Hacking the HP45

Powder and inkjet printing
randoh
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Re: Hacking the HP45

Post by randoh » Mon Jun 11, 2018 9:33 pm

Hey

I've been reading trough this, and have the idea to try and control a HP45 cartridge myself, but with regular ink for a DTG type printer. I have a few questions, I've thought of while reading trough your experiments. Not my first AVR project, by far, but the most complicated and possibly stupid idea so far.


1.Would a ULN2003A suffice for driving the Address and Primitive pins? As I have understood, it should handle the current and voltage with flying colors. What about the timing? As I have read, the timings are extremely percise, to get the cartridge to fire and not burn out? Literally noone sells the TLC59213 anymore except 20x at a time for 40 bucks here in Estonia :/

2. If I understand correctly, is this the process of ejecting a droplet? Could you specify the timings please?
1) Set Address X HIGH (As I understand, this is the "nozzle's row select" ?)
2) Wait N uS
3) Set J+1 primitives HIGH (the nozzles on that row, if I understand correctly?)
4) Wait Y uS
5) Shut off primitive
6) Shut off address

and If the primitives and addresses are not currently used, 10k them to ground.

Sounds relatively straightforward, if printing speed and doing this a bazillion times a second is not a concern :D

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boooster
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Re: Hacking the HP45

Post by boooster » Tue Jun 12, 2018 11:20 am

Hi to all,

Svarichevsky Mikhail Aleksandrovich from Zeptobars das done a amazing weekend die shot from a HP45. Have a look: https://s.zeptobars.com/hp840c-bw-HD.jpg
HP45 die shot_small_800px.jpg
HP45 die shot_small_800px.jpg (205.92 KiB) Viewed 3481 times

randoh
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Joined: Mon Jun 11, 2018 9:24 pm

Re: Hacking the HP45

Post by randoh » Thu Jun 14, 2018 4:14 pm

Hi, do you have any connectors available and what's the price for them, with shipping to Estonia?

Apryl
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Joined: Fri Jun 15, 2018 4:59 pm

Re: Hacking the HP45

Post by Apryl » Fri Jun 15, 2018 5:07 pm

Can you send me documentation on the C8855M.

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dragonator
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Re: Hacking the HP45

Post by dragonator » Sun Jun 17, 2018 3:23 pm

My apologies for not responding much. I am a bit flooded with work at the moment.
randoh wrote:
Mon Jun 11, 2018 9:33 pm
1.Would a ULN2003A suffice for driving the Address and Primitive pins?
I always suck at reading datasheets, most notably current direction. It seems to me the ULN2003A are sinking darlington arrays. Timing wise they are OK, but the HP45 absolutely needs high side driving. This is the only reason why I am stuck with the TLC59213. It is the only high current, high speed, high side (latching) driver IC I could find.
randoh wrote:
Mon Jun 11, 2018 9:33 pm
2. If I understand correctly, is this the process of ejecting a droplet? Could you specify the timings please?
1) Set Address X HIGH (As I understand, this is the "nozzle's row select" ?)
2) Wait N uS
3) Set J+1 primitives HIGH (the nozzles on that row, if I understand correctly?)
4) Wait Y uS
5) Shut off primitive
6) Shut off address
That is correct. Delays are a bit vague to me as well, but I keep them there for lifetime. Address open, primitive open, fire delay, primitive close, address close. Addresses have a fairly high capacitance and a tendency to open when floating, so either have an ICwith high enough pulldown (like the 4017) or tie it to ground.
randoh wrote:
Thu Jun 14, 2018 4:14 pm
Hi, do you have any connectors available and what's the price for them, with shipping to Estonia?
I do have connectors available. I also have breakout boards available. I can mail you with the details if you are interested.
boooster wrote:
Tue Jun 12, 2018 11:20 am
Svarichevsky Mikhail Aleksandrovich from Zeptobars das done a amazing weekend die shot from a HP45. Have a look: https://s.zeptobars.com/hp840c-bw-HD.jpg
That is an absolutely gorgeous die shot. It even has the numbers for the nozzles, addresses and primitives etched in there.

randoh
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Joined: Mon Jun 11, 2018 9:24 pm

Re: Hacking the HP45

Post by randoh » Wed Jun 20, 2018 12:01 pm

In that case... would some fast transistors work for prototyping?
The 59213's are nowhere to be found in DIP, for <20$...

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dragonator
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Re: Hacking the HP45

Post by dragonator » Wed Jun 20, 2018 5:19 pm

If SMT components are available you can look into SMT to breadboard breakouts for the TLC59213. If that fails, you can use mosfets or transistors to drive the printhead. One thing to keep in mind though, you are driving high side, which generally requires PNP transistors or P-channel mosfets. A thing to keep in mind.

anilmaddala
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Re: Hacking the HP45

Post by anilmaddala » Fri Jul 13, 2018 6:29 am

Hi dragonator,

Awesome work! any idea when you might be selling the pcb's and rhe finished product.

Do you think we could use nylon powder to print 3D models using the HP45 print head? What kind of ink would you need to do printing with nylon powder?

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dragonator
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Re: Hacking the HP45

Post by dragonator » Mon Jul 16, 2018 6:02 am

I am stuck in software limbo for a while, while I finish all functions needed to make the printhead work. This took considerably longer because I needed to learn python from scratch. I am almost done, but I cannot work on it for a few weeks due to vacation and stuff. PCB's will happen at least after that, so my soonest indication for officially selling PCB's would be two months. Unofficially selling would be a month, mostly due to vacation.

I do not know of a binder that would work directly in nylon that would allow you to use the strength of nylon itself. I do know of a technique that prints IR absorbing ink into a powder, than moves over with a heat lamp to locally melt or sinter the powder where the IR ink is.

anilmaddala
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Re: Hacking the HP45

Post by anilmaddala » Mon Jul 16, 2018 6:35 am

I know a bit of python. Let me know if I can help. May be a git repositry?

Do you know what ink is used for nylon sintering?

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