Pizza Wheels on 3880


#1

Using a Tiff that has a broad area of black on a 3880. On larger prints where more ink gets laid down I am experiencing Pizza Wheels in the dark sections of the print. On a 10x15 the artifact kinda disappears as the print dries on Jon Cone Type 5, but the artifact remains on a full sized 13x19 on Jon Cone Type 5.

Using Canson Platine Fibre Rag the effects are worse, especially the larger print. Again this is in the areas of dark shadows and mucho black.

 

My platin gap is set to normal, and in the past I have only had to set the paper thickness to wide from normal when printing 17x22. Might a higher platin gap for a thicker paper alleviate the Pizza Wheeling that accompanies this problem Tiff?

BTW this image was shot around 11 AM in middle summer so the contrast is kinda hot/high. For extra understanding image capture is via a Leica Monochrom which pairs wonderfully with Piezography.

Any help in dealing with the Pizza Wheeling is greatly appreciated. Thanks in advance.

 

Cal


#2

I worked out a solution and Keith Schreiber wrote it up. It’s on his blog here: https://jkschreiber.wordpress.com/2016/08/08/how-to-disable-star-wheels-on-an-epson-3880/

 

It pertains to dig negs but will work just fine with Piezo as well.

 

-Walker


#3

I used a disposable hearing protection ear bud to set the switch. This allows me to replace the side cover. I found by probing with a take-out chop stick that very little pressure is required to set the required switch. Having the printer on with the front load door open stopped the initializing process that happens upon initial turn on. When the switch gets activated the process continues and the request to close the door goes away.

I found that the “optional” step at the end with the hinged guides to be mandatory because these two tabs consistently caught the front edge of my paper to begin trying to effectively fold my print. Also there grew a possibility of scuffing a wet print, especially as the print counterlevered over the step created by the front load door and the exit paper tray. A small spacer (I used a folded subway map) was required to prevent this counterlevering to develop into a buckle in the paper that might further lead to a head strike. In the future I might create a more elegant spacer out of museum board to remove this step in the exit path.

Also I decided to remove the front load paper guide because on my printer the suggested ramp did not work and I experienced a head strike on the trailing right side of the print as a result of the ramp lifting the paper.

A pair of lightweight flush wire cutters allowed me to nibble the right front paper guide away. A band aid covers the wound I created. LOL.

For me imposed wide margins are no big deal: I like the presentation.

Thanks for solving the problem.

Cal


#4

Update: I experience difficulties towards the tail of my printing with head strikes. It seems ink loading caused bowing and buckles that would eventually lead to headstikes that compoundedly would unregister my paper towards the end of my print.

I developed a workaround by printing on half of a larger sheet by manipulating a custom paper size in Print Tool. This in turn allowed me to minimize my margins because I used the remaining half of the sheet as a very long tail.

After drying I print the unused side and basically print two images separately allowing for discreet and separate blending of the three curves in Print Tool.

I wonder if this technic might be useful to others that can front load to avoid Pizza Wheels. The idea being that an extra long tail can defeat the requirement for extra large borders.

Cal


#5

Does anyone have ideas about how to solve the same star-wheel problem with Epson 4900 printers? Thanks


#6

Hey Pradip. It requires a “leader” page taped to the film and then front-loaded. The instructions for this are in >Piezography>Documentation>Instructions

best,

Walker


#7

Thanks Walker, for this suggestion and all the other help you have given me as I slowly (my fault) get up to speed with Piezo-DN.

I tried the method described in >Piezography>Documentation>Instructions

and it certainly made a difference! But I am still seeing* (albeit finer) star wheel dots in the latter half of the sheet (*after heat drying + 1 hour). I feel sure they will show up on a pt-pd print. I have tried the following so far:

  • I have adjusted the platten gap, first to ‘narrow’. Then I did a thickness test with Pictorico film and fine tuned the gap to #1.

  • attached leader/trail sheet that is at least 50% longer than the Pictorico UP OHP film

  • have printed at the very bottom of the sheet, as well as the top

  • have even printed an 8x10" target in the middle of a 13x19 P UP OHP sheet with a leader

  • have rotated the target image by 90° just to be sure

and there is no difference - the star wheel tracks keep showing up in the densities.

