Kompac III on Heidelberg GTO 46 scumming problem (pics in post)

Our GTO is an older unit but is still our workhorse, but can't run screens anymore, and ink builds up on sides and edge of plate. Kompac forms are new and we typically run 1/8 strip on water (distilled) unit. Thanks!

Fountain solution - Formula 300
Plates - AB Dick Elite (Mark Andy) / Fuji
Ink - SunChemical

 

There are several things that you can look at, but it looks that you're plate isn't staying wet enough. Maybe it's as simple as opening the nip on the Kompac unit to allow more water in the system. If that's not an option, if your stripes are set correctly, maybe altering your fountain solution could help. I'm not familiar with Formula 300, but our solutions that we use are all 2 part. The fountain concentrate and the additive (alcohol sub). If everything was set correctly, I would consider upping the substitute in our mix to see if I could get our water wetter.

Other things to look at:
Make sure there is no end play with the form rollers so they aren't oscillating on the plate.
If you haven't done so, your ink forms to oscillator stripes s/b the same or slightly bigger than the stripes to the plate. You don't want the plate to drive the rollers. We set ours at 4mm. We typically set our forms to the plate like this... Red - 1 to 2 mm, White - 2 mm, Blue - 3mm, Yellow - 3mm and the water around 4mm. Sometimes we'll just set the water form to the point of starting to feel the bump when the cylinder gap comes around on the stripe adjustment. Ours will usually have a slight bump or bounce.

I imagine you've looked at all of these things already, but thought I'd put it out there just incase. Hopefully, some others will have some ideas to get you back on track. You're right, GTOs are work horses and the Kompac units are generally pretty friendly to use... it would be nice if they had speed control, but then I guess they wouldn't be so simple.

 

I have a gto 52 w/kompac as well, having the same problem, adjusting the oscillator pressure to form helped, I am going to replace the roller to see if it
eliminates the problem entirely, though the roller is fairly new seems the internal parts are worn...

 

You may want to check stability of the inking forms in their three point holding of the journal boxes. If the ink forms are sloppy, so too will the ink/water balance.

 

How can you check this? If journals move/bump around i presume. What can you do to remedy the situation?

 

The bearing for the roller should be snug in the holding that Junker describes. You can check that by simply trying to move the roller while it is in place by prying up and down on the journal of the roller. If the points/posts are worn then the bearing will be able to be moved around. Overtime, those points/posts can develop flat spots on them if there was a bearing that was turning. They're kind of a pain to get to, but those posts can be replaced and/or sometimes be turned so that the flat spot isn't touching the bearing. I've seen our mechanics do it, but I apologize that I don't have the details of how it's done.

 

Ancient Chinese secret, BD! On the serious side of things, you're right, the set screws that lock up the eccentric pin (that being the one with screwdriver slot in old version, 4mm Allen socket in new version) can be difficult to get to, especially on the 2d and 3rd forms. Older machines have the set screw under the colored cap, newer machines on the perimeter of the journal box adjacent to the moveable pin. If the stationary pin is worn so that the eccentric doesn't take up the movement, removal is necessary.

 

You at Deluxe check in Shoreview, BD?

 

I am with Deluxe check, but located in Missouri.

 

Just curious, thanks.

 

Is there a oscillator roller on your komac unit? I don't see one. Varn added this over the years to help with this problem. First they had it on the hard roller. Later was switched to ride on the soft form. I've never run one on a GTO but have run them for years on other machines.

 

On the Kompac III, it's underneath and touches the soft form.

 

Ah good to know thanks! As mentioned you can open the nip a hair. I used to run a 4 oz glycol based Varn (pink) solution. Sort of like the old Varn Super lene. Added 2 oz's of mega plate etch and used 22 oz distilled H20 per kompac bottle at problem shops. My magic mix. Never liked Sun ink much always Spinks acrylic oil base. Good luck hope you find a solution!

 

We used to use Sun Chemical ink in our facility and loved it, but our corporation got in bed with another vendor and we've had nothing but headaches since. I'm not here to bash that vendor, but we'd go back to Sun in a heartbeat if they'd let us!

 

Hi just simple remove complete unit from machine keep on table and reset and install..... see if any worn out parts ....normally there will not be much problems unless wear and tear r there.... remove clean and fix that should work....