PSA regarding Tayda Alpha rotary switches

[Govmnt_Lacky]

Just a heads up to ALL of my fellow 'bean builders....

I recently discovered that the Alpha-style rotary switches sold by Tayda have a common issue. Some of you may know this already but I figured I would post about it.

Apparently, if you decide to tighten the nut down on the rotary switch a little too tight (and I mean A LITTLE)... it will cause the internal rotating disc to miss its contact with the common lug. I have run into this SEVERAL times with their 3P4T and 2P6T rotaries as well as a few other styles. Often times, you cannot loosen the nut and get the proper connections back  AND... sometimes it will work great when turning the shaft CCW but you will miss contacts going CW.

SOLUTION: ALWAYS use the little guide pin (plastic) on the side of the rotary. Drill the small hole for the alignment (and anti-rotation) pin and just tighten the nut down enough so that it is "snug" IT does not take much to overtighten these.

I used to just snip off the alignment pin on the side and tighten the nut so the switch would not rotate. NOT ANY MORE! You can do this with metal pots but these plastic rotaries will not take the pressure when tightened.

Just a heads up! 

[muddyfox]

Thanks G.! Good to know (as I'm just about to start my Meatball build)!

[lars]

That's a good rule of thumb in general. I was always lead in the direction that those pins are just something you're supposed to snap off immediately. I recently completed my first build where I left the pins on my regular pots, and drilled the little holes for them.
What a difference!
You can tighten them down without the bodies rotating, and the whole build feels more solid. It's especially good for builds that the pcb relies on the potentiometer legs to hold it in place. From now on, I'm not snapping off those pins despite the fact that most build docs recommend it, and most people do it. Just drill the extra little holes! It takes like 2 minutes total and a smidgen of extra planning on your layout.

[jimilee]

Rej always does this, but do you have any photos of your builds with the holes? I'm curious about the aesthetics. Some of us (me) aren't quite the level he is.

[flanagan0718]

Rej always does this, but do you have any photos of your builds with the holes? I'm curious about the aesthetics. Some of us (me) aren't quite the level he is.

+1

[Govmnt_Lacky]

...but do you have any photos of your builds with the holes? I'm curious about the aesthetics.

No pictures to date. Primarily, I have run into the problem when doing my XP ALL builds. I have used the same rotaries in my recent Lovetone builds but only ran into this problem 2 times. It seems like I see this problem (or.. SAW this problem) every time I used one in the XP builds. The last 5-6 XP ALL builds I did where I didn't drill the alignment pin hole had issues.

I will say that you need to use a rather large knob to cover the hole.

[jimilee]

...but do you have any photos of your builds with the holes? I'm curious about the aesthetics.

I will say that you need to use a rather large knob to cover the hole.

Two things, great sig right there. And covering was what I was curious about. I could cover it with the decal I suppose. Not crazy about larger knobs, but if it's a selector, it would probably be larger anyway.

[davent]

Not sure about the Alpha switches but at least with pots and Hammond enclosures you can drill deep to engage a shortened nub, without drilling through the enclosure.

[Govmnt_Lacky]

And covering was what I was curious about. I could cover it with the decal I suppose. Not crazy about larger knobs, but if it's a selector, it would probably be larger anyway.

You could absolutely cover the alignment hole with a decal. The hole could also be driller just before going completely through the enclosure as Dave states but... even if you go all the way through... the pin does not stick out of the face of the enclosure so you could cover with decal or the likes.

[GrindCustoms]

Great tip there Greg, was wondering why my ZPDLX was acting strange some times.

Might just loose the nut to see if it helps, orientation hole being already drilled.

Been drilling all my pot nub holes for the past 2 years, the 2 minutes added to drill the enclosure is totally worth it.

In my optics of pedal building, reliability always win over aesthetics.

[joegagan]

Not sure about the Alpha switches but at least with pots and Hammond enclosures you can drill deep to engage a shortened nub, without drilling through the enclosure.

i use a couple round head dremel cutters. here is an alpha with the tab in my modded BBE wah