Hi, Just wanted to add an update on my situation. After a long hiatus I resuscitated my trusty 7800 and installed a fresh supply of
UltraMax II Pigment Ink. That is a whole story in and of itself, but after finally clearing all the clogged nozzles I printed out a new profile target chart.
I waited overnight for the chart to dry and started scanning it the next day. It started out fine but as I was at the bottom if the first page I noticed that there was some burnishing on the surface of the paper. As I continued on the second page a scratch appeared in the center of the page. As I continued the scratching got worse and quickly ruined the target. Arrrg...
After a thorough investigation I came to the following conclusion. There is a design problem with the ruler and table that can easily lead to excess friction between the ruler and target as you scan the target. Also that there is a workaround that can be used.
First on the bottom of the clear plastic nose of the ruler there are several circular indentations that I presume are left over from the molding process. On one of these in particular there were some very slight sharp edges that were big enough to start scratching the page. I could also feel several other rough spots on front edge. I think that those were nicks caused by the ruler not being firmly secured in the carrying case. The fix to both of these was using some 600 grit sandpaper on a flat block to gently polish the bottom edge. In the future I am going to wrap the ruler in a clean micro-fiber cloth when storing in the case.
Next to test my fix I put a undamaged target page in the table and started to gently move the ruler back and forth. Sure enough the nose stopped scratching but after several forward and back movements there was severe abrasion of several columns in the chart. The bottom of the heal of the ruler was smudged with ink (see attach picture). Now I'm getting pretty discouraged.
By using a steel ruler (verified to be straight with with precision straight edge) I found the following. The bottom of the heal of the ruler is dead straight. However, there is a bulge in the center of the my table of about .003" or .004" right at the joint where the table folds for storage. This is sufficient to cause extra friction to burnish surface of the target print when scanning the target by sliding the ruler. When scanning I am moving the ruler by by holding it at each end.
However, when I was testing to see if fixed the first problem I was using one hand in the center of the ruler to slide it back and forth. And therefore pressing the ruler directly onto the bulge in the table. This immediately started to abrade the surface of the print and as soon as there was pigment particles trapped between the ruler and paper it acted like rubbing compound.
In the meantime I have figured out a workaround so that I can generate the new profiles in need to start using my printer. I had to get the heal of the ruler up off of the print while scanning. It also needed to be done in a way that allows for different paper thicknesses.
The solution was simple enough. I cut 1/2" x 11" strips of paper and started stacking them on the edge of the table. It ended up taking 3 strips on each side to raise the center of the ruler high enough to clear the bulge in the table. This allow me to scan my first target and make my first profile. The initial prints of the
DigitalDog tip and tricks gamut test files look very good even though my initial target contained only 400 patches.
I hope that will be useful and will help someone else.
I contacted X-rite support and they want me to send the whole system back to them for evaluation. I plan to do that after I get all the necessary profiles built. They also suggested that I wait at least 24 hours before trying to scan the target. I will try that also but I suspect that the bulge in the table is just to big and I will see damage to the print unless I have the shims in place. Just a note that with the shims in place I scanned the 400 patch target only 3 hours after it was printed with no damage to the print.
-louie