Re: gEDA-user: gEDA mounting hole for screws

[joeft <joeft@xxxxxxxxxxxxx>]

Stuart,

Aside from the mechanical tolerance issues brought up later in this 
thread, the board fab may have an influence.  You don't indicate whether 
you are starting from the drill size or finished hole size.  .002" of 
clearance may not be enough.  The fab vendors we use give a few mils 
tolerance just for the drill, and I customarily use .006" for plating.  
I would start with at least .008" clearance when choosing the drill size.

Joe T

Stuart Brorson wrote:

> > On 12/6/05, Stuart Brorson <sdb@xxxxxxxxxx> wrote:
> >
> >    
> >
> > > I don't know if any pre-made holes exist.
> > >      
> > http://www.luciani.org/geda/pcb/pcb-footprint-list.html#Hardware
> >    
>
> Thanks, but I meant hole symbols for gschem, not hole footprints for
> PCB.  Anyway, I am happy to see pre-made footprints for hardware
> on your site!  
>
> Just a random question for the anybody:  For, say, an 1/8"
> through-hole, what kind of tolerance factor do you add for safety?  I
> make my 1/8" holes 0.127", but 0.002" seems kinda tight.  What's the
> recommended slop factor for mechanical mounting holes? 
>
> Stuart
>
>
>