Standard Finishing
4Over

Announcement

Collapse
No announcement yet.

Pressure issue???

Collapse
Canon
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Pressure issue???

    I run a Ryobi 3302M with Crestlines. We've had it a year, got it used, and it has always had a problem with laying ink down. We've changed every rubber roller, I use Ryobi blankets and under blankets. I have tried four different inks, Spinks, Superior, Kohl/Madden, VanSon's CML, and all print the same way. Under a loupe (often times without a loupe) you see white speckles. Presstek services the machine and they've had five different technicians work on it and failed to fix it. They say the press is at spec and it's a problem with the ink or the wooden floor I operate on. The thing is, this press replaced an older Ryobi 3302M with twice the impressions and we used the same ink, water, everything and didn't have this problem. If I over pack the blanket by about 8 mil, it prints pretty well, but they tell me I'll ruin the press by doing that. Three of them were here all day yesterday and today it prints worse than it did last week.

  • #2
    Re: Pressure issue???

    The response you are getting from the service technicians seems pitiful! How do they explain the fact that your earlier 3302M did not have this problem? I assume on the same floor location. If the press is up to spec, then why is it printing poorly? Does your purchase contract have a print quality clause? It's unfortunate that a whole year has passed with the problem not resolved.

    Increasing the blanket packing changes both Blanket/Impression squeeze and Plate/Blanket squeeze. Have you explored just adjusting the Plate/Blanket squeeze? I know this is obvious, but you did not mention it.
    Is the problem localized on a tabloid sheet: towards the lead edge, the tail, side? Is it every _consecutive_ sheet, or every _other_ sheet (double sized impression cylinder)?

    Why did you replace the earlier 3302M with this one?

    I also have a 3302 with Crestlines and I have no such problem.

    Al

    Comment


    • #3
      Re: Pressure issue???

      Yeah, we get that a lot from other people with the same press, they love it. We replaced it because it was extremely old, in fact the best guess to its age based on the serial # is about 30-35 years old (who knows if that's right). In any case, I didn't like the Kompacs and it had more parts breaking every week. It wouldn't stay in operating condition. Presstek took this one in on trade for a DI from a local shop, we saw it before the picked it up and talked to the former owner about it. The only thing he used it for was four color work. He took rather good care of it and Presstek had been servicing it. They gave us a good deal on it.

      To answer your questions, it is every sheet, the entire sheet. I have played with the plate pressure but what I ends up happening is the packing causes the blanket and plate to be in constant contact so I have to back off the plate pressure or it loads my blanket with ink. I have tried adding and subtracting plate pressure. The techs left it with plate pressure "to spec" for the plates I use. Some people have suggested chemistry is the culprit so to rule that out I printed without water, blanketing the sheet with ink and it prints the same way so it seems mechanical, but it is to spec.

      Who services your press?

      Comment


      • #4
        Re: Pressure issue???

        Jeremy,

        Ptek is a company that wants offset users to suffer and switch to the digital products they peddle, like the 34 and 52 that compete with toner copiers etc..............Any way I will add this:
        First ink up a solid plate no water to plate
        Pressure Plate to Blanket with say a .006 metal plate set gauge to like .14 to .16 and stripe the blanket just use the nut on the pressure link. Should be 5/32-3/16” nice even stripe if not parallel is off!
        Next ink up the blanket solid and do a stripe from impression to blanket you want at ¼” or better stripe to print nice solids etc. Set pressure dial on .0. Just use the bare cylinder to measure the stripe.
        I wonder if ryoboe knows the lack of support that certain vendors offer? IMHO Ptek should be ashamed of the tech support they offer.

        Best of Luck
        OG

        Comment


        • #5
          Re: Pressure issue???

          Thank you both for your help, but my problem is still unresolved. My plate to blanket stripe is 5/32, my blanket to impression cylinder is actually heavy, 5/16. That wouldn't cause the problem, though, would it? I've coated a sheet with ink, the water off, even put smooth lith in the ink, no change. That would rule out chemistry as other people have suggested, would it not? Perhaps I should contact the local Ryobi dealer about a contract. Any other suggestions?

