the speed and efficiency of the make ready process on a sheetfed press i feel has more to do with accurate inking. any pressman worth his salt should be able to get a decent handle on dampening variations.
but if you eric can wrap yourself around this one i think it could provide a little insight as to some of mysteries we face.
lets go back for a minute to the pre cip3 and cip4 days.
there were times when my initial settings on all of the plates we pretty darn accurate. as a matter of fact i usually trust them more than i do current cip data. well now try to remember how every now and again youd get that mystery job that would require really large fountain settings in a zone with zero or close to zero ink takeoff.
ever wonder where all that ink was going???? .
Tom, as usual you have very good comments.
The unfortunate fact about CIP3/4 is that a lot of effort has been made to get a standard method to get ink key presetting data to the press but very little effort was made to make that data accurate. The ink consumption requirements of a job are NOT directly related to the image coverage area on the plate. If you use the simple model for ink consumption based on the ink key zone image area alone, the errors can be as high as 40%. Ink consumption per ink key is job related and also press related. I covered this issue in my 1997 TAGA paper.
It is no surprise to me that on some jobs, your manual methods resulted in good results and at other times they did not. I had developed an experimental positive ink feed system in the early 1990's and it was run in production. We got image coverage data from a plate scanner and this was then used to set the outputs to the pumps used for each ink key. Some jobs were preset well and others were not.
Of course this was a problem because I also did not understand the cause but after a few months I realized where the error was. There error was in the knowledge base of the industry. I had assumed that what the industry had been saying about the relationship of ink consumption to image area was true. Actually it was grossly wrong. That misinformation wasted a lot of money and time because this experimental technology was partially dependent on accurate ink key presetting data.
I started to understand that the industry does not have the specific kind of knowledge that can be used to develop future technologies. That is when I started to develop a science myself based on a more in depth analysis of how things work. The good news is that many things can be explained and better still there is a great potential to make significant improvements that do not require large costs.
My quest is not just to make presses more consistent and predictable but to lead the industry in a direction that develops better theory that can actually be use to develop technologies, both hardware and software, that will have consistent and predictable performance at low cost.
Even today, the science and technical community in the printing industry use experimental results and a collection of confusing and faulty ideas of how the process works to develop technologies that are based as much on "I hope this will work" thinking as on engineering skills.
This goes for the engineering schools in Germany that specialize in the printing process and technology. I have seen recent PHD work that took many years of effort and which has been presented at graphic technology conferences, that will have basically no chance of resulting in any successful conclusion. It is so sad because it is quite easy for me to see that some basic questions were never asked that would have stopped the effort a long time ago. But it seemed clear that that engineering school had no idea of the implications of their concept.
Industry does this all the time too. Remember the single fluid ink from Flint. Promoted strongly at a previous Drupa as a potential new technology. Nothing wrong with the idea of a single fluid ink but it needs to pass a simple test. If it can't pass the simple test then it will not work. Having some theoretical understanding of what is required very easily tells what that critical test needs to be. Instead, Flint just thought that a bit more effort in the ink lab would make it successful. They were fooled into thinking that if one was at a 90% success point, that the additional 10% would not be a problem. Many times the last 10% is impossible to obtain because of some factors that were not understood. You don't hear about Flint talking about single fluid ink anymore. That must have hurt.
It happens to press manufacturers too. Goss had a Positive Keyless Inker press concept and it was a total failure. Not hard to understand why. I analyzed it in 1996. If they would have had the ability to analyze their own press concept, they would have avoided wasting a lot of money. They installed a few and had to modify many of them back to normal ink fountain inkers.
Good science not only leads to better technologies but it also helps prevent wasting money and time doing the wrong thing. Or buying the wrong thing.
