Homebrew PCBs

I've been doing a lot of 'thinking' on how I'm going to consistently pass a
PCB through the printer.  It quickly became obvious after reading Volkan's
'align with the PCB sticks' technique that an easier method would be nice to
have.

Volkan's technique will probably be better for one-offs, but I'm looking for
consistent results for multiple identical prints.  So, I've come up with
this basic design:
http://www.xavierkamial.com/images/Epson%20C84%20chariot.JPG

Start reading the pic from the bottom-up, I drew it as I was constructing it
in my head.

The CHARIOT will be a permanent unit, it will be used all the time to pass
PCBs though the printer.  The PCB HOLDER has to be fabricated for each
individual PCB, unless they share alignment hole pattern, then good for you.
Consider this step equivalent to the 'tooling charge' that PCB fabricators
charge you for an order.

One issue that will have to be addressed is double-sided alignment.  QCAD
has an alignment offset, so I can compensate quite easily.  Others may have
a problem printing the bottom side 'exactly' over the top side.  Maybe using
2 PCB HOLDERs might be an option?

The nice thing is that you can whip out PCBs with little effort once the PCB
HOLDER is fabricated, making error-correction a much easier task.  (I was
thinking of Chris when I wrote that last sentence)

Robert
:D



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

Overly complicated.
We worked out how to solve this problem ages ago, with no different PCB  
holders to make and no holes to drill.

You simply stop at that bottom plate, stick a strip of PCB material to the  
leading edge that has a mark in the center.
Then you mark the edge of your pcb about in the center as well, with a  
pencil or a knife or whatever. You simply push the PCB against the  
straight edge and align the two center marks. If some sort of force is  
required to hold it in place it is easy to either stick it down with tape  
at the edge or build some sort of clamp.

Then you print, take the PCB out, dry it, put it in again other side  
around taking care to alignmen the two center marks.

If you really insist on having those overly complicated pegs and having to  
drill holes into the PCB you could simply make a row of holes like 1cm  
apart in the bottom plate, and number them. Then you could set the pegs  
for different board sizes quite easily. But i can't see why you'd want to  
do that other than maybe if you cnc drilled the whole board before  
printing.


ST



On Tue, 30 May 2006 04:58:34 +0200, Robert Hedan  
<robert.hedan@...> wrote:

> I've been doing a lot of 'thinking' on how I'm going to consistently  
> pass a
> PCB through the printer.  It quickly became obvious after reading  
> Volkan's
> 'align with the PCB sticks' technique that an easier method would be  
> nice to
> have.
> Volkan's technique will probably be better for one-offs, but I'm looking  
> for
> consistent results for multiple identical prints.  So, I've come up with
> this basic design:
> http://www.xavierkamial.com/images/Epson%20C84%20chariot.JPG
> Start reading the pic from the bottom-up, I drew it as I was  
> constructing it
> in my head.
> The CHARIOT will be a permanent unit, it will be used all the time to  
> pass
> PCBs though the printer.  The PCB HOLDER has to be fabricated for each
> individual PCB, unless they share alignment hole pattern, then good for  
> you.
> Consider this step equivalent to the 'tooling charge' that PCB  
> fabricators
> charge you for an order.
> One issue that will have to be addressed is double-sided alignment.  QCAD
> has an alignment offset, so I can compensate quite easily.  Others may  
> have
> a problem printing the bottom side 'exactly' over the top side.  Maybe  
> using
> 2 PCB HOLDERs might be an option?
> The nice thing is that you can whip out PCBs with little effort once the  
> PCB
> HOLDER is fabricated, making error-correction a much easier task.  (I was
> thinking of Chris when I wrote that last sentence)
> Robert
> :D

> -----Message d'origine-----
> De : Homebrew_PCBs@yahoogroups.com 
> [mailto:Homebrew_PCBs@yahoogroups.com] De la part de Stefan Trethan
> Envoyé : mai 30 2006 03:50
> À : Homebrew_PCBs@yahoogroups.com
> Objet : Re: [Homebrew_PCBs] Epson C84 PCB chariot
> 
> 
> Overly complicated.
> We worked out how to solve this problem ages ago, with no 
> different PCB  
> holders to make and no holes to drill.
... But i can't see why 
> you'd want to  
> do that other than maybe if you cnc drilled the whole board before  
> printing.
> 
> 
> ST


'Cause I have the recall capacity of a sparrow.

Robert
:D

Robert,

I think I see an advantage to what you are describing though.  You 
are planning on making circuit boards in quanities greater than one 
or two, not just one-offs.

If that is the case, then making special carriers (I think you are 
calling them Chariots), would make good sense.  You could 
standardize the carrier board to one specific size.  This would make 
for very consistant locating in the printer.  

If you make that carrier plate with removable pins, you could build 
it so that you could use one carrier plate and by re-arranging the 
pins, have it adapt to all your PCBs.  You could also very easily 
design it with a center mark and a straight edge as a stop for the 
method Stefan is referring to and have the best of both systems all 
in one Chariot. 

Chris
 









--- In Homebrew_PCBs@yahoogroups.com, Robert Hedan 
<robert.hedan@...> wrote:
>
> > -----Message d'origine-----
> > De : Homebrew_PCBs@yahoogroups.com 
> > [mailto:Homebrew_PCBs@yahoogroups.com] De la part de Stefan 
Trethan
> > Envoyé : mai 30 2006 03:50
> > À : Homebrew_PCBs@yahoogroups.com
> > Objet : Re: [Homebrew_PCBs] Epson C84 PCB chariot
> > 
> > 
> > Overly complicated.
> > We worked out how to solve this problem ages ago, with no 
> > different PCB  
> > holders to make and no holes to drill.
> ... But i can't see why 
> > you'd want to  
> > do that other than maybe if you cnc drilled the whole board 
before  

> > printing.
> > 
> > 
> > ST
> 
> 
> 'Cause I have the recall capacity of a sparrow.
> 
> Robert
> :D
>