Web 8 ink key zero setting

[rugerred]

I am looking for the proper way to mechanicly zero the ink keys on a mid "80"s Heidelberg web 8. I know how to set the newer Harris presses but cant find any information for the older Web 8.

 

[Deleted member 16349]

I am looking for the proper way to mechanicly zero the ink keys on a mid "80"s Heidelberg web 8. I know how to set the newer Harris presses but cant find any information for the older Web 8.

Does this press have a ductor roller or a continuous (ductor) metering roller?

 

[rugerred]

It has a ductor. Im looking to zero set the keys to the fountain ball and cpc readout.

 

[rugerred]

Any thoughts Erik?

 

[Deleted member 16349]

Any thoughts Erik?

If you had the continuous metering roller system, there is a method that I would have sent to you. Not perfect but quite good.

I don't have a method for the conventional ductor system. Even though there are methods based on measuring the ink film on the ink fountain roller, determining the actual point of zero transfer into the press is a problems since it changes as conditions change on the press.

Sorry I can't be of more help.

 

[rugerred]

Thanks anyway. I think I can do it by setting the electronic zero / discontect motor and then mech zero the key to an ink film / reinstall. I just wanted some ideas beyond that.

 

[blazini]

... Even though there are methods based on measuring the ink film on the ink fountain roller, determining the actual point of zero transfer into the press is a problems since it changes as conditions change on the press.

.

theere is no "zero transfer" setting on a ductor fed press. There will always be some ink transfer from the ball to the ductor. At the point where there is "zero transfer" the fountain blade is touching the ink wall. Zero transfer can only be achieved with a continuous feed system. Any point at which ink does not tought the metering roller is zero.

I'm sure there's some scientific method for setting them precisely but it's hardly worth the effort. Blade wear and warpage will never allow you to maintain precise settings.

I don't know anything about the specific ink keys on your press, but on ductor presses I have always set the console at zero, then set each blade segment until is tapped the ink ball then backed the key off a hair, just until it doesn't touch. Run the keys up to 20% and look for consistant film. Then to 50% and back down to zero. if a key touches the ink ball it needs to be opened up. I usually never have to pull a servo out to set a key. Most setups use a double threaded shaft from servo to ink key. You can usually adjust the manual adjustment without turning the servo. I only pull the servo out if the manual side of the shaft isn't even with the rest of the keys. Of course your press may differ.

 

[Deleted member 16349]

theere is no "zero transfer" setting on a ductor fed press. There will always be some ink transfer from the ball to the ductor. At the point where there is "zero transfer" the fountain blade is touching the ink wall. Zero transfer can only be achieved with a continuous feed system. Any point at which ink does not tought the metering roller is zero.

.

Normally I would go into a long explanation to correct your view but no point doing it these days.

I will say that you probably don't observe what your press actually does. As an example, if you have some of the ink keys closed so it does touch or almost touches the ink fountain roller, I would expect that you would see clean steel when the ductor has not touched the ink fountain roller and then inked steel when the ductor has touched the ink fountain roller. That says to me that your are actually having ink feed back from the press to the ink fountain.

 

[rugerred]

Blazini is correct in that you always have a very thin film of ink on the ball. If you did not you would wear the keys in very short time. The film is actually thin enough that it doesnt transfer. I was looking for the mech way of setting the Web 8 keys. They have an odd servo setup

 

[Deleted member 16349]

Blazini is correct in that you always have a very thin film of ink on the ball. If you did not you would wear the keys in very short time. The film is actually thin enough that it doesnt transfer. I was looking for the mech way of setting the Web 8 keys. They have an odd servo setup

Yes he is correct in that a thin ink film is required but in that situation, when the ductor hits the ink fountain roller, it applies a thicker ink film to the ink fountain roller, meaning ink is coming form the press and back to the ink fountain.

The zero set point is a point where there is no "net" transfer of ink from the ink fountain roller to the press. It is a "net" ink transfer of ink because ink is actually being transferred in both directions at the same time even at non zero set point conditions. This can be seen when backtrapped ink goes back to the ink fountain.

Lack of accurate zero setting is related to the lack of control of ink feed.

 

[blazini]

Normally I would go into a long explanation to correct your view but no point doing it these days.

I will say that you probably don't observe what your press actually does. As an example, if you have some of the ink keys closed so it does touch or almost touches the ink fountain roller, I would expect that you would see clean steel when the ductor has not touched the ink fountain roller and then inked steel when the ductor has touched the ink fountain roller. That says to me that your are actually having ink feed back from the press to the ink fountain.

Eric, have you ever actually ran a press? You would have to do so before you can correct me on this.

Ink can only feed back from the roller train to the ink ball through the ductor when the press is moving. On any press with a motorized ink ball (just about any press with remote keys), you calibrate the fountain when the press is down. Turn the ink ball on and inch the press until the ductor cam retracts the ductor from the ball, or you just remove the ductor. Since the press is not moving the ductor is not driven back and forth.

As I said, there is NO ZERO TRANSFER setting on a ductor press. At this point the ink blade is touching the ink ball. I don't care whether it's a segmented or or single blade, there is always ink film on the ball when it is calibrated correctly. This is also the case with continuous ink feeds. The difference is that the ink film has to reach a certain point before the ink bridges the air gap of the metering roller. On continuous feed systems there is a "zero transfer point" but there is never a point where the ink ball does not have a film of ink.