          I agree about Presstek, though every time I accuse them of poor service because we don't own a DI, they deny it. However, I have noticed that their more competent mechanics work on the DI's and not two colors.

          Comment


          • #6
            Re: Pressure issue???

            Jeremy,
            White speckles showing thru the paper indicate mottling. Hard to tell without being there.
            Grab a sample of ZIPSET ink black XLR!!!! Just Google the name. The pigment level in that ink is very high!
            Also run a dry solid NO WATER NO PLATE just bare cylinders. Just max the pressures out see what happens.
            If you still have poor coverage let me know…….That press will lay down down a decent solid.

            Worst case is contact Ryobe and ask for a competent technician that cares. I even hear complaints about the service on the DI's machines and the type of reps they Stresstek send. Most of the reps have gotten fat and lazy and just wish to push a mouse. Why people spend 300K-500K for these machines is beyond me....once the warranty expires they got you.

            There are many new independent service groups that can help people like you, I am in the process of setting up a web site that will list good techs around the country that can service small press problems.

            OG

            Comment


            • #7
              Re: Pressure issue???

              I was afraid to use the "m" word because it's been my experience that mottling means different things to different people. Some people have told me that this is mottling and some people have told me it is not. I did the dry run, no water, no plate, max pressures, the solid still looks the same. I tend to run a dense black to try to hide this problem, but I run into problems with PMS colors. I can't push them because they won't be the right color and if I don't, they look light.

              I understand these presses aren't bearer to bearer and that the blanket cylinder moves up and over to make plate and impression contact. Could there be something out of whack inside that is not allowing it to make consistent contact or holding in impression? I ask this because it would make sense to me that if I run a thick stock, like 14pt coated stock, and I squeeze it more than I should the image should get better, but it does not. Similarly, if I squeeze text, it looks consistent with cover. But if I over pack the blanket about 8 mil, it seems to be better. Almost like there is play in the blanket cylinder and the excess packing holds it tighter...does that make sense?

              Comment


              • #8
                Re: Pressure issue???

                Jeremy,

                I am baffled. Without seeing your machine and samples I find it hard to trouble shoot your problem. Are there pits in your form rolers?
                I mean a BARE dry solid with all pressure's maxed out should tell us some thing.

                The PMS books are printed dry offset and the ink lay will get no better than what you see there. Some colors due to pigment look mottled, IMHO.

                Maybe call Riceobi and send samples?

                BOL
                OG

                Comment


                • #9
                  Re: Pressure issue???

                  Here's your problem.........Your trying to print with a toy.Iteks are actually just about extinct where I am...Perth Western Australia.There are still a few desperado's who still use them, they are only good for simple two colour work. Believe me I used to have one & produced process work off it, but at the end of the day your trying to produce work it wasn't designed to do.......But printers being printers we want to push the envelope as far as we can. do yourself a favour & buy a bearer to bearer press & you'll have no problems.

                  Comment


                  • #10
                    Re: Pressure issue???

                    Agreed, and if I had my choice I'd be running a Quickmaster, but this press SHOULD print better than it does. I'm not trying to print an 11x17 solid or anything, but even simple stuff like bold text looks like crap. It would look better on the ABDick 9810 that we currently use as a shelf.

                    As far as the dry run thing, I keep my cylinders really clean and ink doesn't stick very well to them. The last time a (Offset Guy said it best) Stresstek technician was setting my stripes, he couldn't get ink to stick on the impression cylinder. It was a first for him. That might be throwing it off. I appreciate all of your input and will let you know what happens. Thanks.

                    Comment


                    • #11
                      Re: Pressure issue???

                      New discovery.

                      The Presstek technician came in yesterday and replaced some linkage that he thought was worn and allowing the blanket cylinder to move and not give a solid impression...he was wrong.

