Inkjet printer direct to PCB (printer hack/conversion)?

[Ioannis]

Don't worry about the time this will take. I'll be subcribed to this thread for ever (sort of speak...)

Now about the sensor, why that bothers you?

If it works, leave it. I suppose it contributes to the initial position of the paper/pcb, right?

Ioannis

[mackrackit]

If you have some sort of tray to place the PCBs on then the sensor could be used as a locator as it is designed to. Then when the etching is finished the PCBs could run again for the silks.
Maybe...

[HankMcSpank]

Now about the sensor, why that bothers you?

If it works, leave it. I suppose it contributes to the initial position of the paper/pcb, right?

Ioannis

At this early stage, I'm not even sure why it bothers me!

I know it's certainly appears to be a hassle for a lot of diy 'direct to pcb' printer conversions.....it's my understanding that it's only role is to find the leading edge of the paper - but the end goal here is near perfect repeatability & 'registration' - not sure how achievable that will be with a system that use friction rollers & an optical edge finder.

....but like I say, it'll become clearer in head the best strategy for me to pursue over the coming days.

[Ioannis]

I do not like the friction too. And this technology is not suposed to have good repeatability. Every time the rollers move the paper/pcb/whatever, they are losing a little of their diameter. So it is sure that this cannot be very accurate.

Another idea might be to use the steppers that move the rollers, to move a table having the pcb on it. Difficult as there are no datas about the motors and the gear involved.

Ioannis

[HankMcSpank]

I do not like the friction too. And this technology is not suposed to have good repeatability. Every time the rollers move the paper/pcb/whatever, they are losing a little of their diameter. So it is sure that this cannot be very accurate.

Another idea might be to use the steppers that move the rollers, to move a table having the pcb on it. Difficult as there are no datas about the motors and the gear involved.

Ioannis

Well fortunately this particular printer (Epson C66) appears to use a stepper for the paper feed motor, so in principle it should be just a matter of feeding those wires to either the original stepper but relocated to the front/middle of the printer driving a leadscrew (or use my own stepper - there's seems a little small!). Then just a matter of dividing the pulses to achieve the right feed rate.

I believe someone has done this (albeit with an HP printer) as I saw a youtube video relating to it.

The hour or so of dabbling to date....shows I'm in diffs already. Apparently the optical sensor has to be relocated very precisely to get the right timing - else the printer just gives a paper feed error. Hey ho!

[HankMcSpank]

Ok, making some progress.

I've decided on the easy option - don't dick with the head height & simply feed 0.8mm copper into the printer! (no outlandish hacking needed)...

This is 0.8mm double sided copper....



So the procedure is...

1. Buy a secondhand epson printer that uses durabrite ink (this is pigmented ink & means your 'possible contender' printer is capable of doing direct to copper printing)

2. Remove just about all the paper feed mechanisms *except* for the friction roller which pulls the copper through)

3. Relocate the optical sensor to a more appropriate place (this was an earlier test using paper to establish how to spoof the sensor)...



(that's the optical sensor to the right of picture with the blu-tack holding it in place)

4. Tape a little bit of card to the copper (to spoof the optical sensor that it has found the paper edge)

An then reference this video for the actual feed sequence...




About 2 hours work in total (less now that I've done one & therefore know the shortcuts!)

[Ioannis]

OK. Well done so far.

What about the printed PCB? Is the ink solid and dry on the copper?

Have you tried to etch it?

Ioannis

[mark_s]

Hank,

Great progress! You might inspire me to rip my Epson apart soon.
My big concern was the ink. Some of the guys were having trouble while others
seemed to be getting ok results. Need to research some more

I was thinking of taking a couple of ball bearing drawer slides and mounting a tray on top to hold the pcb. This would keep the alignment perfect and lower the friction.

Keep us updated

Regards
Mark

[HankMcSpank]

OK. Well done so far.

What about the printed PCB? Is the ink solid and dry on the copper?

Have you tried to etch it?

Ioannis

This (Epson) ink smudges (even after an hour) - but I knew this would be the case. Alas you have to bake the board to 'fix' the ink.

I've not baked nor tried to etch - this is just early experiments (clearly I need a better method to feed the copper in) - also it would appear a couple of the nozzles are blocked (I'm seeing the odd horizontal streak/line where no ink is on the pcopper)

Hank,

I was thinking of taking a couple of ball bearing drawer slides and mounting a tray on top to hold the pcb. This would keep the alignment perfect and lower the friction.

Mark

I'd say that's got to be a good idea - I'm thinking about a 'bed' behind the printer which the pcb rests on - but with adjustable cheeks, to align/guide the pcb where I want it (I can't be done with the faff as seen here - ...not knocking his achievment, as that video helped me a lot, but IMHO that's what the net is all about...being inspired by others aaccomplishments & chievments to hopefully take it to the next level).

So I'd say 'go for it'....it's surprisingly easy (if you're happy printing onto 0.8mm copper clad that is!)