Thread: setting ink keys

some of the ducts have sticking keys and are uneven
Can any one tell me best way to set the keys On a 526
Thanks

Set the unit ink sweep to 50 &turn off your color control console
make sure none of the units are activated for use..
Go to the problematic unit,and open the door in front of the ink fountain,it should have one knob,once opened follow these steps
let press idle
adjust ink servo motor ...to close go clockwise...
To open servo keys go counter clock
set the individual key,or set all keys on that particular unit to a fine tint.
Try to get a fine tint all across the ink fountain ball/roller
do this especially for jobs that have very little ink coverage.
Never try to reset ink keys with unit selected....
Return ink sweep to where you usually run it....

Originally Posted by Mr. Litho

Se
adjust ink servo motor ...to close go clockwise...
To open servo keys go counter clock

Never try to reset ink keys with unit selected....

Just a heads up... the direction of rotation depends on the year of manufacture. Later models work the opposite (in my view the 'right' way).

If you accidently leave the unit selected you''ll get the flashing led of doom on the PQC. Hit lock then unlock for the key affected and the led should clear.

Originally Posted by Mr. Litho

Set the unit ink sweep to 50 &turn off your color control console
make sure none of the units are activated for use..
Go to the problematic unit,and open the door in front of the ink fountain,it should have one knob,once opened follow these steps
let press idle
adjust ink servo motor ...to close go clockwise...
To open servo keys go counter clock
set the individual key,or set all keys on that particular unit to a fine tint.
Try to get a fine tint all across the ink fountain ball/roller
do this especially for jobs that have very little ink coverage.
Never try to reset ink keys with unit selected....
Return ink sweep to where you usually run it....

Also, if zero setting the unit, start in the middle of the fountain and work you way out to the ends.

Originally Posted by Lignum

Also, if zero setting the unit, start in the middle of the fountain and work you way out to the ends.

What's the theory behind this?

I can see why you'd do that when working with a traditional flexible blade, but what's the benefit when applied to individual segmented keys?

Originally Posted by RichardK

What's the theory behind this?

I can see why you'd do that when working with a traditional flexible blade, but what's the benefit when applied to individual segmented keys?

The segmented keys react the same way as a traditional blade. The keys may be segmented, but still have the same kind of tension on the sides of the keys that hold them in place. Using the center keys as the baseline, you can tell when you have zero set the outer keys too far. It gives a truer zero set than working from the outside, in.

Sounds logical. Just never heard of it - ya loins somtin new every day.

Just thinking about this again.

Surely the keys are designed to slide against one another? Are you saying that if a key, say number 15 moves, then the 'tension' exerted by it on keys either side of it may cause them to shift position?

How can that happen when the micromotor holds the key in place via a lead screw?

Anyone else aware of this MO?

On the earlier models, with the lever mechanism that shifts the bearing/eccentric that presses against the key, the key is pushed toward the ball by the motor but relies on the spring in the center of the key to pull the key back from the ball. Thus if a key is sticking and the spring does not pull the key back, moving a key next to the sticking one can cause it to become unstuck and move back away from the ball.

This can cause great consternation when you move one key and the adjacent key moves as well. The solution is to remove the keys, clean them of dried ink and bed them back in place using a mixture of machine oil and grease.

You can determine if a key is sticking by backing the hinged fountain away from the ball, opening the key to about 20% and using a screwdriver as a lever, move the key slightly toward the ball. If it does not return, it is sticking and needs to be cleaned and lubricated.

When replacing the keys, start at the outer ends and tap each key toward the outside of the fountain with a small plastic or hardwood mallet. Getting the last key in is the trick. I do it by lifting the back of the three center keys and use screwdrivers to carefully pry the outside keys away from center while gently tapping the center key in until it seats. If you are unsure, leave this job for someone with experience. I have seen many cases where the keys were damaged by attempting to force them in.

An alternate method is to remove one of the cheeks and loosen the socket head screws holding the dead key to the fountain. (Loosen the dead key with the two adjusting nuts.) Turn the two adjustment screws to allow the dead key to move away from center. Carefully count the number of flats (six per turn) so the dead key can be returned to its original position. If keys are still sticking, first tighten firmly to squeeze excess lubricant from between the keys, then back off the two adjustment screws to the point where none of the keys stick.

As each key is cleaned, it may be helpful to de-burr the edges of the key with a very fine stone or emery cloth. After re-assembly, lock the odd numbered keys on the console. Perform several full and zero sets then do the same with the even numbered keys. This will help seat the keys.

Extremely familiar with this procedure. One thing to keep in mind is that a key that it too tight towards the center of the fountain will not allow the whole fountain to be set properly. The absolute, correct way to go about it is taking every key out, one by one. resetting the potentiometer range to 2.5mm, hone every slide with a stone and fine oil and re-install. Although, I doubt that you need to go through all of this. My favorite color to use is a purple with about a 95% transparent base. Remove the foil/tray from fountain. Close fountain on both sides with the knurled fountain screws. Apply a film somewhere between 2-4mm against ball roller all the way across fountain. Lock the drum roller clutch into place and start to turn the drum roller without ducting of course. Watch the drum roller at all key locations. If you have one or two that are showing shiny chrome then they must be backed off FIRST before going any further. A lot of times someone screwed with the settings with a dirty fountain or lack of knowledge and closed one key too tight, which is not allowing the other keys to seat correctly. On the outer edges of your fountain next to the knurled locking screws there should be a 19mm nut with either a 4 or 5mm adjustment screw in the center. Most of the time this is all that has to be adjusted after relaxing your tight ink slide or slides. You can bring the whole fountain in and out with these adjustment screws but first you have to get your slides even. In my opinion, the dilluted purple is the best color for this but others may have their favorites.Hope this helps. P.S. MAKE SURE THAT EVERY KEY FRONT IS SPOTLESS AND THE FOUNTAIN GUARDS ALSO. YOU WILL NEVER ACURATELY 0-SET WITH A DIRTY FOUNTAIN!!!!!!!!!!!!!!!!!!!!!!!!!!!!