Methods of securing PCB and perfboard circuits inside boxes?

[zenpeace69]

I did a search and didn't find anything.  I have seen some bad ways of doing this: velcro, crumpled cardboard, electrical taped boards floating.  I wanna do it right, though.  

What are some standard ways of securing a board into a box?  Pics or tutorials would be appreciated if anyone has any links.

Thanks!

[Torchy]

I use these


Base sticks to box floor and pcb sits on the "legs" ...

[lightningfingers]

Epoxy.

[Leandro]

What I would do is the following:

1. Take your PCB or perfboard and drill holes (if not already available) where you would screw the board to threaded spacers.
2. Screw a threaded spacer to each of these holes.
3. Determine how and where in your enclosure the board will fit.  Plan ahead for all jacks, battery, switch, etc.
4. Score/scratch the enclosure where the threaded spacers will be glued, and then lightly sand those spots.  Finally, clean with alcohol to remove impurities.
5. Mix some epoxy cement or similar strong adhesive, and apply it to the bottom of the threaded spacers and the marked spots on the enclosure (read the instructions on the cement to see how to apply it).
6. When ready, align the threaded spacers with the glued-up spots on the enclosure (try to get it right on the first go), en hold firmly in place with mild pressure.  Apply pressure on the spacers, not on the board.
7. When the cement has dried, unscrew and remove the board to continue working on it, if necessary.  You can also apply some extra cement now on the joints between the spacers and the enclosure, for extra stability.

Good luck!

[marrstians]

i usually use the pc board mounts from radshack... they're about two inches tall and have screws on both sides of the mount... you have to drill an extra hole in the face of your pedal for a small screw but they're tall enough to mount on top you your pots so you have plenty of room in your bb box... i think it looks a little more professional and it's real compact...

[zenpeace69]

These are some great ideas so far.  

How are you using the epoxy?  Do you put a gob there and just plop the board down?

Any other methods?

[zenpeace69]

I use these


Base sticks to box floor and pcb sits on the "legs" ...

Those look pretty simple and quick.  Where do you get them? They have a sticky side that sticks tothe box?  Then you just drill a hole in the board big enough to so that it makes it over the fat part of the pin?

[Leandro]

These are some great ideas so far.  

How are you using the epoxy?  Do you put a gob there and just plop the board down?

Any other methods?

Truth be told, I've only done the threaded spacer/epoxy thing once, using a local Argentine product which consists of a two-component epoxy mix which reputedly has the end-product strength of metal welds.  I didn't try to snap the spacers off, but a little lateral pressure didn't budge them a quarter of a millimeter.

Yes, I put a thin layer (about 0.5 mm) thick on the enclosure, and I dabbed about as much on the spacers.  Then, like I said, i aligned the board in the air, carefully lowered it in place, and applied mild pressure to the spacers (I used three of them; the fourth corner was crowded by a capacitor) until the mix settled and dried.

I got this technique from some web page, but I can't remember where.  It may have been the same web page where a former fish tank enthusiast showed how he recycled some fish tank parts to build an etching station (clever stuff)... but maybe not.

[Leandro]

I use these

[...]

Base sticks to box floor and pcb sits on the "legs" ...

Those look pretty simple and quick.  Where do you get them? They have a sticky side that sticks tothe box?  Then you just drill a hole in the board big enough to so that it makes it over the fat part of the pin?

Be careful if you use these sticky stand-offs in a box where you want to fix the board to the "roof" of the enclosure.  Depending on the quality of the adhesive, if you jiggle the box hard enough the stand-offs could give and fall.  They should work OK for "floor-gluing" the board, though.

I think they're more expensive than threaded spacers, however, but they're a lot easier to use.

[casey]

i use clear surgical tubing as spacers and regular screws with
lock nuts....does fine...

[Torchy]

[quote="zenpeace69
Those look pretty simple and quick.  Where do you get them? They have a sticky side that sticks tothe box?  Then you just drill a hole in the board big enough to so that it makes it over the fat part of the pin?[/quote]

I get them from RS Components, have used them in (almost) all my boxes. The sticky pad is _really_ sticky, and I havent had a problem with "roof" mounting. Use 'em exactly as you describe, zen  

[Leandro]

The sticky pad is _really_ sticky, and I havent had a problem with "roof" mounting.

