Standoff nightmare.

[TheWinterSnow]

So recently revising my old designed I have decided to step away from the use of the plastic adhesive standoffs because they are hard to get into tight spaces with their large foot print.  I want to use a more traditional standoff/spacer method but have been having a heck of a time trying to find compatible parts that aren't an arm and a leg.  I am looking for something that looks more professional on the outside so I want to go with socketed hex head cap bolts, my local hardware store carries some but are limited in smaller lengths and I would like to package some in bulk with my other orders if everything works right.

Online I can't seem to find relatively cheap one stop place for the cap screws, female standoffs and traditional Phillips screws that are all the same thread size and a decent length.

For the most part I would like to use 2-56 thread size to minimize the screw head size as that size limits how close you can put traces to the mounting hole.

2-56, 4-40 or 6-32 is fine by me, but I prefer 2-56, metal components would be preferable and because I plan on using these for 1590BB builds with PCBs that have vertically oriented components, mostly 10mm resistors I need standoffs that are no larger that 1/4 inch in length and as such a socketed cap and screw that are both no longer than 1/8 in. in length from the head, although they could be up to 2.5mm and still be ok given the 1mm gap of the PCB and case.

I would like black on the hex socket caps, but it worst comes to worst, anything except nylon for the outside socket cap will do.  Nylon will also work for the standoff and PCB side screw.

Any help?

[dwmorrin]

Did you try McMaster-Carr?
http://www.mcmaster.com/#socket-head-cap-screws/=q1gstp
http://www.mcmaster.com/#standard-threaded-hex-standoffs/=q1gs7g

[TheWinterSnow]

See that is a sight I could not find through Google searches.  Mouser's parapemtric search when it comes to standoffs and fasteners doesn't work and still they don't have much and Grainger is expensive corrosive resistant steel alloy.  That place works.  Thanks, will bookmark.

[digi2t]

Stainless 3mm button head Allen is what I use. 12mm long, with Nylok nuts on the inside. The stand-off's are any small plastic tubing that I can find, I just cut off what I need with a thin Dremel cut-off wheel. Usually just thick enough to keep the trace side from contacting the enclosure (about 4 or 5mm thick).





I get them off EBay. I find them a bit more discreet than socket caps. Just my two bits.

[davent]

I JB Weld a couple 1/4" tall 4-40 aluminum standoffs to the enclosure.  First tack glue them in place using the PCB to hold them, then once that's set up, volcano the stand-offs with more of the JB to secure them real good.


Oozing volcano

[R.G.]

Online I can't seem to find relatively cheap one stop place for the cap screws, female standoffs and traditional Phillips screws that are all the same thread size and a decent length.

It is one of those quirks of the universe that "cheap", "one stop", and special parts are nearly always mutually exclusive.

[duck_arse]

I've been using 3mm hardware since I started working. I once found some pan head 3mm security hex screws on special in a local dick smith, but they turned out to be bent. nylok 3mm = hen's teeth around these parts.

not too far off topic: can anyone tell me what size thread the standoffs/coarse thread screws are in yr garden variety pc?

[TheWinterSnow]

The JB Weld thing I just though about and then immediately read it here.  Seems like an idea.  As for their ability, I was under the assumption that weren't specialty by any means, considering how often you see them in just about everything from automotive, electronics, musical instruments (guitars etc).

Standoff sizes in typical computers are 6-32 or 3.5mm-0.79

[TheWinterSnow]

quick question back at you Davent, or anyone for that matter, if you were producing small professional (commercial) runs of pedals would the JB weld method be acceptable and professional enough for commercial use or would you opt towards mounting the standoffs on both sides with screws?  I personally want to lean away from the JB weld but if more that enough people feel that it is still professional enough I will use it, even though I have now found the screws and standoffs needed and for cheap.

Also what is that isolation material on the inside of the board and how do you typically install it.  Looks like a liquid type material, you just taping off the sides and pouring/brushing enough in to get a good even coat or?  Looks like liquid electrical tape, correct me if I am wrong.

[davent]

I like the way Joe Gagan did it with his pedals. Countersunk screw through the top of the enclosure then a faceplate of some sort that would cover up the screw heads. Countersunk flathead screws could be made to blend in with the top as well, incorporate into the design.



If you're refering the black material in the one photo, it's rubberized rocker panel paint from the local Canadian Tire (auto/tire, housewares-camping-fishing-sporting goods-plumbing-electrical store).

dave

[TheWinterSnow]

That was why I was interested in the Socket Hex Caps, while they aren't discreet I personally feel that they have a look about them.  Some pedals and amps have used the same type of bolts for cosmetic and usually functional fasteners of some sort that look much better than a screw or generic hex bolt.

[joegagan]

davent, thanks. nice to have someone notice those details. i used to have a ' no glue or sticky feet' policy, hence the full-on screw in rubber feet and solid standoffs. i have since given in to glue for wah treads and other things, but i still like metal standoffs screwed through the enclosure.

we did the drilling prior to powder coating on the brontos,, the non-faceplate ones showed the screws, which wasn't bad because they were pre-installed before powder coating.
but you  are also correct, the faceplate was designed partly to hide the countersunk screwheads.

[joegagan]

dave

wow, that is a handsome and somewhat scary looking thing. LOVE it.

[davent]

Thank you Joe!