Has anyone else had any experience with a 4900 doing this, and if so, are there any solutions? Both Walker and Keith have presented whats seems a great solution and instructions for resolving this problem with 3800 printers. I have look around for a similar hack with the 4900 but have not found one as yet.

Thanks in advance for any suggestions / guidance!

Excuse the rough iPhone photograph, but I hope it sufficiently illustrates the problem:


#8

The star wheels on the Epson 4900 printer are at the back of the print-load. This means that the “leader” sheets needs to hang down making the film bend away from the the wheels to keep them un-marked.

So make sure that the paper in the back is handing down. Placing the printer’s back flush to the edge of a table can help with this.

best,
Walker


#9

Hi Walker - thanks for this suggestion. I have the leader paper hang out the back over a table edge, still getting tracks. But after your pointer about the location of the star wheels, I ran another sheet (leader + Pictorico) through and watched the guide wheels with a flashlight. The wheels, what looks like two or three sets of them, are at the front, near the exit point of the printout, and downstream of the printer head. The bars that hold the tracking wheels drop down soon after the sheet begins to go past the printer head track. I have tried attaching a front sheet too, a ‘leader’ leader, in the hope that the weight of the leading sheet would hold the film down and away from the star wheels, but that too does not work and leaves a mark. Each star wheel is on a spring-spindle, so pressure applies regardless of distance from the exit rollers.

I am now deep into the service manual and trying to figure out how to disable the drop-down of the whole tracking bar, or even if/how I can actually remove the star wheels.

I’d welcome any other pointers.

 


#10

I think I have everything working! Walker, thanks again - the trailer sheet is vital to avoiding star wheel tracks but with a number of other steps with the 4900, which I describe below.

The star wheel bars (two of them) drop down near the exit point of the print, when a sensor located in the front-right area, just before (towards the print head) the bars, senses paper that is curling upwards. I tested this out while a sheet was printing, by sliding in a long scrap of paper about 5 mm above the output bed in the vicinity of the sensor, and sure enough, the star wheel bars dropped down and remained down for the rest of the print run.

Removing the star wheels is easy, if you are prepared to

a) remove the upper front cover (quite easy)

b) quite physically flip the star wheel tracks into the active, down position,

c) and then with a very thin and long pair of needle nose pliers gently coax each pair of wheels out. They come off quite early, and are held in place by a single spring-spindle.

I did this to just one pair of wheels, and then, just to be sure, managed to put it back into position. It takes some patience and dexterity with two pliers, but can be done.

Having tried this, I wondered if there was an easier and less drastic solution.

So, back to Walker’s plan, and with the following extra steps, presto! no track marks, and a much easier solution:

  1. In the Epson Printer Utility (v4), access Epson LFP remote Panel 2

  2. Select the printer (4900 in my case) and then Custom Paper Setup

  3. Set Reference Media Type to Premium Glossy Photo Paper(170); Paper Thickness to 1 (x.1mm); Platen Gap to Narrow and most importantly, Drying Time/Print Head Pass to somewhere between 10 and 30 (0.1 secs). I tried various settings and 20 (2 seconds) seems to work well.

Give this group of settings a custom name, Save… and Activate it. You should see the preset number appear on the printer’s console.

  1. For each sheet of Pictorico UP OHP, I am taping, as per Walker’s guidelines, a trailer sheet about 150% longer than the transparency sheet to the P UP OHP. Be sure to have exactly the same width for all pieces and tape edge to edge securely and cleanly.

That’s it. The pauses between each head pass seems to give the film just enough time to loose its upward curl by the time it gets to the sensor, and the star wheel bar does not drop down. I have done this with about 10 sheets of film with no stellar descent.

So, Occam’s razor - either that, or I have been a bit of a dolt. Sorry to have taken up Walker’s (and other’s who may have considered responding) time!

I am thrilled with the output from the default Piezo DN PtPd_default curves. I hope to print some of these negs in the next few days, and then, if necessary, get into fine-tuning the curves. Thanks!

 


#11

Platinum neg printers are a willy and inventive bunch. I will work this up into the instructions and credit you Pradip.

all the best!
Walker