Why can’t I just let this go?
It occurred to me that all I needed to do was weigh a cartridge just before an auto clean and then again just after.  That is what I have now done.

First I should clear up one minor point.  Previously I mentioned that the Pro9000 uses 1.1g (A-ch) and 0.8g (B-ch) for the 120 hour purge.  Channel A and channel B represent the 2 sides of the printhead.  The reason channel A and B purge different amounts is that one side supports 5 colours and the other side supports 3 colours.  If you look in the printer driver maintenance tab for nozzle clean you get a choice of cleaning all 8 colours or Group 1 or Group 2.
Group 1 is Bk, R, G, PC and PM
Group 2  is C, M and Y.

The Pro100 is evenly split as follows:
Group 1 is PC, M, Y and PM
Group 2 is C, Bk, LGY and GY

For the Pro9000 the Service Manual specifies that if the120 hour timer expires; 1.1g + 0.8g of ink is purged.  That’s 0.238g per colour.

Before the scheduled purge, of my Pro 100, I weighed the LGY getting a result of 21.45g
After the 120 hour purge the LGY weighed 21.21g.  Hence 0.24g is right in the same ball park as the Pro9000, considering the accuracy of my scales.

While I was at it I did a few other tests:
- After first measuring the LGY, I waited a few minutes and measured it again, getting the same result.  This confirms that changing the cartridge in less than 60s avoids a purge.
After the 120 hour timed purge I waited a few minutes and turned the printer off,  then turned it back on a few minutes later, waited and measured the LGY cartridge again.  This time it weighed 21.20g.  The slight difference is probably just the accuracy of the scales again.
Bruce

On June 13th I sent a form feed to the printer at 19:30, which is about when I expected the 120 hour clean cycle to initiate.  Since I did not know the exact time of the previous clean, I was taking a guess.
I was a bit early and the form feed proceeded as normal without any preceding clean activity.  I sent another form feed 15 minutes later and it did result in the clean activity, followed by the form feed.

I recorded both the above actions on camera  and therefore was able to measure the exact time taken for all the activity.  I can advise that the clean action was 83s.  In addition I can advise that the period of inactivity after the form feed was 80s followed by a sequence of noises lasting 39s.

I recently sent a support request to Canon asking about the printer activity at turn on and following a print job.  The first response I received only referenced the turning on phase and was inaccurate, so I pointed that out in my reply and again asked about the activity after a print job.  The second reply was very vague and again did not answer the questions.  I decided it was a waste of time.  However I then received further responses asking if I was satisfied with the answers I decided to have another go.  This time I numbered the 2 questions and asked if they could answer the numbered questions.  The reply I got was just related to the first question ie. the power on activity.  In my forth attempt I just asked about the activity following a print job and finally got an answer.  So firstly here is the 3rd reply:

“Regarding your query, when you try turning on the printer the printer head tends to use a small amount of ink to make the machine ready in printing jobs. It uses small amount of ink just to lubricate the printer head and to avoid ink clogging.

The printer has the function to automatically clean the ink jet nozzles to prevent clogging. In the cleaning procedure, used ink for nozzle cleaning is limited to a small amount.

Ink may be used for purposes other than printing. Ink is not only used for printing, but also for cleaning the print head to maintain the optimal printing quality.”

Here is the 4th reply:

 “The noise you hear from the printer right after printing is a mechanical noise as the ink carriage is initializing to settle to its resting position.”

So if Canon support is to be believed, a small amount of ink is used at power on (via front panel switch) and no ink is used in the activity that follows a print job.

I thought it worth checking the Service Manual for the Pro9500, to see how it differs from the Pro9000, since it seems to have been used as a guide by many users.  The Pro9500 uses Pigment ink vs the Dye ink used in the Pro9000 and Pro100.  For the 9500 there are actually 4 timers specified but for 2 adjacent periods the amount of ink purged is the same so essentially only the following periods need be considered:
- Period 1 : less than 60 hours since last clean;  no purge occurs.
- Period 2 and 3: between 60 and 240 hours; 1.4g (A-ch), 1.8g (B-ch)
- Period 4: between 240 and 480 hours; 2.5g (A-ch), 2.8g (B-ch)
- Period 5: 480 hours or more since last clean;  4.2g (A-ch), 4.7g (B-ch)
I cannot see any note for the Pro9500 saying that no ink is used if ink tanks are changed in less than 60s, like the Pro9000.

