Rotary switch - how to mount?

[schrectacular]

I'm building a pedal that uses a pcb-mount Alpha 3p4t rotary switch. Silly question - how do I mount these?

They have a little plastic nubbin that sticks up above the bottom of the threads and come with a locking washer. I think I leave the nubbin and put the locking washer and nut on the face of the box. Or do I cut the nubbin off like I would on the little spacer that comes on a potentiometer? If I don't, it feels like it's pulling the rotary switch off-center. Or does this not matter since it's soldered to the pcb?

[Kevin Mitchell]

If you don't use the locking washers on the inside then you'd be relying on the enclosure itself to keep the throw peg in place - you know, that washer that sinks into the switch to select how many throws it has access to.

Slice or keep the nub. It all depends on the required spacing height of the other controls. You may want to solder any right angle pots when you go to mount the circuit in the box. Then you can hash out what is needed such as raise the pots a bit and/or snip the nub to even out the clearance.

You may be familiar with the Meatball clone project. Some folks had complaints that they weren't able to solder the pots & rotary switches flush since the switches have more height. This could have been remedied by soldering the pot leads a little higher. Well, also adding a nut to the underside of the pot to make up the clearance.

[Rob Strand]

You can see the bits here and the washer,


and you can see the holes where the limit washer pokes in here,

[schrectacular]

Thanks all. Yeah that's a similar rotary switch, but not the 40mm version sticking out to the moon. If I don't cut the nub off, then the locking washer on the inside would do nothing... I plan on mounting the switches first, then soldering the board. I think it's easier that way.

[duck_arse]

the nub is for anti-rotate of the switch body on the panel, it has nothing to do with the stop-select washer. stop-washer goes in, nub passes thru a hole drilled for it, ITL washer and nut go on and tighten to the panel. if -- IF -- you don't use the nub, cut it flush to the level of the stop-washer fitted.

[anotherjim]

Those lock washers are smooth on one face and can work on top under the nut without messing the enclosure surface too much -  I usually do this. There's no dress washer supplied anyway.