QMDI classic feeder issues

Hi,
We have been having the same problem with the feeder on our DI for about a year now, you can be feeding card one minute and then the pump just switches off for no reason and the press stays running.

Another thing it does is the press can just stop, but the lights on the consoles are lit as if the press is still running and it wont start again until you press stop and then start then the press starts again.

We have had the feeder rebuilt new pump, new 3/2 way valve and various other parts replaced, its cost a fortune and its still not right, has anyone else had this, what was causing fault?

Many thanks

Calvin

 

Try printing on one unit at a time and see if it keeps running. It is possible you have an air leak in one of the short stroke pistons which put each unit on impression. If one of these are leaking (There are 2 per unit.) the air compressor will drop below 6 bars and shut off the press. The only way the press will start running again is when the air presure gets back up above 6.5 bars.

If by chance you find it is one of the short stroke pistons, I recommend you have it put on by a qualified technician. The air ram has to be measured exactly as the one that was in the press when replacing. If not you can actually cause the bearer pressure to change and cause the back lash in the helical cut drive gears to change as these are paralled at the factory. You won't notice it right away but a 1 year or so down the line you will have caused serious irrepearable issues with the print quality.

 

Hi Paul, thanks for that, we dont have an air leak we checked this first, any other ideas, thanks for your help.

Many thanks

Calvin

 

Calvin,

Tried calling you this morning.

Are there any error codes coming up on SF56 when you have the issue.

Regards.

 

Hi, Sorry I missed your call, there are no error messages.

Cheers

Calvin

 

when you run the paper without printing, the press doesn't stop if some of the sheets are not feed in.
Going on printing is different, by missing sheet press has to stop, otherwise would print on the metal cylinder
and then on the back of the paper.
Probably it is your problem, due to the wrong settings on the feeder, or caused by the worn mechanism of the feeder lifting control.
rgds
Jan

 

Our QMDI Plus will not feed when we use all 4-units on impression it will print up to 3 at a time then with 4 it shuts down (as if a miss feed) The air pressure never drops below 7.5 bars so short stroke does not seem to be the issue. We know when the X7 is the issue as the vacuums rev way up every time it shuts down and that is not happening now.
Stumped???

 

Also when it shuts down all units shut off except the magenta. So when you start up again only the magenta unit is turned on unless you remember to turn on the other 3.

 

one last thing. When it shuts down, the press is always out of time and we have to re-timeto the correct positions.