 

[Deleted member 16349]

Eric, have you ever actually ran a press? You would have to do so before you can correct me on this.

Ink can only feed back from the roller train to the ink ball through the ductor when the press is moving. On any press with a motorized ink ball (just about any press with remote keys), you calibrate the fountain when the press is down. Turn the ink ball on and inch the press until the ductor cam retracts the ductor from the ball, or you just remove the ductor. Since the press is not moving the ductor is not driven back and forth.

Now I see why you said what you said. When you are setting the zero set point, the press is not moving. Yes I can understand that but the importance of the zero set point is when the press is moving and printing.

Also in your earlier comments you stated that the ink always went from the ink fountain roller to the ductor. If the press is not running how could this be so.

I am happy to see that you agree that ink can transfer back to the ink fountain from the ductor when the press is running. That was my point. Zero setting is an attempt to find that point where there is no net ink transfer in either direction.

Good luck with your zero setting efforts.

 

[blazini]

Now I see why you said what you said. When you are setting the zero set point, the press is not moving. Yes I can understand that but the importance of the zero set point is when the press is moving and printing.

What? Honestly Erik, I'm beginning to lose faith in your knowledge. You only set a fountain with a gear driven ink ball while the press is running. On a press old enough to have a gear driven ink ball it will also have manual ink keys.

Also in your earlier comments you stated that the ink always went from the ink fountain roller to the ductor. If the press is not running how could this be so.

When the press is off and you are calibrating the fountain it's not so. When the press is running it will be so. When I say that I mean that there is now way to shut an ink key OFF, which is precisely what I am trying to explain to you here. Just as I said, when you calibrate a fountain you will calibrate it with a bare minimum of ink flowing through that key section. When you start the press and engage the ductor drive, the ductor WILL come in contact with that a thin film of ink.

I am happy to see that you agree that ink can transfer back to the ink fountain from the ductor when the press is running. That was my point. Zero setting is an attempt to find that point where there is no net ink transfer in either direction.

I do agree, ink can back flow to the fountain, but this thread is about a zero blade setting isn't it? That does not influence the 0 point blade calibration in any way. The 0 blade setting is once again the bare minimum ink that will flow to the ink ball, the ductor plays no role in this.

 

[Deleted member 16349]

What? Honestly Erik, I'm beginning to lose faith in your knowledge. You only set a fountain with a gear driven ink ball while the press is running. On a press old enough to have a gear driven ink ball it will also have manual ink keys.


I do agree, ink can back flow to the fountain, but this thread is about a zero blade setting isn't it? That does not influence the 0 point blade calibration in any way. The 0 blade setting is once again the bare minimum ink that will flow to the ink ball, the ductor plays no role in this.

On a web press with a continuous metering roller, we had the press operators set the zero set point with the rollers running. This was very effective. This press also had a motor drive to the ink fountain roller. Of course that method can not be used on a press with a ductor.

I disagree with the comment that the ductor plays no role. This may be due to our different definition of what the zero set point is. My definition is the point where there is no net transfer of ink into the roller train. With a bare minimum setting of ink film on the ink fountain roller, ink will transfer back to the ink fountain when the press does run. This would not satisfy my definition.

If your definition of zero setting is to set a minimum ink film on the ink fountain roller, that is your definition but that setting does not ensure the purpose of what the zero setting is doing, IMO. For me, zero setting is the datum point for ink key percent moves. For me zero setting is a different position than the minimum ink key position set to prevent contact with the ink fountain roller. The press I was most familiar with, both positions could be set.

If your zero setting is mainly to ensure the ink key can go to a minimum position so there is no unwanted ink going into the press, then we have different goals.

 

[blazini]

On a web press with a continuous metering roller, we had the press operators set the zero set point with the rollers running. This was very effective. This press also had a motor drive to the ink fountain roller. Of course that method can not be used on a press with a ductor.

I disagree with the comment that the ductor plays no role. This may be due to our different definition of what the zero set point is. My definition is the point where there is no net transfer of ink into the roller train. With a bare minimum setting of ink film on the ink fountain roller, ink will transfer back to the ink fountain when the press does run. This would not satisfy my definition.

If your definition of zero setting is to set a minimum ink film on the ink fountain roller, that is your definition but that setting does not ensure the purpose of what the zero setting is doing, IMO. For me, zero setting is the datum point for ink key percent moves. For me zero setting is a different position than the minimum ink key position set to prevent contact with the ink fountain roller. The press I was most familiar with, both positions could be set.

If your zero setting is mainly to ensure the ink key can go to a minimum position so there is no unwanted ink going into the press, then we have different goals.

Its not "my method", it's every presman i've ever knowns method. If you dig up a press manufacturers operating manual (with remote inker), i'm sure you will not find them stating that the fountain should be set with the ductor engaged and running either.

 

[Deleted member 16349]

Its not "my method", it's every presman i've ever knowns method. If you dig up a press manufacturers operating manual (with remote inker), i'm sure you will not find them stating that the fountain should be set with the ductor engaged and running either.

Good luck with your setting efforts.

 

[blazini]

Good luck with your setting efforts.

Well I've been running a continuous ink feed press for a few months now and haven't had the desire to touch a fountain since. Good luck with that thing you're selling.