First, kudos. Nicely done.
Second, smart idea about the extra diode NOT on the main board.
Thanks, and thanks.
Third, why the heck did you put the white washer on the inside?
The washer isn't needed on top as the finish is extremely durable. But in playing around with the height of the switches, I found that the washer in combination with the nut and the lock washer ends up being the perfect height. So I just tighten the nut down over the washer, slide on the lock washer, and then each switch is exactly the same height.
There's no mechanical downside, so I'm happy with it. Using a second metal nut instead of the plastic washer might look nicer, but no one will be looking inside that much.
Fourth, I've become convinced that at least SOME of the switch failures from stompswitches occur when there is sufficient heat buildup across contacts during soldering to cause reflow of the otherwise thick goop inside the switch. That goop would normally just be sitting on the middle pivot point of each rocker contact inside the switch so as to hold the rocker contact momentarily until the two switch halves are combined and the side tabs squeezed. When excessive heat is applied, the goop seems to flow outward from the central pivot point along the rocker contact, blocking contact with the side lugs.
Now, somebody must have figured out a way to reliably solder these things in large quantity without causing this form of switch failure because, let's face it, places like Dunlop and Fulltone could not continue to exist if they couldn't avoid such switch failures.
But these places are cranking out larger numbers of such pedals, and more importantly, only use a single switch per pedal most of the time. So, I'm wondering. Not to underestimate your fabrication chops (which clearly exceed my own), but I gather you aren't wave soldering in some Chinese factory, so how the heck are you going to assure that you don't find yourself with a board that has itself secured to three stompswitches, and one of them is bad? I can easily see the advantages of mounting the switches to the board, but how does a guy who turns out units in the dozens, rather than thousands, arrange to have soldering consistent so as to avoid such production issues?
Again, I'm not questioning your chops. This is more of a practical "how do YOU do it?" sort of question.
I'm very far from wave soldering in a Chinese factory. I'm using 25W and 35W Weller pencil irons with a Radio Shack iron holder on my kitchen table. Though I might order some Chinese takeout for lunch as I work, that will be as close as I get.
The answer so far is just trial, error, consistent soldering approaches, and really nice Belden 22AWG silver stranded wire. I strip each wire just enough to go inside the lug on the switch, and then use a really hot iron very very briefly, causing the solder to flow. I use really thin solder for this, so it flows quickly but not a lot at once. Doing it this way, each lug is only touched once for a very short time. I get nice shiny solder joints but the switch doesn't get that hot.
I tried this with some 24AWG wire from smallbear, and while it was nice for general purpose wire, in the Triad (small spaces, high gain) it was microphonic and the smaller gauge had more space around the wire inside the switch lugs. The Belden 22AWG isn't microphonic and it exactly fits inside the lugs, so there's more metal to metal contact and it takes less solder as no solder is needed as glue/filler.
I've had one of these blue switches fail, in one of my first prototypes where the switch in question saw repeated resoldering. The plastic holding the lug went soft and the lug could move around. So I think your concern is absolutely correct, but so long as I'm consistent and quick I don't foresee problems.
(well, eventually I will have pedals returned to me to have switches replaced due to mechanical wear and tear. That's inevitable)
