Grommets on Canon printheads

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Tin Ho:
Re: the fiber thing... That would make sense in a limited way but would more likely be a cause of ink freeflowing out, rather than air leaking in and that would seem to be born out by the posts on the subject of sponge shift, etc... in previous threads.

With a CIS if there's air leaking in you have a problem in the sealed loop and whilst I considered the printhead nozzles I realised they are so small that it would require a great deal of suction/vaccum to result in air being drawn in that way. Add to that, if that was happening the nozzle pattern would be interrupted by air bubbles blocking some nozzles, so I've come back to the the cartridge nozzles and the grommet on the printhead as the vector.

As if to prove the point further, wrapping the thin silicon tape, I found, around the nozzle and then piercing it, to allow ink to flow, has done the trick... so really this is more about finding a simpler more elegant solution as the silicon tape will undoubtedly stretch and tear over time.


Herky: MIS are right about the spongeless design on Canons.. if you think about it, the nozzle is big enough that ink will easily be replaced by air through the same nozzle that air is supposed to exit from so a spongeless design has to take that into account and so far none of them have.


Grandad35: Thanks for that... I did think that a light sanding grain might be the best approach and combined that with the silicon tape and so far it seems to have done the trick.

As to the o-ring I'll see about trying that, it's just finding one that is thin enough and wide enough, especially for the BCI-3 and PGI-5 carts such that you get a tight fit.. Experimentation is key I guess..

 

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A washer cut from a soft rubber sheet should also work.

I have a Sinopis (chinese) CISinstalled on my MP730 and had the first unit installed by their technician. They obviously have come across this problem. He cut a small flat washer from a disposable glove and put it under the rubber seal to elevate it. However he only put it under the black and not the CYM.

 

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A washer cut from a soft rubber sheet should also work.

I have a Sinopis (chinese) CISinstalled on my MP730 and had the first unit installed by their technician. They obviously have come across this problem. He cut a small flat washer from a disposable glove and put it under the rubber seal to elevate it. However he only put it under the black and not the CYM.

Just out of interest, how did he cut the washer out? Any particular tools make the job easier?

I ask because I'm having a pig of a time working out how to do the same sort of thing myself..

 

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WebSnail - He had a number of washers in an envelope. They were obviously crudely constructed with a pair of scissors or a sharp scalpel blade. I don't think accuracy of the inner hole is important as long as the rubber grommet is elevated. But if you could get hold of a leather punch of suitable diameter a nice circular hole could be made.

 

[Grandad35]

Here are a few hits from googling "hollow punch" that should do the trick:
http://www.shop.com/op/~HOLLOW_PUNCH_SETS-prod-24831406-33106006?sourceid=298
http://www.ubid.com/American_Tool_Exchange_Hollow_Punch_12_Pcs_Set/a601649523-rsearchall.html
http://cgi.ebay.com/12-piece-hollow...0QQihZ015QQcategoryZ50380QQrdZ1QQcmdZViewItem

You will have to make sure that the punch set includes both a punch for the inner hole and the desired OD of the washer.

 

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Thanks for all the tips folks... I just did an eBay lookup using "leather hole punch" and found what I was after just down the road so I'm sorted now

I suspect that using the silicon tape as the material to create two grommets from should do the trick, it's relatively thin and will allow me to put one under the seal and one on top (between the seal and the cart)..

I'll let you know how I get on with my "trouble" cartridges once the punches arrive and I've had a chance to play.

Thanks again all..

 

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Figured it was time to feedback about this as I was able to buy some steel punches from eBay and just recently took them to the silicon tape I'd already sourced and managed to make some quite reasonable grommits for my Canon.

My approach was to make a grommit for each of the smaller CLI-8 cartridges and pop them over the existing rubber grommet. Simple!

The PGI-5 was a trickier animal as my punch set didn't include a hole that would fit tightly enough so I opted instead to use a small punch to create a small hole in a length of silicon tape, wrap it over the cartridge port, being careful to not to stretch it too far and then applying another length of punched tape over that with a slightly bigger hole.

Net result has been a much better flow of ink and a good seal to stop air getting in so my MP500 has now been successfully completed and works rather well (which is a bonus given the time that went into it).


It's a tricky process to complete if the silicon is as thin and stretchy as mine is but it is possible with a bit of patience and my thanks to all who suggested the solution..