Speedmaster 52-5 not fitting.

Over the last few weeks we seem to of developed a problem with the fit moving on unit 4 & 5, it never seem to stay in a consistant position through a run, and quite often but not always the 4th & 5th unit has to be alot further out of square than it should be,to achive fit. I've also noticed that the 4th unit seems to be printing smaller than the other units. I've checked the grippers are clean and they are all well greased a moving ok. Thanks in advance for any suggestions
Rich

 

I would check cam followers, and condition of the jackets. These two things can quite likely cause fit issues. The most common thing I have found to cause fit issues is an impression cylinder received an impact. If there was a crash of any kind and has bumped the cylinder out of allignment, you will most definitly have a fit issue. How many impressions are on the press?

 

Thats interesting you should say that about the jackets because when it first started that was what i thought because the one on unit 4 was getting worn so i fitted a new one hoping that it would sort out the problem, unfortionatley it dosen't seem to of had any effect on it. There haven't been any crashes on the press as far as i know, its just so inconsistant with whats its doing its hard to nail it down. The press is 6 years old and has around 83 million on the clock.

 

When you say the problem is inconsistant, are you saying that sometimes you are having an issue and sometimes its ok? Is it a lenght issue or width issue? What kind of paper do you run when you see the fit issue? Other things you can check are make sure you are packing the blankets the same and setting the torque equally on all units. Make sure your back cylinder pressures are all the same. You may need to check back cylinder pressure not only by the value displayed on the screen but also by doing breakaways. What kind of jackets are on the impression cylinder? Are they factory jackets and if so are they black or silver? Silver jackets only come on one thickness, black jackets come in 4 different thicknesses. If you have all black jackets and you just replaced one, you need to make sure you have installed the same size that you removed. The last thing is try to see if you can get a Magnetic base and dial indicator. Measure the runout of all 3 cylinders on the printing unit(s) you are having an issue with. Optimum is 0 runout, but you should be able to get decent print quality and very little effect on fit with a runout no more than .025mm. If you dont have a Magnetic base most machine shops will let you rent or borrow one, its really the only way to know for sure if you have exhausted all other things.

 

It seems to be more of a length issue, than width. It seems to be worse when using grammages of 200 and above, it doesn't seem as bad when were using 130/150g. The packings and the blankets are all fine, the jackets are all the silver factory ones. i'll do some breakaways tomorrow and see what the pressures are like. The other thing i've noticed is we seem to be getting doubling aswell, do you think this could lead it back to the cam followers? Thanks Rich.

 

It absolutly could be cam followers, and you cant eliminate grippers either. You are starting to get into the impression count where grippers could be wearing out. Usually grippers start to become an issue at around 100 million impressions, but maybe if you are running more difficult work it could be earlier. cam followers are easy to check. on the impression and first/third transfer there is a collar on the gripper bar maybe between the third and fourth gripper. This collar has a threaded hole in it. You will need a 8mm x 50 or 60mm threaded all the way to the head. Screw the bolt in until you start to compress the springs on the gripper bar. This will lift the cam follower off the cam. Roll the press into a position where you can check the cam follower for excess wear. Only one extra step to replace the cam follower. Loosen the allen bolt at the cam follower and the cam follower will slide out the side. The cam follower will slide into a hole in the side frame. This hole is near the 12 o'clock position and accessed from the blanket washer side of the unit.

 

52 fit

Hi richck
Exheidmech sounds right, I have just overcome a problem with doubleing and fit issues on a roland that i am currently running, i had to go through all the grippers to get good sheet transfer, not only the impression grippers but check the transfer grippers as well . what we were getting was "flying gripper transfer" were due to badly set or worn grippers the impression grippers were letting go of the sheet a fraction before the transfer grippers had a good hold on the sheet it does not let go of the sheet but that little bit of movement affects the fit and doubles off the next blanket in pressure.when that is done put new stick on packings on all the plate cylinders so that the packing and the plate measure .15 above plate bearer height, then the blanket packed to .05 below blanket bearer height( allow for a bit of loss due to tensioning the blanket( .05 ). sorry if i had mentioned things you have already done. it's been a couple of years since i was on a heidelberg so check with the user manual.hope this helps .
regards johnyprint

 

The SM 52 does not require packing behind the plate. I do agree with that the final height of the blanket should be slighty under bearer. No more than .05mm.

 

Wild scenario ( happened to me once in Cyprus) !! Same problem on a 4-color 52 was caused by a loose cylinder. The screws that I found loose were the screws connecting the main body of the cylinder and the bearer on the drive side. Its worth a check

 

Cheers for that Mech will keep that in mind. Had a look at all the cam followers today and they all seem pretty solid. One thing i forgot to mention when i said about it printing smaller was that it seems to be worse down the DS.

 

You wouldnt by any chance be using poly plates are you?

 

No, not using poly plates.

 

GTO 52 4 Col Movement Problems

We seem to be experiencing similiar problems regarding movement between units , mainly on lighter stocks 100gsm-115gsm.We've been through and checked cam followers and grippers.The Problem tends to arise with jobs that have heavier inking on the drive side.