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DIY Stompboxes => Building your own stompbox => Topic started by: newfish on January 03, 2008, 05:57:54 AM

Title: Board Mounting
Post by: newfish on January 03, 2008, 05:57:54 AM
Hi All,

Having successfully built a few effects now, I realise the only thing lacking is a proper way of mounting the circuit board inside the box.

An obvious solution would be to use a standoff / nut and bolt arrangement.

I was wondering if there's a more elegant (i.e. less visible from the outside) way of holding your boards securely in place...

Any takers?

 ???
Title: Re: Board Mounting
Post by: rikkards on January 03, 2008, 07:48:52 AM
Hi All,

Having successfully built a few effects now, I realise the only thing lacking is a proper way of mounting the circuit board inside the box.

An obvious solution would be to use a standoff / nut and bolt arrangement.

I was wondering if there's a more elegant (i.e. less visible from the outside) way of holding your boards securely in place...

Any takers?

 ???

The first thing I did was go to Home Depot and buy some of that industrial glue and buy some small screws and twice the amount of nuts. I was going to glue a set of screws into the inside of the case, then put one nut on to keep the board from touching the case, and then sandwich the board between that nut and another. Repeat for another screw or two.  Total cost was less than 10 bucks. Then I realized what I was trying to mimic which was essentially the plastic standoffs that motherboards are mounted in computer cases with.  Went to the local Active-Tech and spent a couple bucks for about a hundred of the standoffs.

What I know do is I drill a couple holes in the PCB, cut off the bottom of the standoff which usually gets wedged in a slot when mounting a motherboard and then glue that down. Here is an example: http://www.directron.com/standoff.html

Hope that helps!
Title: Re: Board Mounting
Post by: DougH on January 03, 2008, 08:14:09 AM
I used to glue the bottom of the standoffs to the inside of the box with JB Weld. But I have found that inevitably it will come loose, so I don't do that anymore. I just drill and countersink holes in the box and use flat head screws to mount the standoffs to the box. I print the graphics for the top of the box on a vinyl sticker, which hides the screw heads. Sometimes you can see a slight indentation so I'm going to try dabbing a little JB Weld, Bondo, or putty into the holes and sanding them flush with the box. It sounds like a lot of work but it's not. It's only two holes.

Some people use pcb-mounted pots and just use the pots to support the board. I use perf, not pcb, so that's not a good solid mechanical connection in my case. Also, I don't like depending on a solder joint to provide mechanical support. I'm kind of anal about that even though in this particular case it's probably okay, as 9v pedal components on a small pcb tend to be pretty light. But mounting the board on screwed in standoffs has been the best mechanical solution for me. Everything else I've tried (glued standoffs, velcro, etc) has failed. There are all kinds of ways of hiding screw heads. Just need to get your creative artistic juices flowing. :icon_wink:
Title: Re: Board Mounting
Post by: newfish on January 03, 2008, 08:32:57 AM
Thanks Guys.

Will go down the PC board route - since I have some (and some strong glue) to hand.

I'm also not keen on using components as mounting points, for the same reason.

Cheers.

Next up, a big fat Fuzz Face...

Ian.
Title: Re: Board Mounting
Post by: darron on January 03, 2008, 09:11:47 AM
i don't know why people don't just do this?
(http://members.optushome.com.au/bluespherecreations/forum/ge-fuzz3.jpg)

mount the board directly on the switch. make the holes in the pcb as tight as you can difficultly get the switch in there. it's strong enough just like that. once you solder it on it's VERY secure and reliable.

here's an example from a pcb layout i finished last night (a bit messy! haha):
(http://members.optushome.com.au/bluespherecreations/forum/tremolo.gif)


the red represents the battery, the audio jacks (sits under the pcb if you are looking at the guts from the bottom) and the switch. i leave the gap between the switch and the footprint of the components for the audio jacks to comfortably sit in. then i heatshrink the base of the switch since i fear the audio socket shorting on it to groung.
Title: Re: Board Mounting
Post by: DougH on January 03, 2008, 09:44:34 AM
That's not a bad idea - if you use pcb, have room to run it over the jacks, and have no qualms about mounting it upside down like that. Not a bad idea at all...
Title: Re: Board Mounting
Post by: newfish on January 03, 2008, 09:58:11 AM
Cool.

Never thought of that.

Since I'm still building on strip board, I'll have to wait until I start etching boards, but it's certainly an idea for the future.

