Digital BW, The Print

To follow up on keeping a printer clog free:

I live in Colorado which as you might be able to tell from the fires, 
is in a multi-year drought with low humidity and high temperatures. We 
have had perhaps less than 6 inches(?) of rain this year.

I've had problems with two 1160's before with the old piezo inks and 
MIS inks, and when I bought an 1280 in January I decided to monitor 
closely environment and performance of printer. While I have had few 
banding issues, I have had more than my share of clogs. I decided to 
experiment with frequency of use and humidity/temperature.

The following must be labeled "subjective" as I did not keep an 
extensive printer diary, writing down how the printer responded under 
what environment twice a day for seven months. It is from 
"impression".

To "use" the printer, I would turn it on and run a MIS 6 color purge 
print in draft mode on plain paper, which takes about 30 seconds and 
uses not much ink, probably much less than a cleaning cycle. I follow 
the print with a nozzle check and up to two cleaning cycles before I 
put a solution of 40% ethanol to distilled water on parking pad.

In January the humidity ranges from just under 20% to 35 %RH. I added 
an humidifier to the room and adjusted it with two seperate gauges, 
one near printer and one monitoring humidity and temp across the room.

In June the humidity rises from about 35%RH to as much as 60%RH (for 
short periods when we got a few drops of rain or with a sudden 
formation of clouds over the mountains). When needed I turned the 
humidifier on for a few hours to a day which usually restored the 
level back up above 40%RH.

I used VM inks in self-filled vacuum carts until July, when I switched 
to a CFS.

I discovered I had to do far fewer cleaning cycles to get a clear 
nozzle check when I did the following:

1) Kept humidity above 35%RH, 40-45%RH was much better.

2) Printed out the purge pattern in draft mode every 12 hours. 24 hour 
frequency subjectively seemed to me to waste more ink in cleaning 
cycles than in printing purge patterns. I would guess that I averaged 
about 4-5 cleaning cycles per week and never a serious clog (excepting 
on occasion when I changed carts), and only about 4 applications on 
the parking pad since January. I only missed the 12 hour "use" two or 
three times, and I almost always had to do two cleanings to clear 
printer with the next "use" 24 hours later.

3) There seems to be a  (weaker?) secondary effect of temperature on 
nozzles. With an air conditioner, keeping temperature at 68-72 degrees 
F subjectively seemed to give a better chance of a good nozzle check. 
When the temperature was above 77 degrees, it seemed to me more likely 
to get a partial nozzle check.

So far the CFS is working at least as well as the carts did, after I 
removed 20cc of ink from bottom of cart, each chamber, per MIS 
instructions on recovering a "foamy" air filled CFS. Well, my ink 
wasn't really foamy, but it seems to have helped a bit anyway. But 
then I had trouble with getting the chips recognised and had to remove 
and re-install the CFS about four times. Most people, on a first 
install should not have this trouble I am assuming.
Jim H.