I just bought an Epson 7900. On the second day of priniting the head hits a canvas just in the first corner very hard and stucked in it. After a switch off of the printer and the remove of the jamed canvas, I started the printer again and made a new head alignment. Everything seems ok after this hard headstike, but now Iīm rahter unsure if this kind of headjams can destroy the printhead. Do you have any experience with headstrikes on the Epson 7900 or 9900?
I will be extremely interested to hear other people's responses. I have an Epson 9900. There are others on this forum with much more technical knowledge of printers than I have, so take what I say as a grain of salt as my experience - not necessarily representative of how your or other peoples' experience(s) will go.
I have always read that head strikes are awful, and can completely destroy them.
Yet, I've experienced what you have about ten times and have had no damage that I'm aware of. Every time this has happened, it scares the heck out of me, until I reboot the printer and complete a successful nozzle check. it's either been with Breathing Color Crystalline canvas on a roll, or scrap sheets of paper or canvas that came off a roll. (If I have to use a much larger roll due to what I have in stock, and there's useful scrap, I put it aside. When I'm not in a rush, I try to use this scrap later.)
I believe the Epson 9900 has a feature that when it detects a jam, it locks the printhead's position until the power is cycled - to ensure moving it doesn't cause damage. So, I don't think your heads actually stuck to the canvas -- I think it triggered this full stop.
The heads themselves (I believe) are at the top of the print carriage, since the unit only prints on the section of media approximately on the first inch that comes through the first set of rollers. The print carriage extends a lot further down (again, I believe.) I've read that the actual printheads have metal around them about as durable as tin foil, and can easily be damaged. When mine has jammed, it seems to jam at the bottom part of the print carriage, so I'm not sure I've ever had a paper jam be a true head strike.
I have had maybe two or three times where a tiny line of ink was on the media, indicating a light true head strike, but there was no paper jam. Had to throw out these few prints, but no damage that I'm aware of.
That all being said, I'm not sure if I've been extremely lucky, if a paper jam / head strike would be awful but are rare due to the bottom of the carriage often hitting the jam first, or if the worry is real but rare with a jam. I'd love to know, especially as I love Crystalline canvas, but it likes to jam unless you feed a lot through first as waste.
You should look at your canvas manufacturer's recommended platen gap setting for the 7700/9900. In the print driver, you can specify the thickness of the media in terms of standard/wide/wider/widest or something like that, with correspondingly increases the distance between the printer heads and the platen. Even if the manufacturer doesn't recommend higher, you can always move this up a notch or two which can help prevent this issue. If you run it too high, you can have blurriness -- whether this would be noticable or not for you, I don't know. Less likely on canvas than smooth or high quality photo paper.
The vacuum level you can select as you're loading media (I believe) only affects the vacuum being used while loading. I really wish there was a setting for during the print. I've been meaning to look around in service mode to see if there was something for this.....