Comparing the above figures to the Pro9000, which I did not mention previously:
- Period 1: less that 120 hours; no purge
- Period 2: between 120 and 480 hours; 1.1g (A-ch), 0.8g (B-ch)
- Period 3: 480 hours or more; 2.1g (A-Ch), 1.7g (B-ch).

That is quite a difference, especially if you don’t print for more than 480 hours.  ie potentially 8.9g on the Pro9500 vs 3.8g on the Pro9000.
The amount of ink is in grams, which is difficult to convert to ml.  If it was water at 4 degrees Celsius I believe it is a one for one conversion.  So I guess we can use the one for one conversion as a rough guide.

I don’t really intend doing anymore testing as a I think I have enough understanding now to reasonably limit the ink waste.  So here is my summing up:

i.   My first point is the most important.  You cannot stop the automatic purge of ink used to clean the printhead by sending a printjob or purge sheet to the printer, at least for the 4 printers mentioned in this thread, specifically the Canon Pixma Pro 9000, 9500, 100, and 100S.  If you send a print job every single day, the auto purge will still happen when the timer expires with the very next printjob.  The reason for the confusion is the wording in the Service Manual which says for example: “If 120 to 480 hours have elapsed since the previous cleaning till the start of the next printing.”  Confusing words but testing has clarified it’s meaning.  Printing does not restart the timer, cleaning does.

ii.  The automatic purge is triggered by a printjob, which can in fact be a purge sheet sent by say Qimage.  In this latter case an automatic purge will precede the purge sheet resulting in additional ink used, although I understand the ink used for purge sheets is minor.  A form feed will initiate the clean without using ink to print the purge sheet.  But normally just wait until the next print job.

iii.  The timing of the automatic purge is printer dependant.  However, for the above dye based printers it seems to be the same.  ie.  From 120 hours to 480 hours there is a small purge or double that if 480 hours is reached since last clean.

iv.  Many people seem to use 60 hours as the period after which an automatic purge will be triggered.  That seems to be based on the Pro9500 (and possible others)  and does not apply to the above dye based printers.

v.  The Service manuals also mention an automatic clean when a dot count is reached.  However no details are provided as to the value of that count.

vi.  Canon Support say that a small amount of ink is also used when the printer is turned on via the front panel.  Even more ink is used if the printer is turned on and off at the mains.

vii. Canon Support say ink is not used to clean the printhead following a printjob.

viii. For the Canon Pro9000, if you change an ink tank in less than 60s you can avoid an ink purge. I suspect this could apply to the above 3 dye ink printers but is less likely for the Pro9500.  I mention this specifically for those who plan to continue using OEM inks and are worried about wasting ink when changing just one tank at a time.  In fact for those who choose to use non OEM inks and were going to replace a full set at the same time,  may not need to do that.  They probably still need a second set of tanks because 60s is not a lot of time to refill.  Using squezy fill bottles with squezy cap system may be quick enough.  Need an expert opinion on that as I have never used the system.

viii.  There are a handful of events which could cause the printer timers to reset, such as: replacing a printhead, a manual clean or a fault condition such as the paper jam as mentioned in the previous post.

I have already changed my workflow.  I no longer send purge sheets to the printer every 2 days.  I reserve the purge sheet schedule feature, in Qimage, for times when I am likely to be away for an extended period of time, and will probably set the time interval for 1 week.  I still leave the printer on all the time but close the in and out tray to minimise dust getting inside the machine.  I am still unsure about the value of leaving the printer on.  Also, I am suspicious of the noises made 80s after a print.  About 20s of the noises sound very much like cleaning.  A notable difference is that the power light flashes during the known clean.  However, that is probably because there is a print job in the queue.

