Protecting the button
For a few years the standard bluetooth model of the vario has incorporated a simple push button for turning the vario on and off (see here for button instructions). This is much harder to get right than most pilots realize. A vario button that works well should:
- Be easy to turn on and off, including in flight while wearing thick gloves.
- Work with the case.
- Be a pretty common part that is available for the life of the vario.
- Be cheap.
- Not turn the vario on accidentally.
Unfortunately there is no perfect combination and there are trade offs. For earlier models of the vario there was a slide switch which broke if it had too much force. The most common issue with the recent Bluetooth models is that the button turns on accidentally when the vario is in a pocket or being carried. There is an easy way to protect it.
A small cheap washer glued around the button is pretty effective. Search aliexpress or your favorite online parts supplier for ‘M5 countersunk washer’ to find a washer like the ones shown below. The aluminium ones shown below are available in many different colors.
Use a reliable two part epoxy glue. Make sure to remove the board from the case prior to gluing so you do not mess things up (carefully, so you do not damage the button or USB connector).