MG7120 - roller mark problem - is this normal or clearly faulty?

[speedsiren]

Hi guys, just joined the forum, thanks for your advice in advance

I've recently purchased Canon MG7170 printer (Asian equivalent of MG7120 sold in the States) and I fear that there may something wrong with it. Despite good printout quality, I was quite concerned about the roller mark? trail? that it left on the underside of the paper, please see attached photo, is this considered normal? The scratches are quite deep in the darker area. Perhaps the paper I printed on is too thin?

The paper is plain A4, 90gsm - Media Type setting is 'Plain'. These long scratches are visible in all three print quality settings; high, standard and draft.

I've tried bottom plate/roller cleaning, 'prevent paper abrasion' all to no avail. I was thinking about shipping this to Canon service center but wanted to check here first. Is this something that can be fixed or reduced? I don't remember my other (cheaper) Canon printers ever did this...

Any Canon users experience this?

Thanks again for your help.

 

[palombian]

The photo is not very clear.
Are then lines caused by ink on the small rollers on the bottom plate ?
I had this on my MX7600.
You can remove it by long bottom plate cleaning jobs, but I also used a small roll of kitchen paper pushed against the rolls while they turn during cleaning.
More important is to find the reason. I never had a prove, but in my case it was a clogged purge unit causing the printhead leaking ink while travelling.
Also a lot of borderless printing can cause of ink on the platen sponge leaking down on the rollers.

 

[Łukasz]

This phenomenon is because of "spur unit" design (official name of this assembly from service manual). Paper is too much soaked with ink and is easily deformed by spurs.

(spurs are small hedgehog-like wheels, mounted on springs; there are many of them on the opposite site of metal plate with serial number)

Unfortunately, there is no way to manual adjust spur unit clearance. Theoretically it can be done easy with some kind of needles placed instead of CD-tray "bayonets".

Ł.

 

[PeterBJ]

I had not noticed this behaviour from Canon printers before, but I printed a large image with lots of ink on a sheet of plain paper using plain paper setting on an iP4200. This showed the same spur marks and deformation of paper, but to a much lesser extent.

The paper used was a cheap copy paper, intended primarily for laser printers and photo copiers but also acceptable for inkjet printers. The large amount of ink wetted the paper and caused it to expand, the paper expanded and buckled from the ink. After the ink had dried the paper was almost flat and the spur marks barely visible.

Here is a shot of the spur wheels in a Canon iP4200, shot using a cheap USB borescope/inspection camera:

It is often overlooked, but paper quality might be more important for print quality than the printer and ink. Maybe a thicker high resolution paper specially made for inkjet printing will behave better? This paper is of course more expensive than plain copy paper, so maybe it should be used only for important documents.

 

[stratman]

100 Likes for the image, PeterBJ!

 

[Smile]

Here is a shot from brother MFC that I have.


@PeterBJ
What camera do you have, you seem to have better quality, I have 5.5mm camera, got it for 4$ after I found out it to be 0.3MP instead of 1.3MP

 

[PeterBJ]

I think the USB borescope/inpection camera is this, made in China. It looks exactly identical to my camera.

The round knob is for adjusting four bluish white SMD LEDs and the larger push button is for capturing an image. The bundled software doesn't work properly with Windows 8, but at least Irfan View will accept it as a scanner, allowing me to capture an image. Not very handy as I have to hold the camera using one hand and use my left hand for the mouse. I have just downloaded a Windows 8 driver, I hope that works better.

But the camera was cheap, IIRC I paid less than DKK 100 or USD 17 or Euro 14. I guess the price was half normal retail price, as the packaging was slightly damaged.

The site is a lot of nonsense with very little factual info, and written in bad English, but as maximum resolution for the camera is 640 x 480 it must be a 0.3 MP camera like yours.

I don't understand the 5.5 mm measure for your camera, is it the diameter? If so it is much more handy than my camera. I couldn't get a decent scan of the camera seen from the end, so I made a sketch:

The 1 mm dia is the lens aperture, the 6.3 mm dia is the black plastic lens holder and the 14 mm dia is the outer diameter of the camera. The camera and LEDS are covered with glass to make it (somewhat?) waterproof.

 

[Smile]

I got this camera
http://www.aliexpress.com/snapshot/6237862915.html

It is only 0.3MP not 1.3MP, so I demanded refund and got it for 4$ because I demanded 15$ back. Seller did not say anything so aliexpress automatically refunded me.

Yes the camera is 5.5mm diameter, very handy. Originally bought for inspecting air tank for oil free compressor, but later I decided to replace the tank to a bigger one 24L tank from stainless steel.

The camera works fine in good light, no so in the dark, very much noise. Also heat from leds add to the noise too. So in the light it works better with leds off.

My camera has 5 Meter USB wire. I had to add my own ferrite's to it.
The camera image quality demo shots on seller site are fake.