?

Is there a way to let the lower tray of this finisher stay a little higher to reduce the angle with which the ejected sheets touch the stack of finished prints?

Had not much time to spend on it yet but would love to hear any suggestions from you guys.

Hans

[splblazer91]

Re: BH-423 with FS-527, paper curling

I havent found a "perfect fix" for this yet. My fix is to place a piece of mylar by the rollers on the front side of finisher so that it holds the lead edge of the paper off the tray for a little longer and doesnt allow it to curl under. Good Luck.

[allan]

Re: BH-423 with FS-527, paper curling

Sheets are coming out of the finisher with a slight curl at the leading and, lesser, at the trailing edge. As long as they are printed on one side they stack more or less OK. However, duplex sided prints are very often touching with the leading edge the stack of previous prints and than the mess starts ( see attached picture).

Since this is exactly the same type of paper the customer uses since many years I suspect somehow wear out of parts in the sorter. Or what do you guys think?

Is there a way to let the lower tray of this finisher stay a little higher to reduce the angle with which the ejected sheets touch the stack of finished prints?

Had not much time to spend on it yet but would love to hear any suggestions from you guys.

Hans

Don't think its wear. I had a brand new machine with that problem.
I played with 2 settings. I set fusing priority to production instead of quality and dropped the fuser temp with 15 degs.

A simple test for paper is to take the paper out of the tray and to turn it upside down. If the curl is much less then the paper is the problem.
Just take a fresh ream of paper along, but i do think its the machine.

[blackcat4866]

Re: BH-423 with FS-527, paper curling

I didn't think of fuser temperature at the time. The only way I could stop the spill over was to send all prints and copies to the upper exit tray. =^..^=

[habik]

Re: BH-423 with FS-527, paper curling

I have inclination to paper as well. Try the above suggestions or to print landscape. If it comes out straight, then they have off-cuts paper from the manufacturer. Paper industry is suffering, so savings are made everywhere, then we have nigthmares.

[splblazer91]

Re: BH-423 with FS-527, paper curling

Be careful dropping the fuser temp. Ive dropped them as little as 10 degrees and had to go back because it wasnt fusing properly

[srvctec]

Re: BH-423 with FS-527, paper curling

Be careful dropping the fuser temp. Ive dropped them as little as 10 degrees and had to go back because it wasnt fusing properly

Yes and the fix for prematurely failing fuser rollers on these models is to increase fuser temp by +5.

[Hansoon]

Re: BH-423 with FS-527, paper curling

Thanks for all your input guys. Will come back on it later cause I had to suddenly take over another territory. When back in my own I'll pick up the issue again with that customer.

Hans

[EarthKmTech]

Re: BH-423 with FS-527, paper curling

Yes and the fix for prematurely failing fuser rollers on these models is to increase fuser temp by +5.

How much longer does it make it last? Currently I can only expect 2 drum lives before having to change the fusing units on these at the factory setting. Some machines it has to be changed at every drum change.

[srvctec]

Re: BH-423 with FS-527, paper curling

How much longer does it make it last? Currently I can only expect 2 drum lives before having to change the fusing units on these at the factory setting.

Not sure. That's the official "fix" from KM (take that for what it's worth) and we just started changing all our machines whenever we go on calls to the higher setting. We haven't had enough time to determine if it really works or not. We get way more mileage out of aftermarket UFRs in these and just put in a rebuilt fuser when the original one fails early.

[allan]

Re: BH-423 with FS-527, paper curling

How much longer does it make it last? Currently I can only expect 2 drum lives before having to change the fusing units on these at the factory setting. Some machines it has to be changed at every drum change.

I use 3de party thermistors that does not scratch the rollers making them go much longer.
Why don't you rebuild them with B250 UFR's, that works well and saves a lot of money.
I understand why you change the units if you work for KM directly, the stuff is cheap enough that way.

[srvctec]

Re: BH-423 with FS-527, paper curling

Well, I guess when we need answers, we should just RTFM. I somehow stumbled upon a setting in the service mode of the 423 series that is specifically for curl control but the morons at KM don't call it that. It's called "Print Interval Extension" and specifically mentions it's for fixing curling issues. WTF don't they call it CURL PREVENTION??!!!

[blackcat4866]

Re: BH-423 with FS-527, paper curling

Please let us know if it works. =^..^=

[srvctec]

Re: BH-423 with FS-527, paper curling

Tried it on a 283 here in the office with the internal jaminator finisher, just to see if it slowed down. I first timed the machine without the change to get a baseline time. Then I made the change in service mode to "2" which means that curl prevention is on all the time. Did a reboot of the machine to make sure the setting took, and then verified it was still set afterwards. Ran the timing test exactly the same, expecting the result to be considerably longer since the setting name indicates it would extend the time between the sheets of paper. It was actually a couple seconds faster with the setting set to "2". Also, no difference in curl but with the internal finisher installed, I wasn't expecting any difference.

I'll try it on a troublesome curling 423 in the field when I go on a call for it and update here if it made any difference.

[tsbservice]

Re: BH-423 with FS-527, paper curling

Did you try to lower Fusing temperature in order to reduce curling of the paper?
Just FYI they(KM) called this function High Humidity PPM Adjustment in 8-series manual and Fusing PPM control in i-series