Akiyama 4/28 moray problems

We have an older Akiyama 4/28 that we are experencing problems with moray patterns comming and going on peoples faces. The pattern is not consistant from sheet to sheet, some sheets are fine and some get a pattern. I had the prep dept check our screen angles and they are on specs. The press runs with blk 1st down, cyan 2nd, mag 3rd, and yellow last. The Aki repairman was here yesterday and changed 2 cam followers on the transfer cyl. he checked all gripper settings and etc, and he can't explain why this problem is happening. At the time the moray happens, the magenta gives more to solids and backgrounds making colors seem redder. Anybody have any ideas or sugestions?

 

hi mate i used to get this when i ran one a couple of years ago. i never had it sorted but i always had a feeling it was the Swing Arm Grippers but as yours is three units in it may not be that. do your Sheets get Shagged at the grip or are the nice and clean with no creases etc?

 

gripper ends are clean, and we pertrimmed the paper for the gripper

 

have you taken a pull of 3 sheets and then 4 and checked if it is happening on every sheets. if its only happening every 3rd sheet its a imp cyl prob every 4th is transfer if its on every sheet but different pattern it may well be the swing arm. have you checked if your grppers have still got the platic tip on them and if the diamond tips are still diamond?

 

Am not a Komori man so can't comment on the press but also if it's every third sheet it could be the paper as they usually sheet in threes, sometimes you can see a ripple effect if you look at the paper closely or it could be a an out of square sheeter

 

thats right about sheets being sheeted in 3's so the best way to eliminate the paper is to use different types of paper on a test (off another pallet, differnet brands etc and see the results)

also does it give yout his problem on every stock, i seem to remember having a problem with european 115 and 130 am doing this as it tends not to be as bulky

BTW Notagooner its an akiyama not komori

 

Sounds a lot like interunit doubling...you've had cam followers checked/changed so it's down to grippers...either settings or transfer timings. Thinner or lighter stock will show it more since there's less tolerance. Does the double extend from grip to tail or just at back end of the sheet?

Here's some thoughts..

I can't see it being before the magenta impression, unless you're seeing doubling of the dot in the preceeding colours, so that narrows it to between magenta and yellow.

Try running plain sheets into the press, stop the press and just before the sheet transfers into the magenta impression hold the tail edge reasonably firmly, get an assistant to inch the press slowly. Do you get sheet release at transfer point? Well you shouldn't. If so you need to check grippers/cams for wear or poor setting.

Not being a grammar nazi here but it's moiré not moray

 

Hi, i used to run a 628 for many years and the only issue really was with the cam followers. You say the engineer replaced 2 of them but not 3??
Do you know why??

 

I agree with Stratos.

I've run Akiyamas for years and always when we've changed the followers out, we've changed them out on the entier cylinder to avoid any difficult to trace problems (later, you dont have to "remember" what got changed). I think there is a lot of pressure on those followers so even when they are greased regularly they tend to wear.

And if two are bad can the others be far behind?

Be sure to use a quality replacement part (INA) too. I've seen lesser parts wear prematurely, and no one wants to see that cam get damaged...

Also, check the swing gripper stop screw (drive side of bar) to be free of grime or paper dust.

Good luck!

 

Call me I worked for Akiyama for over 7 years.
And what was your technicians name? there aren't very many good ones for akiyama presses
909-945-7061
Your problem can be quite simple

 

Hey mate besides the machine this can also be caused by paper(dimensional stability). I had this problem but on a sorkz 2colour press. The paper i was using was being sheet at our factory noticed that after sheeting the paper wasnt as flat as the one we bought as sheets, hence during printing, the printing nip was different on each and every sheet. Before changing press settings try buy flat sheets from your supplier & see the result. Also check the tension of your blankets.

 

your transfer gippers need replced or adjusted. The pads are worn down. The sheet slips under blanket pressure thus causing your moray.

Rod (old school)

 

Akiyama 1989 model

i have problems in timing cam shaft. for every job i have to check the timing cam shaft any suggestions

 

moire

For good quality service call me 909-945-7061

Only changed 2 cam followers what a yahoo who was this tech?

could be more camfollowers
gripper tips
infeed
transfer points
end play
screen angles
paper

 

You lost the taper pin. the bolts alone have too much stress and cant hold tight enough it slips everytime the feeder is engaged.
OK 1 freebie
need service 1-909-945-7061

 

A loose blanket will do it as well. Tighten them to specs with a torque-wrench.