Homebrew PCBs

For your problem to convert to Gcode from gerber, there are three ways:
-pcb-gcode (works ok but in Eagle)
-export to DXF then into Cam package like LazyCAM with Mach3
-some commerical package made to CNC mill out pcbs from gerbers (forget the
name, was on pcb-gcode group)

On Fri, Nov 13, 2009 at 11:21 AM, designer_craig <cs6061@...> wrote:

>
>
> I had the same idea last spring and purchased a 405nm laser diode with
> holder/lense and some Riston film off ebay. I added a heat sink to the
> holder and have driven it up to 110ma. At that power level it will burn
> through paper, so I have no doubts that it should harden the photo resist. I
> did some initial crude calculations based on the Riston data and estimated
> diode power that led me to believe it would be possible to write a .001" dia
> spot at 80"/sec.
>
> My initial plan is not to raster scan the board but to vector draw the
> pattern using my Bridgeport mill that is currently being converted to CNC. I
> will need to write some code to convert the Gerber photo plot file to a
> G-Code file to drive the mill. These files are very similar, the Gerber
> format being an offshoot of the G-code format. Since I plann on using a
> fixed spot size, wide traces will need multiple passes as will donuts etc.
> This all has to be coded in the conversion program.
>
> Currently I am working on the mill's CNC conversion and have not done any
> testing on the direct exposure part of the project. It will be a couple of
> months before the mill is ready for PCB testing.
>
> Issues to be resolved:
> 1.Is the exposure of photo resist linear ie. is high power UV for a short
> time the same as low power UV for a longer time.
>
> 2.Code to make multiple passes for trace and shape widths from the point
> gerber data.
>
> 3.How to get a .001" dia round spot. The laser diode output is not round.
> How to measure the spot dia.
>
> 4.How long will it take to expose a 3'x5" board?
>
> Craig
>
>
>  
>


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