Is there a solderless connector for tiny connections on small switches?

August 30, 2015 7:42 PM

The pic of the switch described in this question is here. I have these 16mm diameter switches with these tiny little contacts, with tiny little holes in each. I have to connect wires to all of them, and soldering onto them is really tough because they're so little and so close together. I have a bunch of them to do so I was wondering if there's some sort of ultra-tiny female spade solderless connector that exists, or some other sort of solderless connector that would allow me to skip all that soldering. If so, where could I buy them?

If I have to solder them then I also have to goop them with liquid rubber to make sure I get no shorts, etc. Altogether a real pain, and they don't seem real robust so I'm kind of concerned that they could break off if I move the soldered-on wire too much. Any help? Thanks!

Tom

posted by Tom Blees to Technology (10 answers total)

Sure, google "female spade connector". I'd check how wide the contacts are so you get female connectors that are the right size. They seem solderable in that photo but maybe it's enlarged versus the real thing.

As for preventing shorts, slip some heat shrink tubing over the wire before you connect it, connect it, slide the tubing up and then apply heat to shrink.

Or it looks like some of the female spade connectors come with insulated boots so then you're set.
posted by GuyZero at 7:53 PM on August 30, 2015 [1 favorite]

If that button is what I think it is, these are what you're looking for.

If it's not, we'll probably need measurements or a link to a spec sheet. The search term for the type of connector you want is "female disconnect," but size is paramount.
posted by eschatfische at 7:56 PM on August 30, 2015 [2 favorites]

Digikey labels them as "quick connect", select female and specify the width of your tab (on your switch).
posted by Behemoth at 8:21 PM on August 30, 2015 [1 favorite]

I'd still recommend soldering them. My soldering skills were very suddenly much, much improved when I switched to a eutectic solder. Eutectic solders don't pass through (or go through it very quickly) the crystallizing period that allows bad joints in regular solder.
posted by builderofscience at 8:25 PM on August 30, 2015

Soldering is really the right way to do it, I'm afraid. Those are actually gigantic huge connections compared to the surface mount stuff everyone is using these days. Just take them to a local hackerspace or something if you need help. Practice a bit and it will be easy.
posted by ryanrs at 8:28 PM on August 30, 2015 [1 favorite]

Oh, and yes, I would absolutely solder. Looping each wire through the hole and twisting it around itself prior to soldering will be way more reliable than the connectors. And you'd have to crimp the connectors to a wire regardless, which doesn't save you all that much time over soldering. Use heat-shrink tubing big enough to fit over the tabs on the switch.
posted by Behemoth at 8:29 PM on August 30, 2015

Insulated crimp connectors are available. Check the size.
posted by H21 at 8:32 PM on August 30, 2015

I hate liquid rubber. If it's low voltage, I have been known to use hot glue for insulation and strain relief.
posted by Standard Orange at 9:45 PM on August 30, 2015

So just to clarify, those terminals are technically specified as "solder lug" and are designed to loop a wire through for soldering. Having the right gauge wire and making sure your soldering technique is good will help it go faster but the only way to make it less onerous is batch processing (eg, strip all wires, cut all heat shrink to the same length, put on heat shrink and loop wire, do all solder joints). If you really have a zillion to do it can also help to drill a bunch of holes into foam or wood to hold the switches upright to solder.

That's a low voltage switch and I wouldn't hesitate to just pot everything in hot glue when it's done (just be sure it's what you want, because going back is super annoying).

You might be able to find mini crimp connectors but solder lugs are usually so flimsy it's a pretty narrow sweet spot between "snug enough to not fall off later" and "so tight it induces column buckling when you try to slip it on."
posted by range at 5:32 AM on August 31, 2015

Response by poster: Many thanks to all. One of the problems, I think, is that I was trying to use a wire that's too heavy guage for what I need because i happened to have a roll of it available, so it wouldn't fit through the holes. I'll buy a roll of smaller guage and it should work fine to solder, I guess, since it's just a 12V system for some small lights.

T
posted by Tom Blees at 5:53 AM on August 31, 2015