On Wed, 9 Jun 2004 15:28:17 +0100, "Dave Marsh"
vaguely proposed a theory
.......and in reply I say!:
remove ns from my header address to reply via email

Ideas:

(1) If you placed a panel behind the front panel, stuck to the front
panel and made of something eminently glueable, you get a huge area of
contact on the front panel aluminium, and an easily-glued surface
behind it. On such a large area, even contact cement would hold.

I am thinking of some of the "super cardboard" fibreboards etc, gasket
material etc.

OR

(2) If you can place the circuit board closer than 1/4" to the panel
that holds it (say 1/8") then you can adhere a standoff panel to the
front panel with plenty of area, and bolt the cctbd to the backing
panel.

(3) Place spacers _behind_ the cctbd, so that there is no pressure on
the panel, except that carried by the back wall of the enclosure or
columns from the bottom.

(4) Re-design the project box as many would. Countersink the front
"working" panel by pressure, to allow csunk screws. Place a
prettypanel in front of that, label and all, held by the edges of the
box (if it's one of those slotted things), or again simply held on by
contact.

Hi,

I need to space off a PCB by 0.25" behind a small (4" x 1" x 0.06" thick)
anodized aluminum front panel for an electronics project. The PCB contains
the push buttons that protrude through holes in the front panel.

The PCB has M3 holes drilled for fastening purposes but I can't put holes in
the front panel for appearance sake. I need to fasten the PCB strongly
enough so there is no danger of it coming loose when the user presses one of
the buttons.

My idea so far is to glue 4 metal hex spacers to the back of the aluminum
panel. I can then bolt the PCB to that. Alternaitevely the same kind of idea
but glue the flat heads of 4 countersunk M3 screws to the panel instead (I'm
thinking the contact are of a screwhead will be greater than that of a hex
spacer with its central thread hole).

The hex spacers are made of nickel-plated brass. The screws could be zinc
plated or stainless steel.

So far I've tried an epoxy ("plastic steel" by Draper) with the hex spacers.
Initially it seemed ok, but with a small amount of leverage the spacers came
away.

Could someone please suggest whether I would get better adhesion on the
anodized aluminum with the zinc screws, stainless steel screws or the
nickel-plated hex spacers? What epoxies would you recommend? I've also been
advised that curing the epoxy will improve the adhesion - does this make a
big difference?

Many thanks,

Dave



************************************************** *****

Sometimes in a workplace you find snot on the wall of
the toilet cubicles. You feel "What sort of twisted
child would do this?"....the internet seems full of
them. It's very sad