*unless* I could be a little smarter with a dremel and some breaks in the board.

(...thinks...)
Title: Re: Board Mounting
Post by: railhead on January 03, 2008, 10:31:40 AM
The PCB on the switch has always intrigued me, but it's such a waste of copper clad IMHO. :(
Title: Re: Board Mounting
Post by: R.G. on January 03, 2008, 12:14:47 PM
Yep, you don't want to waste that $0.05 per square inch copper clad. Much better to waste 45 minutes of time by cutting wires to fit, stripping the ends, tinning, then soldering each end one at a time.

 :icon_biggrin:
Title: Re: Board Mounting
Post by: miqbal on January 03, 2008, 01:43:57 PM
Sometimes they don't need any mounting at all. Just cover the the bottom enclosure (the same side with the pcb trace) with paper/glued paper, and let the wires hold the pcb, the pcb won't moved. It works for me for small to medium size pcb.
Title: Re: Board Mounting
Post by: mnordbye on January 03, 2008, 04:14:51 PM
Two things that i've thought of doing, but i'm out of enclosures at the moment (Thanks to Banzai! Anyone had any troubles with them the last month by the way??).

First, to mount the PCB or stripboard directly on the back of the pots(put some tape or something in between of course) would save space, and make it rigid too.

Number two, i've got the idea of using magnets to hold batteries instead of battery holders. Great idea,whoever came up with it! I was thinking of doing this with boards too, then you easily take them out again for modding. For example, glue a magnet on the bottom of the enclosure and one on the board. How does that sound?

Magnus N
Title: Re: Board Mounting
Post by: rikkards on January 03, 2008, 05:44:28 PM
I just built a Thor and there was no room in a 1590BB. Well there would have been if I had put the stompswitch about 2 mm to either side but I wanted it in the middle. Anyways, It fits nicely between the pots and the cover and doesn't move as the output jack is right next to it.
Two things that i've thought of doing, but i'm out of enclosures at the moment (Thanks to Banzai! Anyone had any troubles with them the last month by the way??).

First, to mount the PCB or stripboard directly on the back of the pots(put some tape or something in between of course) would save space, and make it rigid too.

Number two, i've got the idea of using magnets to hold batteries instead of battery holders. Great idea,whoever came up with it! I was thinking of doing this with boards too, then you easily take them out again for modding. For example, glue a magnet on the bottom of the enclosure and one on the board. How does that sound?

Magnus N
Title: Re: Board Mounting
Post by: railhead on January 07, 2008, 07:24:45 AM
Yep, you don't want to waste that $0.05 per square inch copper clad. Much better to waste 45 minutes of time by cutting wires to fit, stripping the ends, tinning, then soldering each end one at a time.

 :icon_biggrin:

Well, in the above pic, I could use the 2 side sections (on either side of the switch) to fit my fuzz circuit, so I'd be able to get at least 3 boards out of that one piece -- that's all I was getting at.
Title: Re: Board Mounting
Post by: bipedal on January 08, 2008, 10:15:03 AM
I stumbled upon 3M's Dual Lock tape for board mounting -- it's sort of like extra heavy-duty velcro.  One piece stuck to the inside of the enclosure, a few smaller pieces placed on bottom (solder-side) of the circuit board near the edges, then snap 'em together in place.

The backing tape adheres well to the inside of a metal enclosure and to PCB boards, it makes an audible "click" when two pieces are brought together, and it holds the board in place well, yet it's still quite easy to remove or reposition a board if needed.

Plus, the adhesive tape has a touch of squishy "springiness" to it -- a little built-in shock absorption for the board for those extra-emphatic stomps. :D

- Jay
Title: Re: Board Mounting
Post by: GibsonGM on January 08, 2008, 10:20:05 AM
I used to spend a lot of time JB welding standoffs in enclosures, etc etc....now, I just use some eggcrate (open cell, non conductive) foam once my enclosure is packed....I cut pieces to slide into the open spaces to keep the board from moving around, and make sure the bottom of the enclosure has a few layers of paper glued to it.  I also put a very thin slice of foam over the solder connections on the bottom of the board for added insurance. 
Haven't had any trouble at all with this method.
Title: Re: Board Mounting
Post by: bean on January 08, 2008, 03:46:24 PM
3M dual sided foam tape is and easy solution. Mount the PCB directly to the pots. Comes off easy, but stays secure under normal pressure.