Finally a word on costs of the auto cleaning.  For the Pro9000 (and I assume the same for the Pro100 and 100S), if the printer is used regularly 1.9ml of ink is used every 5 days just for the auto clean.  To simplify the maths lets assume a 15ml cartridge costs $15, that means the purge cost $1.90.  Over 1 year there would be 73 purges costing $138.70 a year.  On the Red River website they have calculated costs of ink for different printers.  Here is the link for the Pro-100 http://www.redrivercatalog.com/cost-of-inkjet-printing-canon-pro-100.html.   Red River admit they have not included an allowance for cleaning.  Hence the above cleaning cost needs to be distributed over the actual printing costs.  The dot count cleaning would add even more.

That’s about it for now.  If anyone is interested in the 2 videos I used to measure the time to clean, let me know and I will upload them.
Bruce

Hi dannac and Terry,
Yes, I am very familiar with spreadsheets.  Perhaps we need a thread titled "Costs of Printing"?

Fred A alerted me to the logging data in Qimage, as reference by Terry.  In fact you can view my estimated costs in the Qimage Ultimate forum on about 1st or 2nd June.
I think my costs were blown out by the fact it is a new printer and there is a lot of ink used to prime the printhead.
Anyway in that post I included a link to a RedRiver website that estimates ink usage for different printers.
Which brings me Terry to your cost calculations.  I was staggered at how low your ink costs are.  As an example, the RedRiver site suggests an A3+ ink cost would be US$2.70, which equates to GBP 2.02.
Your costs of just GBP 0.27 is about 7.5% that of RedRiver.  Any thoughts on why there is such a big difference?

Tomorrow I will post an update on the purge/cleaning issue.
Bruce

Unfortunately my tests of changes to cleaning cycle due to powering off and on have been disrupted.
Today I had a paper jam.  To be precise it was a Canvas jam. Reported as Support Code 5100. Once I had cleared the jam,which involved a power down, I sent a nozzle check to the printer.
Thankfully the printer seems to have survived, but there was some major cleaning activity when I turned on and when I sent the nozzle check.
I am guessing my 120 hour clean cycle has now been reset as of about 19:30 today 8th June.  I will advise if it has not.

The paper jam was my fault.  The canvas is quite old and has not been stored flat.
Bruce

Just a quick update on this.  As expected my Pro-100S did its 120 hour clean last night.
I had sent several print jobs to the printer during the day without triggering a clean.
A few minutes after the 120 hour period had expired I sent a form feed (blank page from a word processor) to the printer which triggered the clean.
Based on the Pro9000 Service Manual I expected the clean to last about 85s.  I used the stopwatch on my mobile phone to time how long it would take, but managed to stuff that up.  The Pro-100 has a "Feed Slot Cover", which the Pro9000 does not and I regularly forget to close this cover.   If you forget to close the cover to orange light on the front panel flashes and a warning message appears on the computer monitor.   It is necessary to close the cover and either press the button associated with the orange light or click on a screen option to get the print job to proceed.
When I sent the form feed to the printer I had forgotten to close the Feed Slot Cover, the printer initiated the clean cycle and around 94s I was wondering why the page had not started to feed, when I noticed the orange light flashing. So I think we can assume it is somewhere between 85s and 94s if both channels are due for cleaning.

Soon after the page feed had finished I turned the printer off (about 23:02 on 5th June) using the power button on the front panel.  Today at about 09:00 on 6th June I tuned the power back on.  There was no clean function performed.  The printer took about 30s to power up, but I am positive there was no clean.  Also, about 1 minute later it made some more noises for about 30s.  Just to be sure I sent another form feed to the printer, while remembering to close the Feed Slot Cover and again there was no clean.

I wasn't originally going to do this but felt confident to turn off again via front panel and then turn of at the mains and then on again at the mains before turning on again at the front panel, waiting several minutes between each action.  This time the printer took just over a minute to power up.  Also, about 1 minutes later it made some more noises for about 30s.

I think the noises made about a minute after power up each time are more related to transferring waste ink.  In fact a similar thing happens whenever I send a print job to the printer.

