[Coco] How many still breadboard?

[Gene Heskett]

On Tuesday 07 April 2020 21:31:05 James Ross wrote:

> Gene Heskett wrote:
> > Poor connections on breadboarded stuff drove me to wire wraping 40
> > years ago. Now its almost a forgotten art and I've not used it in
> > years.
>
> Oh yeah – I’ve looked into wire-wrap tools and sockets last year as
> well, but haven't gotten any yet – the sockets seem to be all OLD
> stock (new or used). And some of it seems pricey! Definitely better
> than breadboarding, as I remember experimenting w/ wire-wrapping about
> 35+ years ago.
>
> > Making my pcb's on a milling machine gets the job done.
>
> I’d love to see that thing in a video or pictures!
>
Believe me Jim it gets boring with a mill whose max spindle rpm is 2500 
because you can only move it maybe 3" a minute. A double sided board 
1.5" x 2.5" may be in excess of 10 hours for a 3 photocell encoder. Now I 
have a 6040 mill with a 24k revs spindle. But its bed is junk so i have 
to make a flat pallet for the pcb first, something thats .001" or better 
flat. But with that spindle that 8 to 10 hour slog is about an hour + 
tool changes because it can move correspondingly faster. The trick is to 
remove the copper but not cut into the glass fiber under the copper. Cut 
into the glass, leaving a white gap full of glass dust and you've got a 
dull carbide $10 bit in 5 to 10 minutes. So you trace a very thin line, 
widening it about a thou per retrace until you've enough gap between 
traces.  you don't do that with acme screws, takes good ball screws and 
nuts.  For thru holes, you drill about 40 though into the 62 thou 
material, turn it over and mirror the drill pattern and drill 40 into 
the other side and your holes meet in the center of the board thickness. 
It can be done but you'll wind up inventing gcode to find and register 
the sides.

It can be done faster with chemicals but then you have the disposal of 
all that environmentally VERY nasty stuff. Moral of this story is send 
your art work to OSHPark and get 3 copy's of it back in about 2 weeks 
for about a $12 bill. And they do very nice work.

> -jr

Cheers, Gene Heskett
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