                      However, in testing the new parts, we put the same black ink in both units and number 1 is saleable, and number 2 is still just as awful. There is a noticeable difference in print quality between the two. Blankets are both new, water and ink are the same, all the stripes are correct...anyone have any ideas? I do the majority of the printing on the second unit so the image doesn't slap on the second unit when I do single color work. We've replaced all the rollers in both units at the same time, none of them appear pitted. I'm at a loss. Why would one unit print better than another if everything about them is the same?

                      Help? Anyone?

                      Comment


                      • #12
                        Re: Pressure issue???

                        Jeremy,
                        It sounds like unit 2 is losing pressure when it prints. The blanket cylinder on that machine is the only one that moves. It moves up to image and forward to Impression. You can view the linkage movement while it prints with the proper side covers taken off. You stated if you pack your blanket .008” it prints ok….so some where you are losing the thrust of the cylinder on unit 2 under power. If you look at the V design of that machine unit 1 pressure is supported via the IMP cylinder which is fixed and Unit 2 the linkage only.
                        It is very hard to diagnose over the internet but if I were you I would call Ryobi directly and ask them. Or find another tech company. The wooden floor you stated you have is kind of shaky? Maybe that is the issue? Slid the press down to where unit 1 is and test it. The rails the 3302 are built on may be bowed or flexed a bit.
                        I had one 3302 that printed poorly and had severe gear marks on the blankets. I replaced the gears and bearings in the plate and blanket cylinder and it never solved the problem. After I ran a machine history I found out the 3302 was dropped when it was delivered.
                        Best of Luck
                        OG
                        PS: My replies to you have gotten me in trouble with:
                        Name: Andrew Yates
                        Email: angela_yates@optusnet.com.au

                        Registered: Apr 9, 2008
                        Total Posts: 3
                        Job Title printer / director
                        Company printsmart
                        Location perth aust
                        Company Type Printer

                        He is cursing at me etc…….so I will make this my last reply.

                        Comment


                        • #13
                          Re: Pressure issue???

                          I'm sorry you got yelled at by Yates. I don't know where he gets off cursing you out for trying to help me out. He's entitled to his opinion but my problem wasn't a question of which press is better, but why this press wasn't printing to its capabilities.

                          I ran the press with the covers off to look at the linkage and discovered that the brake that holds the second unit's blanket in impression was loose. When the sheets ran through, they effectively pushed the blanket away instead of vise versa. I had my technician come in to fix it, he tightened it down (although he tightened it too tight and I had to loosen it today because the blanket wouldn't come off the plate) and now it prints fine. I don't know why we pay for a service contract when I seem to find all the problems for them. By the way, the Ryobi dealer in the area is most commonly and accurately described as a pompous prick and I was reminded why when I called him about a service contract. His reply was "we don't do service contracts because we're too good for that." He also called a local, independent mechanic a drug dealer and said bad stuff about Presstek, too. I just can't do business with a guy like that.

                          Thank you for you help, Offset Guy.

                          Comment


                          • #14
                            Re: Pressure issue???

                            Good job Jeremy!

                            On any wierd pressure problem I always remove the covers and observe the operation of the linkages and cylinder movement hardware. I took for granted you had trained techs working on the machine that would have done the same.

                            You should purchase a service manual and fix it yourself. I feel bad for you if that is the level of service you recieve in your area.

                            Glad you resolved it......

                            OG

                            Comment


                            • #15
                              ph / conductivity would be my first step.Ph would be 4.1 to 4.4 to start and conductivity would be about 1800 at start.All rollers would be in contact with plate and transfer rollers transferring properly.Pressures would be with in press manufacture specs.Another thing about the water you are supplying to the press , is the water straight tap or is it RO water.Blanket wash could be your culprit as well.

                              John Crisp

                              Comment

                              4OverStandard FinishingDuploSmartsoft (Presswise)AleyantCanonKBA
                              KBAKBA

                              What's Going On

                              Collapse

                              There are currently 4261 users online. 85 members and 4176 guests.

                              Most users ever online was 6,597 at 10:25 AM on 04-20-2018.

                              Working...
                              X