Homebrew PCBs

Metal etching is on topic.

What about a stepper motor? 200 steps per revolution. Or if that is not fine enough, bring that down with toothed belt and pulleys?

Steve Greenfield AE7HD


--- In Homebrew_PCBs@yahoogroups.com, "Rick Sparber" <rgsparber@...> wrote:
>
> This has been a favorite problem of mine for a long time. 
> 
>  
> 
> It is standard practice to engrave the outside diameter of a cylinder with
> tick marks and numbers in order to make a graduated dial. I have done this
> by laser printing, mirror image, to clear plastic and then bolting it on the
> OD with the toner on the inside:
> 
>  
> 
> http://rick.sparber.org/Articles/CD/CDM/d.pdf
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>  
> 
> It is fairly rugged but not as nice as engraving. I've always thought that
> chemical etching would be idea. 
> 
>  
> 
> I'm not interested in super expensive methods or ones requiring more than
> average skill. Sure CNC can do this task, so can a laser cutter. Maybe
> Wal-Mart sells them. No fun there.
> 
>  
> 
> One idea that I just thought of uses a previously engraved dial. I would
> turn a cylinder with the same OD as the dial. Then I would fill the grooves
> in the dial with softened paraffin wax and strike off so the rest of the
> surface is wax free. Then I would chill this dial while heating the cylinder
> to be etched. By rolling them together, I hope to transfer the wax from dial
> to cylinder. If that works, the etching process should be easy. I realize
> this generates raised features rather than recesses but that might actually
> be better. Since something like this works for printing, maybe there is
> reason for hope here.
> 
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> 
> Has anyone tried this? Any warnings or suggestions?
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> 
> Thanks,
> 
>  
> 
> Rick
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