Homebrew PCBs

On 16 Oct 2017 01:45:51 +0000, you 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. 

Hmmm, kinda been there, did that, then did other things instead.
I think the previous poster's comment about slotted rivets is quite
correct.  I had a story from someone about the regular rivets not
working in the long run.  Solder has to go to the outside of the
rivet, and that has to be soldered to the land on both sides.  Then I
think it'll work.  You do have to check both sides of the rivet.
>
>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. 

I actually have one.  Fortunately, it matched the rivets I bought.

>If you have access to a small lathe it may be possible to make your own. 

From the size involved, you'd want almost a watchmaker's lathe,
smaller will be better here.  The seat for the rivet is a simple
stepped cylinder, with enough of a center to keep the rivet centered.
The hammer part is a bit more tricky.  It needs to be dished but only
in a ring.  A standard conical punch shape would cause the rivet to
split, but not fold over against the PC material.  Look at the much
larger rivet seating tools to see.  

Once you make the tool, you'll want to harden it.  Tool steel is
recommended.

>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. 

A very light tap would work well.  You'll find that the rivet takes a
lot of room on the board, needing a substantially sized hole.  It'll
limit the size of the parts you can use.  I ended up using copper
rivets (available locally).

>If you still have to tools then getting more rivets/grommets/eyelets should be easy.

You'd almost do as well with stake in terminals.  It would be a much
larger board with somewhat difficult ways of doing vias.  One
technique is to treat the whole board as single sided as far as parts
leads is considered, then stitch the top and bottom together with
thing gauge wire (say #26).  You then solder on both sides, clip the
unwanted parts, and you have vias.  

Doesn't allow you to do through holes well on things like parts leads,
but does work.

Lots depends on the size of the parts, the number of vias and whether
or not you can do a via without a plated hole, and if your design can
tolerate all through leads to be effectively single sided.

Harvey

>
>Mike