feeder probs

hi guys, i have a problem. my DI classic is playing hard to get. it is having a feeder issue. when feeding the sheets through it will miss a sheet or 2. u can hear it sucking. all adjustments on pile etc i have checked and redone. if the machine is under impression it comes up with the feeder symbol. which means either pile hieght or missing sheet.

but as stated above just on the through sheet feed it will feed then miss a sheet or 2 then feed again. then sometimes it will late sheet and i think this is to do with the missing the sheet.

i have checked the suckers and blown compessed air through them. i have cahnged 11b2 switch shut off s68 and s69 changed 3/2 valve. cleaned all forward rollers. i have ordered new suckers which will arive monday. i can't think of anything else.

can anyone other a idea?

cheers

also where is the s22 senor located???

 

The S22 sensor is the white sensor in front of the pile. It tells the press when you have raised the pile up high enough and will not allow you to go any further with the pile raise button.

I have a few questions:

1. What is the weight of the stock your are trying to run?
2. Does it do this with all types of stock?
3. Can you raise the pile to the top thick line?
4. Is there air blowing through the front air bar at the lead edge of the paper?

Mechanically I would check the springs which operate the pile height mechanism. I am going from what little I have left of my memory, but I believe there are supposed to be two of them. I seem to remember it is not unusual for one to break or come off. When this happens it cause the pile height mechanism not to work properly.

Also I would check the sucker bar swing mechanism. There is a small nylon bushing which makes it work. I have seen this bushing deteriorate causing it not to feed well.

Feeder timing can be an issue, check all the cam followers tha operate the feeder mechanisms, especially the one on the first cam towards the side frame. It is hard to see and typically it is not noticed that it has worn.

 

Hi Paul,

it is doing it on all stocks, 90gsm, 150gsm 200gsm 250gsm and 300gsm.

all springs are good, i even replaced the spring on the o.s. to the heavy one from my other DI which was a feeding issue last year for it.

the air is blowing out the front and the pile is going to the top black line. it doesn't seem to have a pattern. could miss feed at 5 or 250. 2 sheet after the pile has risen or 6 sheet after the pile has risen.

where is this nylon bush located on the sucker bar?

also the pile hieght senor i thought was s21?

the cam followers are these the little bearing type rollers that are bolted on the arms which work the forward rollers? if so they seem to be find.

the machine has only just clicked over the 9million

cheers
shane

 

I stand corrected on the switch, the pitfalls of an aging memory...

The nylon bushing is rectangle shaped with a hole in the middle. It is what makes the sucker bar flick the sheet into the press. They used to be white and then were changed later to a harder black nylon.

At 9 million impressions the bushing should be fine if it has been lubricated on a regular basis.

You may have other issues going on also if these items you checked are fine. The other issues will require a knowledgeable technician with the proper tools to chase down. Like infeed wheel timing, feeder drive gear backlash and feeder to press timing.

 

thanks Paul, i have a tec hopefully turning up next week. As i think its the timing of 11B2 which needs and access code to set it in the machine.

cheers

 

The 11B2 is part of the timing issues I mentioned. This switch is responsible for the pile height working correctly, it is also dependent on the backlash of the gears which operate it.

The technician should be familiar with it and get you up and running.