Board fixation

Started by soenke, February 20, 2014, 11:08:51 pm

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soenke

I just got my LIME-Board and was thinking about how to fix the board in my housing.
I think that any type of metal screw/sleeve combo wont work because there is not much space around the U-holes?

Maybe some kind of klick-in fixation?

soenke

@Olimex: what kind of fixation were you planning when you designed the U-holes on the sides?

Simon

Hi Soenke,
You may have noticed that Olimex sell a box for the thing. Actually it is a top an bottom half-shell. The two halves are screwed together from the bottom though pipes that run through the U-shapes.
The bottom-half shell has some supports pointing up where the PCB rests on. In honesty we have to say that there has been a little mishap, only 3 supports can be used, the fourth is shortened it is fighting with the pins of the Ethernet connector. The top shell has the same problem with the same Ethernet connector.
Then the Olimex box has front and rear laser-cut panels (that are yellow on the outside, hence the name LIME??) that enclose the connectors.

So if you would sum up the way Olimex "fixes" the board themselves; they box it in (limiting the X and Y freedom) and put it on a few studs (supporting the PCB and leaving space for the parts at the bottom). Next they limit the vertical movement by putting something over the connectors.

A simple way to fix the board without too much risk would be glue four plastic spacers in the U-holes using two part epoxy glue. I have spacers that are 0.15mm wider than the U-holes. So sanding of a little bit makes it fit.
Another way could be to glue small 3mm (or more) feet under the PCB, this protects all bottom parts and use the screwholes provided. Or glue two ears extending sideways from the board with holes.
Similarly using 3mm plastic, make 8x8mm blocks and glue the over the U-holes on the bottom side of the PCB, now you can drill holes in the U shape. Maybe this is the nicest.

I hope you see some light now, regards,
Simon

soenke

Hi Simon,

thanks for your reply and ideas!

I think that the basic idea on the fixation (screwless) is not bad for the one housing they build. But everybody else is screwed (like me).

I will try your glueing-variant and see if it works for me.

All in all these holes cost lot more than they spare. Simple round holes would have been way better.