Heidleberg Gtov Head Stop Problem

[western411]

When running at speeds over 4000 IPH the head stops fail to hold off when the press missfeeds or the stop feed button is pushed. The head stops clang against the feed board and act like they are trying to feed paper until the press comes off impression. At speeds below 3900 the problem dose not occur until we slow to crawl speed. We can run fine at faster speeds but must quickly slow the press down below 3900 if we hear it misfeed and start to shut down. We have been told the solenoid may be setup for European but hate start buying parts for might be. We are running a free standing transformer pushing 234 volts. The internal press transfer has the pigtails set for 240. I am looking some anyone who has had this problem.

 

[GazKL440]

I have had a GTOZ do a similar thing, it would misfeed and not go off impression, and register would go further and further away as you sped it up (which was just great when you set a job up at low speed then cranked it up to run it off). That turned out to be the misfed sheet dam solenoid playing up, sticking slightly and throwing out the timing of the head lay enough to upset register... Are you running factory spec oil or just whatever the production manager dug up from the back of the factory? Sometimes heavier oil can slow down the swing arm and cause a bit of clunking especially on cold starts..

Hope this helps

 

[rbailleu]

does the swing gripper still grab the sheet that should be left on the feed board during a misfeed?

does the swing gripper always flip up at high speed and only when feeding and low speed?

the magnet should give you a positive snap when it kicks on during a shut down.

 

[western411]

does the swing gripper still grab the sheet that should be left on the feed board during a misfeed? Yes, but only because the head stops flips up. this is a real problem with a double sheet on heavier stocks. We sit and listen during production and if if hear the sheet release after we have heard the system start to sequence a shut down we have to hit the emergency stop

does the swing gripper always flip up at high speed and only when feeding and low speed? About 80% of the time the head stop will flip on a miss feed. Some times it will hold for a sheet or and then flip untill the press shuts off

the magnet should give you a positive snap when it kicks on during a shut down. Yes

 

[rbailleu]

you have something out of adjustment under the feed board. I would guess you have a bearing out on one of the cams. there is little stop that holds up a metal peice that the cam for the swing grippers rides on. if that is grabbing the sheet still and the head stops are moving then it could be an adjustment in the linkage of the magnet. if the magnet is working, it should be pulling the stop for the swing gripper cam and the head stops into the right spot. if the head stops work correctly sometimes, but the grippers always grab then the gripper stop linkage is worse than the head stop linkage. I forget if there is a separate adjustment. there is a lot of stuff moving under the feed board and it s all on the drive side so be careful.


the swing gripper should be held open if the head stop is down. it wont grab a misfed sheet if adjusted properly. there is an adjustment screw on the head stop shaft above the feed board, but that just adjusts the timing of the head stop to the swing gripper. its not a large adjustment.

 

[western411]

We have a brand new swing gripper and complete cam assembly ($11,000) thanks to a an idler roller that dropped off the DDS water roller into the press. turns out the idler roller dose not really need to even be in the press. Ours is now embedded in the wall.

The grippers only engage if the head stops swing out of the way. This is what our problem is. The head stop clutch is engaging when it should not, allowing for a double sheet to pass or in the case of no sheet feeds it just clanks against the housing. We have checked the setting you mentioned on the cam block and dont see anything our of wack. We greased the heads stop arm and got alot of oil under the assembly. We are wondering if the arm is binding as the clutch is engaging causing the magnent to fail to pull ( ie it cant pull hard enough and losses magnetic contact). We are since flooding the crap out of the arm with lube the problem has sort of gone away. We think as the systems is heating up over time it may be binding on the arm as it is pulling off causing it to fail. We are also wonding if there is a spring tension that could be acting against the magnet

 

[rbailleu]

I dont remember any tension against the magnet. I think there is a small spring to return it to off easily. as I remember the magnet is mounted upside down and pulls up to shut off. so that with no power to it it will just alway runs. the missing sheet should still shut off the impression. correctly. I may be that you have a compound issue. the head stop should work continuously if you simply unplug the magnet. I would try unplugging the magnet and checking that the missing sheet is working correctly. its that little piston thing underneath the feeder. a piston slides out when a sheet does not feed down the feed board. take it apart and clean it. no grease or oil.

I know this does not solve the head stop issue but should not affect printing. and unplugging the magnet will tell you if the thing is adjusted correctly to run at all speeds.

ps I hate the dds system. it is the major reason we have a sm52 today.

 

[western411]

The head stop run 80% of the time at speeds over 3900 IPH when the press in on impression and sometimes continue to bounce until the press shuts down or in some case holds a rotation then bounces then holds until the press shuts down. We can make this stop if we slow the press down below 3900 iph as it is feeding out the sheets in transit as it is shutting down. When we hear it start to shut down due to a missed pickup or double, we jump up and slow the speed down to 3000 iph and we are OK. It generally only does it when the press in on impression.

 

[western411]

Thanks to all who posted information

We downloaded the information from the US Patient office which showed how everything worked. We went in and put WD 40 followed by oil on every moving part associated with the head stops and the timing pawl device. For the first time in 5 years it is not giving us trouble. We think it may have been a gummed linkage causing a delay. It could or might explain why it worked OK at slower speeds. Time will tell, we will see. Maybe the press just saw me walk up with a cold beer and the big fixit hamme

 

[rbailleu]

well congrats. sorry I did not help much, but I am glad its working a large hammer next to any machine is a good thing. especially computers.