Standoffs - Board Mounting

[KazooMan]

When I finished my version of Deadastronaut's Abductor Delay, I realized that there was no open space on the board to drill holes for a pair of standoffs and I had neglected to realize this and allow some extra size on the board when I made it.  I don't like having the board just floating in space or taped down to some foam or whatever.  I finally decided on using some nylon spacers to hold the board in place.  This may well be old hat to many, but I hadn't seen it so I thought I would share.

I purchased a pair of 3/8" diameter nylon "bushings" or "spacers" or whatever they call them at the local Big Box store.  I also got some nylon screws, but this is not necessary.  Both are cheap.  I cut what are basically the plastic tubes to the length I needed and used a Dremel tool with an abrasive bit to cut a notch in the side at the desired height.  This was done to make a snug fit on the PCB board.  I ran the screws through and added nuts, placed them on opposite sides of the boards, and then set the whole thing down into waiting pools of epoxy on the inside of the enclosure.  When the epoxy began to set, I removed the screws to be certain they would not stick, leaving the nuts in the epoxy.  Let set overnight and then the board can be returned.  This holds it as well as any commercial standoff I have used.  The height of the board off the enclosure can be varied as needed to allow for wiring, LEDs, etc. 





PS:  Kudos to anyone who recognized the Small Clone Chorus PCB used for the pics!

[haveyouseenhim]

Way to be resourceful     I'll be using this in the future.

[davent]

Cool idea, stash that one away for a future problem solver!

[duck_arse]

a nice idea.

do you cut small notches in the pcb where the screw passes? this could be used as a positive stop on the pcb once the screw was inserted.

[Kipper4]

Sweet idea man thanks for sharing
Rich

[Jdansti]

Great idea also because sometimes boards don't have enough room on them to drill holes. Thanks for sharing.

[KazooMan]

a nice idea.

do you cut small notches in the pcb where the screw passes? this could be used as a positive stop on the pcb once the screw was inserted.

No, I didn't think of that.  It's a great addition to the concept.  I just relied on having the slot be a good tight fit.  A notch in the board would allow for an easier sizing of the slot.  I notice that I said I used an abrasive bit to cut the slot in the spacer  Actually, I used one of their abrasive disks mounted on a mandrel.  You could just as well use a hacksaw blade.

The nice thing about using the nylon bolts is that you can easily cut them to the desired length.  You want them to fit into the nuts without bottoming out before the assembly is tight.  Run a spare nut onto the bolt and then cut it with a hacksaw.  Taking the nut back off cleans up the threads.  If you are using a metal bolt you should cut the nylon spacer carefully to a length that is just a bit shorter than the shaft of the bolt.

These nylon spacers come long enough that you could easily stack two boards on top of each other, or mount a board above pots.

[duck_arse]

I only mentioned the notch because I couldn't work out what was holding the board in place. have you thought of tapping the spacer? that would do away w/ the bottom nut, and you wouldn't need to tailor the screw length, it would only need to be long enuff to pass the pcb.

[Jdansti]

It appears that the notch only cuts through enough of the wall of the spacer so that the screw still passes through. The board is probably held in place by placing the nuts in the right position to give it a little squeeze. It would also help if the notches were thin enough so that you'd have to force the board into them.

[deadastronaut]

nifty..

[KazooMan]

It appears that the notch only cuts through enough of the wall of the spacer so that the screw still passes through. The board is probably held in place by placing the nuts in the right position to give it a little squeeze. It would also help if the notches were thin enough so that you'd have to force the board into them.

Yep, that's how they were cut.  You have to push the spacer on the board.  It stays in place all by itself.  The notch is just deep enough so that the screw can pass through the hole, missing the board.  The suggestion to make the notch deeper so that the screw shaft would engage a corresponding notch in the board should work also.

[Philippe]

velcro also works...for some, it has replaced the use of standoffs.

[merlinb]

Great idea!  What are these spacers normally intended for?

[KazooMan]

Great idea!  What are these spacers normally intended for?

I have no idea.  I got them at Lowe's.  They have cabinets of specialty nuts and bolts and some oddball items like the nylon spacers and screws. Any thick walled plastic tube should work fine.  You could easily use a chunk of plastic and drill your own hole. 

[davent]

I've bought them from Digikey, just nylon standoffs, threaded or unthreaded.

http://www.digikey.ca/product-search/en?pv70=6&FV=fff40020%2Cfff803ee&mnonly=0&newproducts=0&ColumnSort=0&page=1&stock=1&quantity=0&ptm=0&fid=0&pageSize=500