How to mount PCB in an enclosure?

[JoelTone]

What's the best way to mount a PCB in an enclosure, assuming the PCB doesn't have any special mounting holes, nor board-mounted pots or jacks? I have a few builds I'm doing right now - a Fuzz Face, an OCD, and a Klon. The FF is on perfboard, and the OCD & Klon are on PCB (GuitarPCB "ODC" & Grind Customs Chimaera). None of these boards have any special provisions for mounting, so I'm not sure what to do, short of using double-sided foam tape on the inside of the enclosure (which doesn't seem like a very good idea to me).

I know Small Bear has these standoffs, but I'm not quite sure how people use them. Stick them to the enclosure and let the PCB stand on them? What about the other side - just let the tallest components be the standoffs on that side? What prevents the PCB from rattling around in the enclosure - just keep the wires short enough that it can't move very far? These issues make me think these standoffs aren't a great option either, but maybe I don't understand how to use them.

Sorry if this has been asked a million times before. I did a search and all I found was this, which mostly ends up talking about the best ways to do if it you can design a PCB specifically for it - but that doesn't really answer my question.

[thelonious]

I usually find that once I get all my wires soldered to the board, it barely moves. The downside to using wire stiffness to keep the PCB in place is that over time, eventually, one of those wires is going to break because of the repetitive vibration/motion of the board. That might be 10 or 15 years from now, but eventually it will happen. When I build pedals for myself, that's no big deal, because I will continue to mod those pedals out the wazoo for the next 10 years, and break the wires myself when pulling the board out yet again to change a component.

When I build pedals for other people, though, I make sure I secure the PCB properly, usually with a few dots of of hot glue (often to the back of the pots). I like hot glue because it's relatively easy to remove if you really try, and it doesn't leave a residue like foam tape or epoxy. Hot glue sticks to the board with no problem, but with a metal surface like an enclosure or the back of a pot, you should first rough it up a little with sandpaper and then clean it with acetone or something.

[mremic01]

With no holes in the PCB, your options are a bit limited. Double sided 3M tape is pretty common, and hot glue will work. Just make sure anything in the enclosure that might short on the bottom of the PCB is insulated.

The best way to mount a PCB would be to have it screwed to standoffs, and have those standoffs screwed into the enclosure. This is best from a reliability standpoint. If you're a manufacturer and want to make pedals cheaply with a minimum of parts, having the pots, jacks, and switches mounted to the PCB so that they hold it in place might be the best way. But those big off-board components will tend to break at the solder joint over time. It's safer to have them connected with wires.

I use metal standoffs (http://www.futurlec.com/Hardware.shtml), but I use JB weld to attach the standoffs to the enclosure and have the PCB screwed into them. Plenty of guys use the tape, or those plastic standoffs that attach with tape, and they seem to be reliable, but I don't trust them. On the other hand, screwing the standoffs to the enclosure adds to the planning and drilling, so I've found the JB Weld is a happy medium. Even if all of the standoffs break away from where they're JB Welded, the wires will keep the PCB in place and the standoffs will keep it away from the bottom of the enclosure.

[GibsonGM]

On that note, I use a piece of foam (non conductive) under all my PCB's to make sure the solder side can't touch the enclosure, no matter what happens. It also pads the PCB, making everything fit nice and tight inside...and keeps batteries from moving around.  I think it's a piece of 'egg crate' mattress pad that I cut to make less fat.
   
I like the standoffs - I'll drill the box to attach them; the screws don't bother me.  I have a drill press, which makes putting holes in boxes/PCBs easy.

You can pre-drill standoff holes in a 'blank' PCB before you build - just hold it down on a piece of wood and carefully drill a very small pilot hole in it, followed by the size for whatever standoffs you have (something like 1/8").  I often do two diagonal corners, or in the middle of the L/R edges.

[smallbearelec]

The best way is to use an enclosure that has the studs machined into it, and a board that's made to fit.

http://www.smallbearelec.com/servlet/Detail?no=1378

It's more expensive than the other methods, but way more convenient and reliable. Doing it this way does mean that you have to design your layout around this "platform," but that's not necessarily bad. I am happy with some of the results:

https://www.smallbearelec.com/Projects/UrsaMinor/UrsaMinor.htm

Regards
SD