GTO52-P-2 Pincer Gripper

[Lynden]

Good day everyone, we had worn needle bearing on the holder on the pincer bearings which we replaced but I had only marked the Operator side as I haven't had any experience on this removal and after removal I noticed that there are two separate gears and I had only marked one. Now I am having some difficulty in getting back my timing as the pincer grippers are tearing the paper on the transfer to the Impression cylinder... please advise on the best way to get them back in line. Thanks

 

[junker1984]

Simply marking the OS gear wouldn't do you any good if you didn't have a reference point of when to mesh the gears. This is really not something that can be relayed via a forum. The way you went about this, as you said with no experience, just put you in a very poor position. It will be truly hit/miss trying to find the proper gear mesh. Best I can tell you, as you're looking at the bar from the OS, at say, 2:00 position, the fixed gripper would be pointing about 2:30 and the spring loaded gripper would be open to the point you can just get your pointer finger in up to the end of your fingernail, or a bit less. As I type this, I'm thinking to myself that maybe you have the bar in proper mesh, as you infer the transfer at pick up from the storage drum satisfies you, but there's something else wrong. I'm also thinking I never should have entered into this conversation.

 

[Lynden]

Thanks for your advice as well as your observation. Please understand in Belize, training and certified individual are many times non existent so we having 30 to 40 years of success dealing with Heidelberg presses and undertake tasks that require professional advice. This gripper is not that complicated but just the setting is. We have gotten the degree gauge to set the exact degree to check gripper etc. but we didn't get the pointer to use along as a part of the process. I am very appreciative of advice and guidance provided by the fortunate few that are trained. Thanks as always.

 

[CHOCK]

Dear Sir:
Good day
What is the problem with his machine Heidelberg ?

 

[Lynden]

Morning Sir, we had taken out the pincer gripper from our GTO52-2-P as it was dropping the paper in perfecting only as on straight the pressman had applied some urethane to accommodate the worn needle bearings. we have ordered but we had too many orders requiring the perfecting capabilities so we took it out and put in temporary bushings until the bearing arrives. After re-assembling we have taken a long time to get a close transfer but its not accurate,it's off and I really would like to know a way as we will have to do it again after the parts arrive. What is the correct position to set the pincer gripper on the segment gear? our machine serial is #716432. Thanks, any advice will be so appreciated.

 

[CHOCK]

Hi sir
You need to know very well the time transfer for the Assembly Grippers.
Otherwise you will problems.
Is Matter carefully .

 

[junker1984]

As I'd mentioned, Lynden, there is no procedure in any book that tells you anything about when to engage the pinion to the rack. If you don't properly mark it prior to removal, you must do it trial and error. Even at that, it's not too difficult. I would, however, not use press power in trial and error. Turn by hand. And experiment with positioning in straight print.

 

[contractor]

Hi Lynden - above are some pics of what your grippers should look like. The fixed gripper (below) is roughly in line with the centre of the cylinder at the 2 o'clock position in straight printing. In this spot you should get your index finger just in as junker said. If your out one tooth in either gear this reference point will be a long way out. Keep in mind under the gripper mounting blocks has shims and they were put back in undamaged and locating pins were put back. Not sure how far you dismantled the bar but if you took the grippers off then you have to set the fixed gripper height and pretensions then set degree timings. To do this you need the correct gauges and a service manual. This job is not a remove then rebolt simple job it has procedures and you need to be experienced or you will have problems.
Hope this helps you

 

[mantman]

I am sorry but i cant hold my tongue -or fingers- "i see dead ink"

 

[junker1984]

Ii just couldn't bring myself to say anything.

 

[exheidmech]

When installing the pincer bar, there should be a gap of approx 9mm between the spring loaded gripper and fixed gripper. this is assuming that the pincer bar was pinned in the reversing cylinder. If the gripper bar was not pinned in the reversing cylinder all bets are off and you are going to have to do the trial and error method. As already stated a few times in this post, this type of work should be performed only by those trained to do so. Perfector is very cost sensitive area of the machine and one small error can cost tens of thousands of dollars even on a GTO.

 

[PARASURAMAN]

Hi I have changed many times hope you should crank the press and do trial and error but if it's not properly done note you're going into big trouble ending up paying more the cost of what you tried to save... and you will realize the pain.... just call a tech and fix it this is not to be done by a person who don't knows anything about the trouble....good luck

 

[Lynden]

We have successfully installed it even though we know that to get a perfect fix we would need some professional tools. We have a service manual that was bought a few years ago and we followed it as much as possible to get it close as possible before reaming out a new tapered pin hole to get it accurately. We would like to see some photos that show the pincer grippers two ends at the segment gear if anyone can help us so that we can check on settings. Thanks always.

 

[junker1984]

With the many very close tolerances that must be achieved, pictures will do you absolutely no good, Lynden.

 

[Lynden]

Afternoon all, after getting the press working for a the last two weeks we noticed that the Cam Follower that controls the Segment Gear is worn and we will need to change. Since I jumped the gun the last time to undertake the removal of the Pincer bar I really would like advice on this to prevent problems.

 

[junker1984]

First, you’ll have to remove pincer bar, be sure to mark gear mesh and position of removal, and do not mix up shim packs under pillow blocks. Use slide hammer to extract pins from segment gears, then remove fastening bolts being wary of any shimming on removal of gears. Turn drum to access removable section, remove bolts and pull out center section. Remove torsion spring. Pull pins and bolts from segment with bad follower. Actually, it would be very wise to replace both followers. Hopefully you have access to a hydraulic press, pounding on followers for extraction and insertion is not wise. There is more to doing this than I’ve typed out, but if you follow these basic points you’ll get it.