I will now test at about 23:00 on 10th June to see if the powering down has changed the start time for the 120 hour clean
Bruce

 

I need to correct something I said in my original post.  ie. "since I have been using the Qimage purge sheets recently I expect both channels to flush at the same time"

Having thought about this I realise the Qimage purge cannot synch the 2 channels.  In fact the only 2 things I can think of that would cause the 2 channels to get out of sych are;
i. A manual clean of one channel, or
ii. Ink tanks related to just one channel are removed for more than 60s.
Conditions that would synch them again would be a manual clean of both channels, Print head removal and replacement or power off and on at the mains.

On the subject of powering off and on, I see nothing in the Pro9000 Service Manual about cleaning cycles if the switch on the front panel is used.  However, there is a significant clean:.....

"If the print head has not been capped before power-on".  In otherwords turn printer off on front panel before power down at the mains.
I may test the case when powering off using front panel, but have no intention of testing after powering of at the mains.  Ink is too expensive and I almost never turn off at the mains anyway.

By the way, using Qimage job log I can see the last print I sent to my Pro-100 which triggered a clean was at 22:55 on 31st May.  Hence I expect the next clean to happen when I send the first print job after 22:55 on 5th June.  Also, I can see there was a purge sheet from QI at 09:34 on 31st May which did not initiate a clean.  My point here is that the purge sheet did not stop the auto clean some hours later.
Bruce

Hi Mike,

Today I started a thread in the Printer forum as follows: http://ddisoftware.com/tech/printers/canon-pixma-pro-100s-cleaning-cycles/
In summary the article suggests that for some Canon printers, at least, printing a purge sheet is not important if the printer is in regular use.
eg.  A Canon Pixma Pro9000 and a Pro-100 will automatically initiate a clean cycle when it gets a print job, if a clean cycle has not been performed in a define period.

In the above case, a purge sheet is most useful when normal print jobs are not sent within the defined periods.
Hence my suggested improvement to QI is to introduce a tick box option such that when QI detects a successful print job to the specific printer, the duration counter be reset.

eg.  If I tick the new box for a Pro-100 and set the timer to say 6 days, if a normal successful print job is detected, the 6 day period would restart.

Regards
Bruce     

I have started this thread because I believe there is a general misunderstanding about the automatically generated cleaning cycles of the Canon Pixma Pro-100S and probably other Canon Pro models.
One of the common misunderstandings is that by using the printer, even just to print a nozzle check you can avoid an automatic cleaning cycle.  For the following 3 reasons I believe the cleaning cycles will happen regardless of whether a print has occurred:

1. I have observed it several times on my Pro-100S.
2. The Pro9000 Service Manual states that to be the case, so it is more than likely the case for the Pro-100 and 100S.
3. At least one other user has observed it to be the case for the Pro-100S.  (see https://www.printerknowledge.com/threads/canon-pro-100-user-some-new-findings-about-cleaning-cycles.12176/)

The Pro9000 Service Manual talks about 2 timers, ie.  120 Hours and 480 Hours.  Essentially:
a.  If you send a print job to the printer and less than 120 hours has elapsed since the last cleaning cycle, no cleaning takes place before the print.
b.  If between 120 hours and 480 hours has elapsed since the last clean, a small amount of ink is flushed through the head prior to the print emerging.  The quantity mentioned appears to be in grams so I will just reference the time mentioned for the cycle, which is either 85s if both channels are flushed, or 75s if only one channel is flushed.
c.  If greater than 480 hours has elapsed since the last clean then about twice as much ink is flushed prior to the first print.  The cycles being 115s for both or 100s for one channel.

On the Pro-100S I have observed the 120 hour cycle several times.  I would never have let it reach the 480 hours.  I have never timed the cycle period, but since I have been using the Qimage purge sheets recently I expect both channels to flush at the same time.

The above mentioned manual also mentions "dot count cleaning", which means the printer will also do a clean when a certain number of dots are printed since the last clean.  The count number is not specified as far as I can see.

