Hacking the HP45

[dragonator]

@Mahjam, Voltage on the HP45 is a difficult subject. To as far as I know it has a variable voltage. It is designed to run on something between 8V an 13V. The printhead controller needs to figure out the ideal voltage based on how much the printhead heats up. I have not yet tried any of this myself, but it would mean that the 8.7V would be within the range.

I do not have a real answer sadly. I don't know if it will work. It should probably work, but I cannot guarantee that it won't have a shorter lifetime.

[Wonko]

Hey Restani, if you have a working schematic to drive the XAAR 128 can you please share it? I would be really happy! Thanks and have a nice day everyone.

There is a Xaar thread in this forum:

http://ytec3d.com/forum/viewtopic.php?f ... 1709#p1709

Xaar printheads have all the electronics built-in. You control them via a standard SPI microcontroller connection. It's all well documented and available in the thread above. Now, if you think to yourself, why would I hack the HP45 then? The Xaar 128 cost between $200 and $300. That's why.

[Restani]

Thanks Wonko!

I'm participating in the forum! Learning a lot!

[BlueTurtle]

Hey Restani, if you have a working schematic to drive the XAAR 128 can you please share it? I would be really happy! Thanks and have a nice day everyone.

There is a Xaar thread in this forum:

http://ytec3d.com/forum/viewtopic.php?f ... 1709#p1709

Xaar printheads have all the electronics built-in. You control them via a standard SPI microcontroller connection. It's all well documented and available in the thread above. Now, if you think to yourself, why would I hack the HP45 then? The Xaar 128 cost between $200 and $300. That's why.

Yeah I should have done my homework lol. Thanks for pointing in the right direction. The cost of Xaar 128 vs HP45 is imo justified since Piezo gives more ink options.

[david]

Hey Restani, if you have a working schematic to drive the XAAR 128 can you please share it? I would be really happy! Thanks and have a nice day everyone.

There is a Xaar thread in this forum:

http://ytec3d.com/forum/viewtopic.php?f ... 1709#p1709

Xaar printheads have all the electronics built-in. You control them via a standard SPI microcontroller connection. It's all well documented and available in the thread above. Now, if you think to yourself, why would I hack the HP45 then? The Xaar 128 cost between $200 and $300. That's why.

Also Xaar printhead does not support aqua based liquid, which is safer and cheaper for 3D printing.

[davidk]

Hi,

I made it work, now I can print graphics with HP45. Here is a sample printed on glass and another on paper. However, the output is a bit faint, althoug all nozzles are firing. I tried with 2.0us primitive time @12.0V, I'm afraid to go further. Should I fire the same pattern more than once for deep black?
How much can I increaze nozzle firing time without burning the head?

Another thing, I'm working at a starting sequence for spitting the dried ink in the nozzles. I don't know yet if I should fire more aggressive in the priming sequence but I'll do more tests.

As used only the first 128 odd nozzles (from a single row) for software simplicity.

Ah, another thing: I purchased an old used HP1220c printer ($25) to get the printhead socket and capping.
Please see my other posts about the schematic used, don't ask me again about this without reading, please.

[frankie]

nice

[dragonator]

Great work on getting it to work. It looks great.

From what I have read, the thing you need to get more energy in the nozzle is not firing time but voltage. The original controller never changes firing time (only for warmup, and that is 700ns). It beforehand tests the head to see which voltage is most efficient and uses that. Also, you can't really vary the ink output. You will get what is in the firing chamber, nothing more. Increasing time or voltage will not change anything.

A few thing you can do. You are printing with a 300 DPI section spaced at a 600DPI resolution (using only one side). The sides are offset by half a nozzle. You firing only half of the head means that you are printing half of what it is supposed to. This might be a cause for the faintness. You can also fire the head at more than 600DPI in the printing direction to get better coverage. This works better on paper, where the ink spreads a little. This is one way I got better coverage on Plan B as well.

The starting firing sequence is to my knowledge usually accompanied by a mechanical station that wipes the head. I don't know if there is a purely software way to clear the head. More aggressive seems like the wrong idea though. After the nozzle has fired, there is nothing that extra energy will do other than damage the printhead. There is no ink to heat anymore. Some printers also occasionally fire all nozzles to keep the ink from drying too much while the printer is in standby.

[mahjam]

@Mahjam, Voltage on the HP45 is a difficult subject. To as far as I know it has a variable voltage. It is designed to run on something between 8V an 13V. The printhead controller needs to figure out the ideal voltage based on how much the printhead heats up. I have not yet tried any of this myself, but it would mean that the 8.7V would be within the range.

I do not have a real answer sadly. I don't know if it will work. It should probably work, but I cannot guarantee that it won't have a shorter lifetime.

Hi Dear Dragonator, Thank you for your guidance. I tested it With v1 controller and the result was good .and ink is not removed from PVC. I think to test on the glass it is better to use this kind of cartridge.
one question, How can I control each nozzle? What skills do I need? I want to print a circle shape and my programming skill is weak.

[mahjam]

Hi Dear Dragonator, Thank you for your guidance.
why don't work export section in your example program of proseccing?
I can't get text output by program.
thanks alot.