Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

previous by date index next by date
previous in topic topic list next in topic

Subject: Re: [Homebrew_PCBs] Re: Homemade flatbed inkjet pcb printer

From: Volkan Sahin <v_sahin@...>
Date: 2008-04-07

Hi Dave,
I think we need to use fpga because of timing issues. If we assume that scanning 1 line (8" width paper/pcb) requires 1 sec and we're trying to print at 720dpi, this means that we have 1/(8∗720) sec or 174 microseconds for each dot. During this time you also need to download next position data to the head. The alternative solution can be not to print at 720dpi and do multiple pass to achieve 720dpi.
Another issue the timing needs to be precise otherwise it can cause inconsistency in dot positions.
The inkjet head that I'm using requires 212bits for each color (90 nozzles/color) and uses double edge clocking for the sampling. From that your clock frequency should be at least 700kHz.

Because of above reasons I have decided to use fpga.

Cheers,
Volkan


pork_u_pine2000 <wittend@...> wrote: --- In Homebrew_PCBs@yahoogroups.com, "v_sahin" <v_sahin@...> wrote:
> Hi All,
> I spent couple of months(~4 months) to design my own flat bed inkjet
...
> Note: I don't know whether the details of the design is an off topic
> or not for this group. I need feedback from Steve.

I am fascinated by what you are doing. I would dearly love to know
more about your work. It sounds as if you are getting excellent
results after putting in a ∗lot∗ of hard work, doing things in what
seems to me one of the best ways.

A design done in FPGA may not excite the maximum amount of interest
amongst all readers here, but I can see how doing the design this way
gives control over critical parameters you might not be able to
optimize otherwise.

I can only speak for myself, but this seems eminently on-topic to me.

-- Dave






---------------------------------
You rock. That's why Blockbuster's offering you one month of Blockbuster Total Access, No Cost.

[Non-text portions of this message have been removed]