Installing pots

[acehobojoe]

I'm not sure if I am understanding these pots right. They have a little metal thing on the left side, and when I screw the nut onto the top, they make it slanted. Do you know what I'm talking about? I guess a little detail on how some of you put in pots with knobs would help.

[Renegadrian]

just take your favourite pliers and take the MF off! 

[rutabaga bob]

I believe you're referring to the little tab that prevents the pot from turning when you tighten the nut.  Most folks just snip it off with some heavy-ish diagonal cutters, or snap it off with pliers.

[acehobojoe]

Alright thanks. That's all I really needed to know.

[Jdansti]

What everyone else said. It's designed to go into a small hole next to the mounting hole to keep the pot from turning. This usually doesn't look good on our pretty stomp boxes, so most of us break them off. A good place to use them would be if you had a chassis and a cover plate that attached onto the chassis like some amps have. The cover plate hides the little hole.

[Mark Hammer]

Let's just say it is the sort of feature that the majority of us tend not to plan around in enough detail to actually make use of.  You will see it used, however, in things like amplifiers, where the pots might be mounted on a piece of folded sheet metal, and only the shafts protrude through the legended control panel on top of that.  The sheet metal will be punched in a press, rather than drilled, and all the holes, both bigger and smaller, will be perfectly lined up.

Trying to make use of the little tab when you're machining a 1590BB on your home drill press is a pain.  Easier to just snap the tab off, and take a few extra moments to line up the pot the way you want, and hold it in pace while you tighten the nut.  If you were cranking out practice amps like sausages, you'd want some way to get all those thousands of pots lined up perfectly to cut down on production/assembly time, and you'd be sure to take advantage of the tabs.

[nocentelli]

keep the snapped off tag - it wedges perfectly down a split shaft pot to hold it's shape if you use set screw knobs.

[Tall Steve]

keep the snapped off tag - it wedges perfectly down a split shaft pot to hold it's shape if you use set screw knobs.

+1

I am in that situation now. Thanks for the tip!

[Heemis]

In most of my early builds I snapped off the tabs, but eventually the pot WILL come loose, unless you use some kind of lock washer or loctite-like product.  I started drilling the holes and never looked back.  If you use large enough knobs, you'll never see the hole... Even with smaller knobs it's not that noticeable.

If you do decide to join the dark side, I've found a 7/64" hole does the trick.   

[JustinFun]

Alternatively, you can actually use it for the purpose it was put there for. Drilling a hole for the tag is easy enough and any medium-sized knob will cover the hole completely.

There are few more annoying things in a diy stomp box than pots which come loose and lead to sloppy, moving controls. It's also an obvious point of failure as pots twist round and ground on other connections or wrench leads off the tags. A small hole per pot doesn't seem like a huge amount of effort to avoid a lot of trouble later on...

[JustinFun]

Or to put it another way - what Heemis said.

Ninja'd by only a few seconds!

[merlinb]

In most of my early builds I snapped off the tabs, but eventually I started drilling the holes and never looked back.  If you use large enough knobs, you'll never see the hole...

+1. The key is there for a reason. Use it.

[puretube]

...
+1. The key is there for a reason. Use it.

+ another one...

[davent]

If a hole through the top is unsightly don't drill through. Hammond enclosures are thick enough you don't have to drill through to use the pot tab. You do have to file down the tab slightly but its such a soft metal takes no time at all.

I usually snap em off and use a inner-toothed lock washer to keep it tight and from spinning while tightening.

[amptramp]

I have put a panel under the front surface with holes drilled for the tabs so I don't have to drill the panel.  It turned out to be not such a good idea - there was only enough thread length on the pot for the nut and not enough for lockwashers or even the thin washers to protect the paint on the front surface.  Next time, drill the box and use knobs large enough to cover the tab holes.

[Frank_NH]

Taking the tabs off is a little bit of a pain for me, as I like to file down the ragged edge that remains after snapping it off.  Takes a minute of two for each pot.  I would be in favor of using the tabs, but drilling the small hole is an extra step (and you need to make sure you get it positioned just right), and if you need to rotate the pots to accommodate your internal wiring or board placement, then you're out of luck (or have to drill another hole).  In the end a simple lock washer should be enough to keep the pot from loosening and rotating under normal use.

[MrStab]

i usually cut the thing off with wire clippers and wait 1-2 seconds to hear it land somewhere on the other side of the room.
it's a fun ritual. until a piece shorts my motherboard or lands in my coffee or something.

in all seriousness, though, i've been increasingly tempted to actually use that tab, because it can be really tricky relying on the nut sometimes.

Dave: i've seen those locking washers a lot with toggle switches & commercial pedals - i know this is probably rudimentary machining knowledge, but the teeth give it some grip against the enclosure itself, right? just trying to picture how they work because it could be quite handy. don't think i've ever used them properly with switches, as they still turn easily (i don't use the tabbed washers they come with).

Edit: i think i'm picturing it now, i can see how those could be handy. probably doesn't keep things in place 100%, but better than the gymnastics i have to pull to stop pots spinning atm.

[acehobojoe]

Edit: i think i'm picturing it now, i can see how those could be handy. probably doesn't keep things in place 100%, but better than the gymnastics i have to pull to stop pots spinning atm.

You can't just tighten it really tight?

[duck_arse]

...
+1. The key is there for a reason. Use it.

+ another one...

me too. you'll see the anti-rotation pip on pots and switches (washers) and rotary switches and jacks. other parts have flats shaved outta their shafts not shaft - flange? spiggot? ferrule? for us REAL masochists to utilise.

I either use a sub-panel, thin as I can find, hack it all to buggery, no-one will ever see, mount pots and stuff on, poke through front panel, and you've got shafts that little less long so knobs sit low, and no sign of washers, nuts or paint damage on the panel IF you do it right. OR, use a bit of 3mm styrene (from a washing machine lid ...) or pespex to pad the parts, and mount nuts-out like you would normally.

I don't think I'd ever drill the extra hole through a panel without cover/hiding, but I use them everywhere I can.

[MrStab]

You can't just tighten it really tight?

it's what i have to do, but sometimes i find the actual process tricky. i've managed to damage a few pots (or at least stiffen their rotation) by tightening too much, but avoiding that is common sense i guess.