I guess mine just plain sucked...   :lol:

[Fret Wire]

http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=64-2361

Double sided foam tape works if you mount the board to the back of the pot/pots. Allows you to use standard side-mounted input/output and dc jacks. Of course, if you're using a rotary switch, it won't work. I used the Radio Shack brand for reference, Mouser and Digikey carry the same thing, but better quality. The better brands (more sticky) hold real well.

There's the Boss/MXR method of mounting the board, trace side down against the bottom plate, with an insulating material to prevent shorts on the bottom lid. Boss uses clear plastic sheets, mxr used to wrap the board in foam. Both work well.

The bottom mount method is almost perfect, it just needs a mechanical means to fasten the board down (screws). With the trace side of the board sitting close to the bottom lid, you get the advantages of a ground plane. Plus, your board can be larger. It can run from the front of the box to the switch. On a 1590b, it comes out to approx. 5.5 square inches of board space. GGG's Big Muff board is 4.7 square inches, for example. TS-9's and BMP's could easily fit in the 1590b with this method. Just think of the original MXR pedals. They fit the Phase 90, Dyna Comp, Micro Flanger, Micro Chorus, etc. in the 1590b.

That's one of the things I've been working to solve, a mechanical bottom- mounting method. I tried epoxying threaded metal standoff's to the side of the box, but wasn't satisfied with the results. If you've ever seen an MXR Phase 100, you'll see that it has cast in standoff's to mount the board at the bottom. I'm still working on it.

[zenpeace69]

[quote="zenpeace69
Those look pretty simple and quick.  Where do you get them? They have a sticky side that sticks tothe box?  Then you just drill a hole in the board big enough to so that it makes it over the fat part of the pin?

I get them from RS Components, have used them in (almost) all my boxes. The sticky pad is _really_ sticky, and I havent had a problem with "roof" mounting. Use 'em exactly as you describe, zen  [/quote]

I just looked at RS Components, but I can't find those.  What is the part number?  What are they called?  

thanks

[Dan N]

I like to use a piece of sheet metal with a hole in it. The circuit board is screwed to the metal with small screws or standoffs, and the hole is for the footswitch to hold everything in place.

You can hopefully see what I mean in the photos:

http://users.rio.com/senorris/junk/std1ss.jpg

[Hal]

metal shaped like this:

Code Select Expand

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then rivet the bottom to the box and screw the top the the board....

nice and easy to remove, too.

[John Catto]

I've done this a bunch of different ways. If the circuit is neat and small then nothing beats PCB mounted pots, then the whole  thing can drop into the box as a unit secured by the pots. With Hammond type boxes with the slot supports (like the one in the photo in the post above)  inside I often make the board the exact width of the box and tack it in place with a hot glue gun, this works really well. I've used nuts and bolts with standoffs as well.

[soundcollage]

If you don't mind drilling extra holes in the enclosure, you can purchase skinny 1 1/4" bolts and nuts and then use an old bic pen case for spacers.
Just use snips to cut them to size. This is really cheap and does a suprisingly good job, plus the pieces of pen shaft are very forgiving of misaligned holes.

[RedHouse]

As of late I've been working up some templates for 1590-B and 1590-BB boxes.

Considering how Dunlop makes their Wah boards these days, it occurred to me that one could apply the same idea to Hammond boxes with a proper template, so I'm making some templates using Dunlop's method where the PCB uses RE'AN/Neutrik (Cliff) type jacks (and will include a 2.1mm power jack eventually) to support the board inside the box. Not to take any stress, just to support the board and eliminate stand-off's, glue, stickytape and other attachment stuff.

So far I have only done a 1590-BB template that has side jacks and one with end jacks, I will do more as time allows. They have the solder pads for the RE'AN jacks and outline where they go, and a outline where the stomp switch would go (current template is for a Carling because I don't have any of those Blue 3PDT switches, and I'm unemployed so likely won't get any in the near future)

Regardless of whether-or-not you're a fan of PCB mounted jacks, PCB mounted jacks can work quite well in effects pedals, specially if the pedals are pedal-board mounted, where the jacks just don't take any abuse because they're semi-permanently wired up and remain that way from day-to-day.

Wouldn't it be nice if projects could fit into a standard Hammond box without the usual one-off hacking we go through evey damn time we build something, and nearly everyone uses the standard Hammond boxes (eventually).

[gez]

If the circuit is neat and small then nothing beats PCB mounted pots, then the whole  thing can drop into the box as a unit secured by the pots

This is the method I use nowadays.  I use pretty thick wires to the board so even without slots the whole lot is pretty secure.  PCB mount pots make life sooooo much easier (less spaghetti).