PCB milling machines??

[Tim Ressel]

I haven't had problems with shorts left on the board from the routing process,
but I do an inspection under a microscope with trusty exacto knife in hand. Bits
for the LPKF cost US $41 a piece!!! But they last quite a while. Tool height on
the LPKF has not been a problem, I set it once, and it stays okay for a long
time.

All in all, I'd say that PCB routers are groovy (pardon the pun) if you really
need one, or happen to have one around. But for most stuff, a PCB house like AP
circuits is a better choice.

Tim Ressel--Hardware DQ
Hewlett-Packard
Verifone Division
916-630-2541  
tim_r1 at verifone.com 



> ----------
> From: 	jhaible[SMTP:jhaible at debitel.net]
> Sent: 	Sunday, August 01, 1999 12:18 PM
> To: 	Synth-DIY List (E-mail)
> Subject: 	Re: PCB milling machines??
> 
> > > I was paging through Electronic Design and saw a couple of ads for
> desktop
> > > PCB milling machines which basically goes from Gerber to drilled PCB by
> > > milling away copper and drilling holes.  Has anybody used these or know
> > > anything about them.
> 
> Terrible stuff, if you're asking me.
> I know because I spent a lot of time looking for shorts on boards that were
> done that way.
> You always have the problem of adjusting the height of the tool, the board
> never being
> perfectly planar or even resonating at certain rotation speed of the tool.
> So you end up
> either removing too much copper - or the contrary. We used to look for
> shorts that were
> caused by copper connections that were too tiny to see them - decide which
> traces are
> shorted, and then burn away the connection with a strong current source.
> A mere nightmare.
> 
> JH.
> 
>