a couple bad 3PDT's

[LucifersTrip]

A friend sent these to me telling me they weren't working and asked me to check em out...I already gave him my opinion, but he wanted a third party's.

[Mark Hammer]

[LucifersTrip]

Thanx...I enjoyed that the first time you posted it.

Though, what my friend wanted was another opinion on what can be inferred by simply looking at the switches.
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Also, In that video, you showed how to solve the problem when a switch stays "open", but not when it stays "closed", which is actually the case here.
I will explain what causes that and how to solve it if anyone is curious.

Edit (since you didn't show the innards of the common 3PDT):
On the standard blue 3PDT switches, the "rocker contacts" on the inside are actually flat, (unlike the banana shaped ones on the black...though, they do work the same way). Additionally, on the black switches, the nubs that are in the "see-saw mechanism" are plastic, but on the blue, many are metal with a small spring that holds them into the "see-saw mechanism".


thanx again

[rousejeremy]

I've experienced the lugs moving around when being soldered on cheap switches, and then becoming unstable. It looks like a lot of solder was applied to those two, that may indicate an iron was on the lugs a little too long.

[Pojo]

+1, the epoxy shows signs of over heating too. Maybe the iron wasn't quite hot enough causing him to keep the iron on the lugs too long. Of course we all know that with these blue cheapies, you seriously gotta be in and out within no more than 2 seconds.

I'm kinda surprised they don't work though, doesn't look like the lugs shifted around yet. But the middle lug on the first switch appears twisted.

[Mark Hammer]

I've gotten switches of the toggle and stomp variety that came with tarnished solder lugs.  I had to go medievel on them with an X-acto knife and produce some hospitable landing spots for solder.  If a person is unfamiliar with those switches, I can see where they might end up applying enough heat to reflow the internal grease OR soften the epoxy holding the lugs in place.

I still recommend opening the switches (if possible) and cleaning the grease off.

[LucifersTrip]

Good...I was waiting for you guys to comment on the epoxy...

I started this thread mainly so newbies could see what a cliche overheated switch looks like.

On these, there's too much solder and there's breaks in the epoxy (which usually means the lugs have shifted). These switches are actually very durable if soldered properly. There's no reason to use that much solder or use anything more than a quality 30 - 40 watt iron for a couple seconds.  Unless, of course, the lugs are tarnished/oxidized as Mark noted....but these were brand new.

Newbie tip: If you don't get a nice joint on the first shot, wait for it to cool, then try again...rather than immediately trying again while it's still hot.

Anyway, guess what happens to the rocker (pink below), when you over heat a lug and it shifts either to the side or inward.  The rocker can't see-saw and you wind up with an always on (closed) connection.

Top pic = normal. Both of the above switches suffered from this problem and were easily fixed by reheating the problem lug(s) and shifting back into place.



One question for Mark. Obviously, the grease was put on there for a reason (reducing friction between nub & rocker to increase life), so probably not a great idea to clean it off completely...but just make sure it's not spread across the entire rocker.  If you need to re-apply a small amount of grease after cleaning, what type of grease is used?

[Mark Hammer]

I suspect the grease is also to reduce chatter by damping rocker contact vibrations.

No idea what kind it is, but after cleaning, I guess you'd need to apply it with a toothpick, or similar.

[italianguy63]

Yeah, I've managed to kill a couple.  I use 3PDT soldering boards exclusively now....  I solder them on fast, and only a couple lugs at a time, leaving time to cool.

Has anybody noticed that the black one are quieter than the blue ones?  Seems when I used blue ones in a Wha, they always squeeked or clicked (annoying).  Maybe because the black ones have some plastic components in them?

MC

[Jdansti]

I always put a very light coat of flux on the lugs with a flux pen before I solder. It only takes a second to get a good solder joint.

[duck_arse]

back when I was working near some machine fitters, they was alway replacing "wear kits" in various machines. the kit came w/ o-rings and seals etc, and a small tube of silicon grease. festo call theirs "Spezialfett". I've often wiped it on plastic gears and stuff, it might be the thing here too.

[pinkjimiphoton]

i got a bad batch of 10 recently, i had 4 bad out of the batch. i contacted the vendor, and he made it right.
it wasn't overheated... in 3 of the 4, the switches were intermittent, and the 4th one, when socking down the nut, the threaded part actually pulled right out of the top!