Part of my design involves a membrane that has buttons. From experience getting the height right is a massive pain, you are really restricted by the height of the button and hope to find one that will work out exactly right. Especially when you consider the issues if you have your board under a LCD that has to be at the right height as well and the boards are linked by a connector.
So I'm really chuffed to have found these http://www.ebay.co.uk/itm/20-pcs-12x12x15mm-Momentary-Tactile-Tact-Push-Button-Switch-w-Yellow-Round-Cap/190836427887?_trksid=p2054897.c100204.m3164&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20140407115239%26meid%3D50aab482185647afbd4bfb841fec219e%26pid%3D100204%26rk%3D15%26rkt%3D30%26sd%3D290912809865
What is so nice is they have tight slot in the cap. So the button can slide around 2mm. In use you would mount your board and have the buttons poke through the panel. Then just push the button down flush with the panel. The 0.4 mm travel then leaves the button proud just the right height to sit under the membrane if you have an embossed button or you can push the button that little extra to make it flush.
If need be a drop of superglue on the shaft will fix the button permanently. Although its pretty tight and should not be needed.
- Button.JPG (24.16 KiB) Viewed 9035 times