I will be making some suggested changes to the Purge sheet option in Qimage based on this information.
Another useful piece of information in the above mentioned manual is the following statement:

"If an ink tank is removed for 60 seconds or longer, cleaning is performed.
(Cleaning is performed according to the period of time an ink tank is removed from the print head, regardless of whether the ink tank is
actually replaced or not. If the same ink tank is removed and installed back multiple number of times, cleaning is performed based on the
accumulated period of time the ink tank is removed.)"

There is no mention of when the timer is reset.  One would expect printing would rest this timer.
The obvious implication is that a clean cycle can be avoided if a tank is changed in under 60s.
Bruce

I have now tried this ink/paper reporting feature in QIU and believe it is a useful feature.  I recently saw a report on the Red River site (http://www.redrivercatalog.com/cost-of-inkjet-printing.html) which calculated ink cost based on surface area printed, so combining these 2 bits of information will help to calculate running costs.

Back to my original question I have now found a Service Manual for the Pro9000 which describes the cleaning algorithms used and I believe the Pro-100S to be very similar.
There is some useful information in the manual, most of which is probably best suited to the Printer forum, so I will start a thread there.

On the topic of QIU though I think I will make a suggested improvement to the purge sheet feature, based on the information in the manual.
Here is a quick teaser: If you change an ink tank in less than 60s, on the Pro9000, you can avoid a clean cycle.  Probably applies to several Canon printers.  They talk about an accumulation of time if you remove and replace the cartridge, but no clarification about the timer being reset, when printing for example.
Bruce

I did not know the ink levels were measured by Qimage.  That's fantastic.  I will give it a try.
Bruce

Hi Fred,
I have to admit I am very happy with the print results.  I previously had a Pro9000 and was astonished at how quickly it used up ink.  I knew it was doing numerous clean cycles and it frustrated me that it was using my liquid gold to perform these cleans.  I eventually made the huge mistake of installing a CIS which damaged the printhead which I replaced and then made another mistake of using non Canon cartridges.  I got several years out of that printer before it damaged yet another printhead.  It was only when I saw one of Jose's Youtube videos that I realised that the Canon carts really are more sophisticated than the 3rd party ones.

I thought with all my newly gained information I could introduce a workflow that would allow me to continue using OEM carts.
I just did a tally of all the prints I have done since buying the printer and checked the ink levels.  I am now undecided whether I will be using 3rd party inks in reset canon carts.
The stats are as follows:
- ink levels range between 60% and 70% full across all 8 carts.
- I have printed 16 x A4 paper profile sheets.  They tend to have a lot of white space, so lets say equivalent to 12 sheets
- I have printed 14 x A4 photographs.  Some had quite wide borders, but since I also did a number of small passport size tests and wallet size tests and one 6in x 4in print, I think 14 is a fair total.
- I have printed 4 x A4 purge sheets, (actually 8 x 0.5 sheets). However, these apparently only use a very small amount of ink.  Lets say 1 sheet.
- Printer initialisation used about 3 sheets, but again very low levels of ink.

So in summary, about 35% of my ink was used to print just 27 x A4 photographs.   Hence a full set of inks is only going to print about 77 x A4s at a cost of about Aus$2.12 each. About  US$1.60.
I could probably handle that, but if I slow down at all the cleaning cycles could become more of an annoyance.
It would just be reassuring to know what the printer is doing.  Is there really any point in doing the purge sheets if the printer is going to run clean cycles anyway?
Bruce

I have been using the Purge Sheet option of QI Ultimate for a little over a week on my 3 week old Canon Pro-100S.
I originally set the schedule for 2 days using a half page pattern.
I was surprised when I sent a normal print job to the printer and a clean cycle was initiated before the print was processed.  I estimate this clean cycle was about 42 hours since the last purge sheet.
I changed the schedule to 24 hours and one again a clean cycle was initiated before a print was processed.  In this case I estimate there was about a 5 day period between the 2 clean cycles and that it was only about 6 hours since the last purge sheet.
Interestingly, 5 days is 120 hours, which is a figure mentioned in forums for some Canon printers if they are not used to print regularly.
I am forming an opinion that the Pro-100S has an algorithm to run clean cycles even if the printer is used regularly.
I have been sending prints to the printer on a regular basis in addition to the purge sheets.
Any thoughts?