standoffs, tiny m3 long wood screws, or something for fixing pcb to wood breadboards?

Thread Starter

Hamlet

Joined Jun 10, 2015
264
I am stumped!

I build my projects on wood breadboards. Sometimes, I need to affix a pcb circuit
to the plywood/oak plank that forms the base of my project. I've used various
creative tricks in the past, from double sided foam tape, epoxy putty, saw kerfs
into the plywood, etc., but I am fed up with clunky solutions.

I would use some nice brass 30mm standoffs, either M2 or M3, but they don't
self tap very well into plywood, and the threads aren't deep enough, or quite
aggressive enough to bite into the plywood. I could use nails with a short
length of nylon tubing sleeve, but then I'd need a claw hammer to remove
the pcb from the plywood.

I often use drywall screws, 2" & 3" lengths, with a shorter nylon bushing made from
tubing, for holding large componets like transformers, but drywall screws are much
too large for pcb.

If I could find some long, yet tiny wood screws, I could use those with nylon
tubing to fasten down the pcb to the plywood.

What would you do?
 

bwilliams60

Joined Nov 18, 2012
1,247
My son is a cabinetmaker by trade and I can tell you from experience that #12 has hit the nail on the head (pardon the pun). Plywood is a layered softwood and does not hold screws well unless you get into the more exotic Russian plywoods and multilayered or laminated woods. Drilling through and using stand-offs would be your best bet.
 

GopherT

Joined Nov 23, 2012
8,012
I am stumped!

I build my projects on wood breadboards. Sometimes, I need to affix a pcb circuit
to the plywood/oak plank that forms the base of my project. I've used various
creative tricks in the past, from double sided foam tape, epoxy putty, saw kerfs
into the plywood, etc., but I am fed up with clunky solutions.

I would use some nice brass 30mm standoffs, either M2 or M3, but they don't
self tap very well into plywood, and the threads aren't deep enough, or quite
aggressive enough to bite into the plywood. I could use nails with a short
length of nylon tubing sleeve, but then I'd need a claw hammer to remove
the pcb from the plywood.

I often use drywall screws, 2" & 3" lengths, with a shorter nylon bushing made from
tubing, for holding large componets like transformers, but drywall screws are much
too large for pcb.

If I could find some long, yet tiny wood screws, I could use those with nylon
tubing to fasten down the pcb to the plywood.

What would you do?
They are called inserts. The m3 machine screw threads into the insert. The insert taps into wood nicely. Plastics are also molded over similar inserts in some products.

http://m.globalindustrial.com/m/p/fasteners/Threaded-Inserts/thread-inserts-for-wood/m8-125-insert-for-soft-wood-flanged-908125-13?infoParam.campaignId=T9F&gclid=CN-Fpqq97ckCFY0XHwod8ScBrw
 

Thread Starter

Hamlet

Joined Jun 10, 2015
264
So the idea is to drill four 3.5mm diameter holes into my 3/4 inch plywood,
spaced, uh, using identical pcb, marking the corners...

Then I use 1" M3 machine screws up thru the base, into my brass doubled
tapped hex standoffs, then use short M3 machine screws to mount the pcb
to the brass standoffs?

Sounds like I need a drill press.
 
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