Hacking the Xaar 128 printhead

Powder and inkjet printing
maxt
Posts: 30
Joined: Fri Apr 26, 2019 10:38 am

Re: Hacking the Xaar 128 printhead

Post by maxt » Sat May 25, 2019 4:52 pm

Hi guys, how do you raise the 3.3V levels of the teensy signals to the 5V that the XAAR expects ?
thanks in advance
Massimo

davidk
Posts: 71
Joined: Sun Mar 12, 2017 6:48 pm

Re: Hacking the Xaar 128 printhead

Post by davidk » Sat May 25, 2019 5:09 pm

I use a 74HCT574 powered at 5v. Its inputs can be driven at 3V3 and because it is powered at 5V it will output 5V. It's not the most correct way but for me works very well.

Braden
Posts: 6
Joined: Sun Aug 12, 2018 5:42 pm

Re: Hacking the Xaar 128 printhead

Post by Braden » Sun May 26, 2019 6:49 pm

Thanks for the help davidk. So your main ink reservoir is just open to atmospheric pressure and the ink is gravity fed to the ink damper? Did you have any trouble controlling the flow of ink so that your prints wouldn't be saturated? And maxt, I have just been using an Arduino Mega which can output 5V.

davidk
Posts: 71
Joined: Sun Mar 12, 2017 6:48 pm

Re: Hacking the Xaar 128 printhead

Post by davidk » Mon May 27, 2019 4:57 am

First damper had some leak but as long as tbe head was softly wiped printed ok.

maxt
Posts: 30
Joined: Fri Apr 26, 2019 10:38 am

Re: Hacking the Xaar 128 printhead

Post by maxt » Sat Jun 01, 2019 1:49 pm

Braden wrote:
Sun May 26, 2019 6:49 pm
And maxt, I have just been using an Arduino Mega which can output 5V.
I Branden, thanks, I know about arduino, however if I do this it has be a full color printer. I.e. 5 heads. I rule out arduino cause I doubt it would be able to drive and synch all of these heads. Some recent teensy (3.3V) should be ok, if they have enough pins.

Wonko
Posts: 93
Joined: Sat Aug 15, 2015 8:13 pm

Re: Hacking the Xaar 128 printhead

Post by Wonko » Tue Jun 04, 2019 1:36 pm

Teensy have enough pins. If you need more, Arduino Due are an option (ARM CPU). Xaar heads use a serial protocol and can be daisy-chained. If you can be fast enough, you can control as many heads as you wish with the same control pins.

BlueTurtle
Posts: 8
Joined: Mon Feb 13, 2017 5:29 am

Re: Hacking the Xaar 128 printhead

Post by BlueTurtle » Tue Aug 06, 2019 5:14 am

Hello everyone...

I'm having some trouble with my Xaar 128.. The printer was working fine with Kyle's code (https://github.com/gkyle/xaar128/blob/master/xaar128.h) with a simple addition of stepper motor header file and class but for some reason it stopped working...

I'm using a 36V power supply with 220uF cap for VPPH and 10uF cap for VPPL with 30N06L N-Mos for controlling the power up and power down sequences. I have tried to capture what's going on with my logic analyzer and out of my Mega I'm getting the CLK (1MHz) signal just fine, SCK just fine ( I guess?) but no MOSI or MISO signals... Also even though I don't know definitely, I'm thinking that I might have somehow burnt the Xaar ICs. Can someone please check what's the Ω between GND and GNDL. I'm getting 0.6Ω, which I think isn't right.

Also between it not working and working I just plugged it out because I was leaving the house. And I would be really happy for any other method other than low side n-fet for powering the printhead. Should I try something on high side since the manual says the power sources should be isolated and their grounds should not be connected anywhere else as they are connected inside the printhead... (I obviously connect the Source of the fets to Arduino ground, 12V ground (for stepper and step down regulator for Arduino)
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davidk
Posts: 71
Joined: Sun Mar 12, 2017 6:48 pm

Re: Hacking the Xaar 128 printhead

Post by davidk » Tue Aug 06, 2019 6:04 am

Hi,
It's normal to uave a short between GND's. I have a full working set I build and I have a single 24V supply. 24 goes to motor drivers, to a 7805 stabilizer and to a booster for head voltage. Don't use 36V, I use only 29...30V instead of 35. In fact, adjust the voltage according to the ink viscosity until you have a minimum of satellite drop spits.

So: common gnd is OK, 30V instead of 35 is OK.
DO NOT:
- Use water
- Pull the printhead out of socket while powered
Any of those WILL destroy the printhead.

BlueTurtle
Posts: 8
Joined: Mon Feb 13, 2017 5:29 am

Re: Hacking the Xaar 128 printhead

Post by BlueTurtle » Wed Aug 07, 2019 4:39 am

Thank you for your response... I guess I fried my Xaar head need to get a new one :roll: :roll: ... :lol: What kind of booster are you using? I'm really hesitant using a cheap boost converter off of amazon/ebay because of transient voltage peaks that one might encounter during powerup.

davidk
Posts: 71
Joined: Sun Mar 12, 2017 6:48 pm

Re: Hacking the Xaar 128 printhead

Post by davidk » Thu Aug 08, 2019 6:24 pm

I use a cheap 3A booster from ebay. It seems it's stable enough. It's not quite rocket science. For me the hardest part was to build the mechanical capping. It works good now, I use the same printhead since february and it have all nozzles firing ok.

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