One-sided Comms board

Zach - thanks for the one-sided comms board design. I've made a few hacks:

1. Expanded pads on most things to 0.08"; makes it easier to drill, and
we're not running tracks between pads except for the D connector, for
which I left the appropriate two smaller. Thanks for pointing out that
you can use the module editor from within the PCB design; that makes
this sort of thing so easy.

2. Moved the 100 uF cap nearer the regulator to keep it sweet.

3. Fixed the 78L05 connections.

4. Fattened the +12v tracks even further; they may need to take almost
10A in the finished machine.

Mods attached.

I haven't tested it yet as my old home laserprinter has just gone to
meet its maker (either Mr Hewlett or Mr Packard...)


Yours

Adrian

[staff.bath.ac.uk]
[reprap.org]

fantastic! i'll put this into subversion, and this week i'll actually
fabricate a couple. i'll be taking lots of pictures for the wiki
entry. it should be an easy update... the only thing that has
really changed is the layout of the circuit.

also, on the universal controller howto there are tests you can do to
make sure that the board works... is there anything other than
verifying that the LED turns on that one can do to test the board?

one more thing.... i noticed that kicad does a pretty nice
auto-silkscreen job. i'll be including that in the wiki entry since
its pretty helpful for construction, and if you're doing toner
transfer then you can physically put it on the board once you etch the
board!

~Zach

On 3/4/07, Adrian Bowyer wrote:
>
> Zach - thanks for the one-sided comms board design. I've made a few hacks:
>
> 1. Expanded pads on most things to 0.08"; makes it easier to drill, and
> we're not running tracks between pads except for the D connector, for
> which I left the appropriate two smaller. Thanks for pointing out that
> you can use the module editor from within the PCB design; that makes
> this sort of thing so easy.
>
> 2. Moved the 100 uF cap nearer the regulator to keep it sweet.
>
> 3. Fixed the 78L05 connections.
>
> 4. Fattened the +12v tracks even further; they may need to take almost
> 10A in the finished machine.
>
> Mods attached.
>
> I haven't tested it yet as my old home laserprinter has just gone to
> meet its maker (either Mr Hewlett or Mr Packard...)
>
>
> Yours
>
> Adrian
>
> [staff.bath.ac.uk]
> [reprap.org]
>
>
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i fixed one small bug... the reprap text was mirrored. on the design
it needs to be normal, the mirroring gets handled when you do the
plotting.

On 3/4/07, Zach Hoeken wrote:
> fantastic! i'll put this into subversion, and this week i'll actually
> fabricate a couple. i'll be taking lots of pictures for the wiki
> entry. it should be an easy update... the only thing that has
> really changed is the layout of the circuit.
>
> also, on the universal controller howto there are tests you can do to
> make sure that the board works... is there anything other than
> verifying that the LED turns on that one can do to test the board?
>
> one more thing.... i noticed that kicad does a pretty nice
> auto-silkscreen job. i'll be including that in the wiki entry since
> its pretty helpful for construction, and if you're doing toner
> transfer then you can physically put it on the board once you etch the
> board!
>
> ~Zach
>
> On 3/4/07, Adrian Bowyer wrote:
> >
> > Zach - thanks for the one-sided comms board design. I've made a few hacks:
> >
> > 1. Expanded pads on most things to 0.08"; makes it easier to drill, and
> > we're not running tracks between pads except for the D connector, for
> > which I left the appropriate two smaller. Thanks for pointing out that
> > you can use the module editor from within the PCB design; that makes
> > this sort of thing so easy.
> >
> > 2. Moved the 100 uF cap nearer the regulator to keep it sweet.
> >
> > 3. Fixed the 78L05 connections.
> >
> > 4. Fattened the +12v tracks even further; they may need to take almost
> > 10A in the finished machine.
> >
> > Mods attached.
> >
> > I haven't tested it yet as my old home laserprinter has just gone to
> > meet its maker (either Mr Hewlett or Mr Packard...)
> >
> >
> > Yours
> >
> > Adrian
> >
> > [staff.bath.ac.uk]
> > [reprap.org]
> >
> >
>
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Quoting Zach Hoeken :

> i fixed one small bug... the reprap text was mirrored. on the design
> it needs to be normal, the mirroring gets handled when you do the
> plotting.

