Hacking the HP45

[evomotors]

@dragonator - yes, if you can send PCB's it would be great. Let me know how I can send you the money for shipping. I'm in USA.

[dragonator]

@evomotors - Paypal is easiest for me. I can email you or you can contact me through the contact form to exchange information.

A small riddle for the sunday afternoon. What is a millimeter wide and costs around 2 hours...
A disconnected print enable cable on the breadboard.

In all honesty, there was more wrong. I also made a mistake in the code, but the cable struck me as funny, if it wasn't for the fact that it cost me time. I got the HP45 to work again though, so here is where I am right now.

I have connected a teensy 3.2 to the printhead controller with the single 26 wire flatcable. There is no longer any additional electronics needed. All I do is wire the teensy 3.2 straight to the printhead controller. The code I run right now simply triggers all nozzles, but I am writing the code in such a way that it is usable in future upgrades. Push the button, 300000 droplets of ink come out of the head. The teensy is 3.3V, so I was still a bit worried that the controller would not work, but it works fine.

This code is primarily being developed for the teensy controllers. It can be modified for arduino relatively easy, but it is not drop in compatible. I use a teensy because I plan to use a teensy 3.6 for the Oasis printer.

This will most likely be the last ink update for today. I will try to post all data surrounding the controller as soon as possible.



(PS. I also got a new camera. I quite like it. You can even see the spray of ink and hear the squeal of the printhead as it deposits ink)

[jnesselr]

It looks pretty good! Can you upload the teensy code so I can take a look at it?

If each burst in the video is 300,000 drops, then that's an interesting speed to be firing at. That's a little over 42 mm if my math is correct. How closely does that align with the maximum printing speed if you don't angle the print heads? I guess it's more firing frequency here, which if I recall was around 12kHz when they aren't used at an angle and 20kHz when they are.

Either way, it looks very consistent!

[evomotors]

@dragonator - PM sent.

[dragonator]

Attached are the schematic of how I connected it and the firmware as it is right now. The code is only for reference. In the coming few days I will make all the functions working and add layers to the code. The end goal is that I can send an array to it and it will print it. After that I will start on the actual 3D printer so I can do my tests better.

Edit: note that the delay in the "printheadFire()" command should be 2, not 3.

HP45 teensy 3.2 connection schematic.png (228.34 KiB) Viewed 17207 times

[dragonator]

Might as well finish it

Attached is the carrier for the HP45 V1.01 controller as I have it right now. It is identical to this carrier except for the main body. The mechanism is the same and the parts requirements are the same.

http://ytec3d.com/hp45-breakout/

Hope it helps.

[evomotors]

@dragonator -check your PayPal. It's for 2 boards and shipping.

[evomotors]

@dragonator -Is it possible to daisy chain multiple HP45 using this controller? I'm planning to try CMYK...

[dragonator]

Daisy chaining itself will not be really possible. It is mostly parallel signals that go to the head. You can save a lot of wires by combining the primitive lines of all heads (and possibly the address lines). The primtives only trigger when the latch (primitive clock) is triggered. You can set up the primtives for one head, start the nozzles and during the 2us pulse or during some other delay you can setup and pulse another head. Worst case you will have to go a bit slower to get the data flow.

Also for the future, the HP23 might be an option. It is CMY, though with less nozzles.

[evomotors]

Or maybe I can use 4 individual controllers, one per color. And have one main controller to communicate with others through SPI.