Homebrew PCBs

Hello,

Snips, inserts below...

>In Homebrew_PCBs, "Dave Mucha" <dave_mucha@y...> wrote:
ST>> How long would it take to get the 
>>drilling software running if my 
>>layout software produces excellon drill files?
>
>For an fast programmer and a fixed file type and a fixed output 
>code,this could be pretty fast.  couple of days to a couple of weeks.

I'd say a few hours; a day, Or two. MAX.

ST>> How long would it take to get the software running, and roughly 
>>adjusted for solder paste dispensing ?

>To adjust the software, I think it would be a matter of a few 
>boards, or a dozen pads.

Yes.

>The key is to dispense the EXACT same amount from a new tube as from 
>the middle and the end.

Ya think so? IMO, it is WELL proven--by the success of boards using 
hand applied "lines across tssop pads", squiggly and anything but 
exact!-- that close enough IS close enough... 

And the machine will repeat better than many humans dispensing 
manually. (This is not a slam on the machines. The human "servo" 
system is incredibly accurate; once "tuned" by practice...)

ST>>to estimate but i need to know if it is like "oh yes, that would 
>>be simple, I know how I would solve that" or "that's tough, nobody
>>has tried this before".

Yes, that would be simple. But I've been "into" CNC for decades...
 
>I see the simplicity... <Snip>then rate of movement would determine 
>quantity of dispensing.

It's still dots. Or steps of the plunger movment, if we're using the 
stepper based plunger. FWIW, the EFD dispenser designed for solder 
paste uses a leadscrew technique. BUT they put it in the housing of 
the unit, and use a flexible plunger to transmit the linear motion to 
the handpiece. like a LINEAR, instead of rotating, foredom tool...
(You can learn a lot from patents<G>)

>My bottom line on the idea is to build the CNC driller.  that 
>machine will work now, for software that is available now.  the 
>paste dispenser will be an add-on for that by the time you are done 
>building.

Yes. Or buy one from me for 500-1000 bucks... (See my next post)

>Who knows, Ballendo may offer this as an option on his machines 
>pretty soon !

Yes. Who knows...<G>

Ballendo