Riveting pcb holes - engineering type input sought!

[HankMcSpank]

Hi Jonathan...thanks (as ever) for the input.

Truth be told, I don't trust Chinese fab houses.

This is fairly low run....I'm probably talking 40pcs maximum per annum .....it only takes me about 15 minutes to mill 10 nested copies of my pcb layout, therefore just over an hour to mill one years supply of the pcbs needed!

Actually, I think I've found the tool I need....

http://www.mouser.com/ProductDetail/...8SqT5kVQ%3D%3D

which crimps these eyelets.....

http://www.mouser.com/Search/Product...tP4fbZOg%3d%3d (1/8" ....they'd probably do for M3)

The rivet press for riveting thru hole rivets for PCBs costs about £500!

Re using a lathe...I don't have one, & that sounds time intensive (& I'm trying to get the time down to build one of my widgets....it already takes me about 1.5hrs (I'd rather use something already available & cheap as chips...hence looking at brass/copper rivets/eyelets) ....also I suck with a lathe

(Incidentally, I've found a cheapskates method for PCB stencils....from drinks cans! https://www.youtube.com/watch?v=JWUJtmgh55M .....except he's etching, that could readily be milled)

[cropwell]

I read your requirements about position of the hole and I thought maybe a steel M3 riv-nut could be soldered into the PCB. The one I have are 4.7mm OD and 8.7mm long. I have the mandrel for the setting tool, but they are fragile and hard to come by, but it sounds as though setting them in the PCB would not be an option anyway.

[mekanik]

Looks like the best option is going to be soldering to the board, i would get some 2 or 3mm brass plate cut off a strip drill and tap several holes and the cut it to a length that dives you a reasonable surface area, then solder it to the board.
You could do the drilling on your cnc and knock off a bath in a reasonable amount of time.
Regards
Mike

[Boyan Silyavski]

Any leather eyelet pliers will do the job and if they don't reach, then refabricate something similar with longer reach from them . If it was me i would simply instant glue each side a washer. If the glue is good it would stick forever.

Plus, nobody could convince me that the PCB eyelet which they sell for 10cents is not in fact leather eyelet.

[magicniner]

I have the mandrel for the setting tool.

Whilst you can buy and use a Riv-Nut setting tool all you need is a flat steel bar with a hole through it and roughed up a bit on the side presented to the Riv-Nut head, preventing slipping when setting.
Use a bolt or bit of threaded bar through the flat bar and fully engaged with the Riv-Nut threads.
With lubed washers & well lubed nut on top, tighten nut whilst ensuring the bolt doesn't turn and set the Riv-Nut to the tension or height of your choice.
I use 60% Moly paste for the lube as it gives the best possible friction reduction and thus translates as much torque as possible into tension.

- Nick

[mekanik]

My idea was to solder the insert, removing the serations means you can have a smaller hole in the board so the board is stronger. the inserts could be machined to practically any size you want.
Regards
Mike

[magicniner]

Brass bar stock is cheap enough, I suspect you could knock out a few dozen in an hour once you have the tooling and a procedure set for your lathe.

The topic title does lead one to think down a riveting specific mechanical route ;-)

[mekanik]

Brass bar stock is cheap enough, I suspect you could knock out a few dozen in an hour once you have the tooling and a procedure set for your lathe.

The topic title does lead one to think down a riveting specific mechanical route ;-)

You are correct the OP was looking for an off the shelf solution and your method is proven so it looks like the best choice in that regard, have my doubts about the rivet method only because of the wall thickness of the hollow rivet, the method i offered puts no strain @ all on the PCB. if OP sends me some of the inserts i pointed too i will gladly machine them to the size required.
regards
Mike