I have just received a RC transmitter PCB I designed and ordered, whose brains are to be an Arduino Nano. Unfortunately, the PCBs thru hole diameters for connecting the Nano are too small. All other through hole sizes are appropriate.
In an attempt to rectify the issue, I have a couple ideas:
Purchase headers with the standard 2.54mm pitch, but with a smaller pin diameter/width. I skimmed Mouser and could not find anything of the sort, however I am very new to this and may have missed a product. Does anyone know of a product of this variety?
Sand my 2.54mm pitch, 0.64mm width headers, to fit in the 0.76mm thru holes that exist on my PCB. I am not sure whether sanding will be a detriment to pin conductivity. Has anyone had to do this before, or have any strong opinions against doing this?
Drill out the holes. This is my last resort, as ill need to purchase some/a drill small enough for the job, and I don't want to sacrifice a pad dislodging from the board.
I am looking for any opinions/thoughts from those of you who have needed to do something similar in the past. Any information would be greatly appreciated.
(1) above was possible. There were machine-pin sockets with small diameter pins that could accept larger diameter headers, but I haven't seen them in forever. If it helps, Mill-Max made them.
I would not drill the holes out unless you can’t avoid it as you will loose the through hole plating .
I’ve used a needle file on pins with good success
If you have plated thru-holes and a decent soldering iron tip, you can just put the nano in to the footprint on the board as best you can and then solder the pin directly to the pad without it going all the way in to the hole.
This is not a great solution, as your nano will be hovering above the PCB and mechanically less stable, but it is the cheapest and fastest way.
Actually there are tapered reamers made for just such a problem. I don't recall where we got the set from, nor the brand name. But they quickly fixed the error and left the plating still conducting electrically.
Addition: It occurred to me that I might have kept the set. Sure enough they were on one of the tool boxes. A set of 6 tapered reamers from hair size to perhaps 1/16 inch. All tapered. Unfortunately, there is no name on the reamers or on the plastic holder. Sorry.
Cannibalize an old UTP or telephone cable, pull one of the solid wires from it, remove the insulation and start soldering the wire in the hole of the nano, cut off at 2cm and solder in the next piece.
That way you create you own thin "poor mans pinheaders".
I think you have to make a new board.
The through hole diameter must exceed the diameter of the pin of the connector, and leave a certain margin. The minimum diameter that can be achieved through the line hole is limited by drilling and plating techniques. For us, the through holes tolerance is +/-3 mil.
Thanks, John. Broaches is the correct name as they use a scraping of the hole to enlarge it while reamers actually have a cutting edge to remove material. Identical to my package, except the color of the plastic case. And they will scrape a bit of the plating to enlarge the opening. Soldering the wire will complete the circuit if all the plating and graphite is removed.
