Homebrew PCBs

The pins that I use come from female header strips, and sell for about 
0.90 USD for 3 pieces of 40 pin strips, including shipping. Example: 
http://www.ebay.com/itm/3-PCS-Strip-Tin-PCB-Female-IC-Breakable-40pin-Single-Row-Round-Header-Socket-New-/361872902978?hash=item54414e4b42:g:2wwAAOSw7hRWQCzj. 
I use my heat gun to soften the plastic, ad push the pins out from the 
tail side.

Using these pins eliminates all the need for special tooling, and they 
are cheap. In my early days in the Aerospace industry, we used eyelets 
to repair pulled out holes in plated through boards. There are some 
considerations to using them, and they were eventually banned from 
military systems, except under very special circumstances. It was found 
that over time, the solder joints between the pad and the eyelet would 
crack. This situation could be improved by using funnel head eyelets and 
flaring the backside. This allowed the solder to make a fillet with the 
underside of both top and bottom of the eyelet. Flaring the eyelet 
without breaking it was somewhat problematical. The tooling had to be 
just right, and the force sufficient to make sure that the eyelet was 
firmly swaged to the board, with no play.

The pins that I propose can be used in either of two ways. The solder 
tail can be stuck right into the hole, and the tail soldered first, with 
the top pad then soldered to the shank of the pin. The other way would 
be to make larger holes, if the pads permit it, and push the shank 
through the hole and solder it to the bottom pad, and the collar of the 
pin then soldered to the top pad. This does require that the top pads be 
a bit larger. The advantage to the second method is that the socket pins 
will sit flat on the board, and will always be in line without 
adjustment. This assumes that one can drill the socket holes in a 
straight line. Once in place. the solder tails can be broken off to get 
them out of the way.

Harvey
On 10/15/2017 6:45 PM, mbushroe@... [Homebrew_PCBs] wrote:
>
> I considered using these in the past but never actually bought some. I 
> believe they are normally called pcb rivets or hollow grommets, or 
> eyelets. Of all things, Walmart sells a bulk pack of 200 for $6.
>
> Finding the right grommet setting tool could be a bit harder. A hand 
> operated press with top and bottom dies will probably run over $100. 
> If you have access to a small lathe it may be possible to make your 
> own. Harbor Freight sells a watch case press that possibly be modified 
> to either take you home made dies or machine the parts that come with 
> it. If you still have to tools then getting more 
> rivets/grommets/eyelets should be easy.
>
> Mike
>
>