mistubishi grippers falling apart!!

[Mitsuboss]

We have a 2 year old Mitsubishi Diamond series 6/c with coater (40")...the spring clips on the delivery grippers started warping and breaking about 6 months into production....
Mitsubishi stepped up to the plate and replaced all the delivery gripper bars as an answer to the problem....Well 4 months into the new set it's happening again...Matter of time before metal flies off and smashes the coating cylinder, or worse.
Again, Mitsu. is replacing all the delivery grippers (we are under warranty).
Just wondering if any of you folks out there are having similar problems, or are we the lucky ones?

 

[GazKL440]

I have had a gripper pad on the tumbler in a Rekord come astray and smash the second unit pretty badly (1 impression cylinder, 2 blanket and 1 plate cylinder scarred up badly) but that was after it had been round the clock several times... Sounds like a bad batch or 2 of delivery grippers or maybe too heavy a return spring... Should not happen on a new press at all!! Hopefully they sort it out for you and compensate for down time..

 

[k_graham]

I have had a gripper pad on the tumbler in a Rekord come astray and smash the second unit pretty badly (1 impression cylinder, 2 blanket and 1 plate cylinder scarred up badly) but that was after it had been round the clock several times...

Check that your insurance covers for machinery breakdown. Our refurbished Heidelberg DI had the motor and and driver board go under warranty, Presstek replaced the entire press due to other issues but I added this insurance that should cover me for such an ocurance after warranty in addition to the jobs sent out, though with a 2000.00 deductible. I can afford 2,000 not 200,000.00 repair bill. In addition we added a whole shop surge suppressor, supposed to direct surges to ground, another $300.00 of Ebay plus Electricians time to install.

Ken

 

[rbailleu]

does this press have an ir dryer on it. I heard about a opperator running a dryer at 100% for 10 hours straight and warping a couple bars on a sm102

 

[bharatmacho]

hi mitsu,

your problem with the breakiing of delivery gripper springs is caused due to the spring tension.
i think you had a drier with IR lamp and heater as the grippers passes the heater several times the metallurgical properties changes gradually and they fails.

 

[Mlpklr]

Springs breaking is 99% of the time due to lack of lubrication. The spring coils around a shaft, over the gripper tip, and coils around the shaft on the opposite side of the gripper. Every time the gripper accuates the spring rotates on the shaft it's coiled around. Without weekly spray lubrication it's metal on metal contact which inevitably wears both the shaft and the spring. On the "S" model machines it's spring on shaft contact, on "LS or LX" machines there are bushings between the spring and shaft. Without adequate lubrication the springs wear into the bushings of the LS and LX models eventually causing the same problem, but the bushings are meant to take the wear instead of the shaft. Each bushing is about $2.00 where the shaft could be upwards of a $1,000 depending on type.

Dryer temperature could be a contributing factor, but not because of changing the "metallurgical properties", but because the spray lubrication being used does not withstand the temperatures the dryers being run at.

 

[Mlpklr]

KANO Laboratories makes a spray lubricant called Penephite which contains graphite. When the penetrating lubricant disipates it leaves a graphite residue as a lubricant. It works well in reducing wear when used per the press manufacturers recommended lubrication frequency; given the dryer's not running on 100% all week.