SM52 water speeds to high

[Apphoard]

My water speeds are to high on my sm52. I know I can add more etch and alc. sub. But that creates more problems like blinding. I have new water rollers and know I have the rollers set correctly. I run de-integrated always. We also have a QM46 I cannot even come close to running his water is my point the plates wont even clean up. I have 14 years experience running a press and never had problems like this. We run Pressteks Freedom Pro plates which require to much water to begin with. But sice I cannot come close to running the QM water makes me believe there is something wrong on my press. Any help would be greatly appreciated.

 

[Ret Heidelberg Instructor]

First of all, I would like to ask some questions to possibly help you out. Your feedback will be very helpful. How old is the press? What do you consider high water speeds? You said that your water rollers are new, which ones? Is the water pan roller half crowned?
What is your Pre-dampening and Post dampening set at? Good settings should be Chrome roller to Dampener 5mm you could go a little heavier also, Dampener to Distributor 5mm and dampener to plate 4mm. Ink forms to plate 3mm. Ink ductor to Ink Fountain roller 4mm (critical) Did you check the Night Latch position with the press off? Is the plate similar to polyester or a you running metal? If you engage the ink rollers to the plate and get a solid and then try to put the damps on, how many revolutions before the plate is clean?
To backtrack a bit when did the problem occur? If you run with the bridge roller on are things better or worse? Sorry to ask all these but if were in your shop these are the same things i would address to try and solve your problem Ask yourself what changed and when did things start to go bad?

 

[Apphoard]

The press is a 2000 SM52 2 color. My waters are running around 70 with little coverage. Both the pan and water form are new about 3 months old. I asked for no crown on the pans because several people suggested it. The rollers are from Bottcher. My pre-dampening is at 4 and the post is at -23. I use to run that at 0 on other presses. But it's been at -23 so I left it. I have my form to chrome at 7mm. The form to matte at 5mm. The form to plate is 4mm. The ductor is at 4 to 5 mm. I didn't know there was a night latch on the SM52. We are running metal plates from Presstek. If I drop the forms let it ink up and then drop the water. It takes around 20 revolutions for the plate to clean up with the forms still down and water on. I have never tried running the bridge on because these plates like so much water I am almost positive it would emulsify. It has ran like this since I got here two years ago. It runs better now than when I came. I really appreciate the help!

 

[Ret Heidelberg Instructor]

In my opinion The Water Chrome to water form is set a bit too high. Try 5-5.5mm that should be enough. The water pans on these presses had a half crown when new (around 5 degrees) 10 if you run with alcohol. The whole idea behind the night latch was to eliminate the need for backing off pressure from the Pan roller to the Waterchrome at night.
When setting the Water Pan roller to the Water chrome, you back off the water pan on both sides with the 5mm wrench until you see heavy water right across the roller.If you have a half crown pan roller, as you start to tighten the screws, you would see that the middle would lose the heavy water look first. You would tighten the adjusting screws on both sides until there is no heavy water visible and then add an extra 1/8 to 1/4 turn. Since you say you have no crown you still have to meter out the heavy water.
The night latch sets as follows: Turn the press off and bleed the air out from the press at the feeder behind the door. You should be able to put a .10mm feeler gauge or .004 thou in between the Water Pan and the chrome. If it is to tight you have to release the pressure. There is a recessed screw on top of the bracket housing on both sides that needs to be adjusted. If there is too much of a gap in the night latch you will get to much water on to the plate when the dampeners come on.
You can visually check how much water comes on to the plate when you put the damps on. Shine a light into the dampener and watch the action of the roller when the dampener comes on. The water chrome seperates from the pan roller briefly and spins rapidly before slowing down. If your night latch position gap is to big you will get loads of water. Remember to bleed the air of every night.
In my opinion if everything is set correctly and you roll up a solid on the plate, take off the ink forms and in 3-5 revolutions your plates should be wet and have cleaned off the ink. Try this and see what happens. I hope I have explained the night latch in a way that can be understood.

 

[Apphoard]

I understood the explaination of the night latch. I did not know about that setting. So I checked the night latch setting I could slide a .004 across all the way on both units except on one side on the 1st that I knew was to tight because of a flat spot I had some extra pressure. I have a new roller coming and will check that again when I install it. The recessed screw is the flat head on top of the bracket for the adjustment of the night latch? I will try the dropping of the forms tomorrow again but I will take them off before I drop the water on. I believe when I have the form to the chrome set at anything lower than 6mm my water speeds are higher. Does that sound right? I appriciate your help!

 

[Ret Heidelberg Instructor]

It is not the flat head screw that adjusts the night latch. There is a recessed screw hole that is directly on top on top of the bracket that has the flat head screw. It is slightly hidden and you need a ball driver Allen wrench to turn the set screw. You have to access it on an angle. Sorry I can't remember the size of the Allen wrench that fits. Start with a 5mm and work down. You do not have to turn it very much. Just release it enough to get the feeler strip through unrestricted, it has a fair bit of resistance. If you set the Water Chrome to tight you create more surface tension and might have to move the speed higher. Start with the lower settings 5-5.5 mm. I don't know where you got your info on having no crown on the water pan roller. The half crown was used so that you could run with alcohol or alcohol free. In Europe a lot of shops like to still use alcohol. With a crowned roller, setting the night latch eliminates creating a flat spot in the center of the Pan roller. When you shut down the press at night and bleed of the air the Chrome roller will seperate from the water pan roller. The feeler should move freely across but not too loose. Do not adjust the flat hesd screw. Hope this helps.