No - it's better to leave it as it was and to plot it un-mirrored.
That way the laser toner is on the side of the OHP sheet that touches
the board and you get cleaner edges.

Yours

Adrian

[staff.bath.ac.uk]
[reprap.org]
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Hmm. I understand what you're saying. However, that would mean that
we need separate files for both toner transfer and the photo transfer.
(That is a bad thing.)

The way I'm suggesting is to have the board and text normal in Kicad,
but do the mirroring in the Plot section of kicad... when it gets
output to postscript. Then it should be on the right side when you go
to etch.

You should be able to take that, flip your transparency over (so the
toner is on the copper) then do your normal process. Am I missing
something?

~Zach

On 3/4/07, Adrian Bowyer wrote:
> Quoting Zach Hoeken :
>
> > i fixed one small bug... the reprap text was mirrored. on the design
> > it needs to be normal, the mirroring gets handled when you do the
> > plotting.
>
> No - it's better to leave it as it was and to plot it un-mirrored.
> That way the laser toner is on the side of the OHP sheet that touches
> the board and you get cleaner edges.
>
> Yours
>
> Adrian
>
> [staff.bath.ac.uk]
> [reprap.org]
>
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Quoting Zach Hoeken :

> sorry, i meant if there are any more tests for the powercomms board
> itself, see the last testing section on the wiki:
>
> [reprap.org]

No - though now you've asked I've just thought of an obvious one: short
the transmit and receive lines that would go to the ring, plug it into
a serial port, and check that a terminal program (like minicom or
hyperterminal) echoes to its screen.

Yours

Adrian

[staff.bath.ac.uk]
[reprap.org]
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Quoting Zach Hoeken :

> Hmm. I understand what you're saying. However, that would mean that
> we need separate files for both toner transfer and the photo transfer.
> (That is a bad thing.)
>
> The way I'm suggesting is to have the board and text normal in Kicad,
> but do the mirroring in the Plot section of kicad... when it gets
> output to postscript. Then it should be on the right side when you go
> to etch.
>
> You should be able to take that, flip your transparency over (so the
> toner is on the copper) then do your normal process. Am I missing
> something?

I think we have one too many flips. Imagine looking down on the board
from the component side (which is the view Kicad gives you when you're
editing). Now imagine your transparency with the pattern on under the
board, with its toner touching the copper. That's what Kicad shows
you, what you want to print, and what you want then to put on the
board. No mirror involved at any stage.

Or maybe I'm missing something :-)


Yours

Adrian

[staff.bath.ac.uk]
[reprap.org]
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well, i think kicad flips it internally before going to print. what
it renders to .ps is not the transparent view you see in kicad, but
rather the view from bottom, except mirrored. then, when you put it
toner side down on the board (regardless of whether its paper or
transparency) it is shown correctly.

its just a bit confusing that kicad shows you the board in super xray
vision mode. =)

On 3/4/07, Adrian Bowyer wrote:
> Quoting Zach Hoeken :
>
> > Hmm. I understand what you're saying. However, that would mean that
> > we need separate files for both toner transfer and the photo transfer.
> > (That is a bad thing.)
> >
> > The way I'm suggesting is to have the board and text normal in Kicad,
> > but do the mirroring in the Plot section of kicad... when it gets
> > output to postscript. Then it should be on the right side when you go
> > to etch.
> >
> > You should be able to take that, flip your transparency over (so the
> > toner is on the copper) then do your normal process. Am I missing
> > something?
>
> I think we have one too many flips. Imagine looking down on the board
> from the component side (which is the view Kicad gives you when you're
> editing). Now imagine your transparency with the pattern on under the
> board, with its toner touching the copper. That's what Kicad shows
> you, what you want to print, and what you want then to put on the
> board. No mirror involved at any stage.
>
> Or maybe I'm missing something :-)
>
>
> Yours
>
> Adrian
>
> [staff.bath.ac.uk]
> [reprap.org]
>
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