I finally got around to redesigning the slider. It holds its spring a lot longer than the one in version 0.8. Although eventually it tends to come to loose. The only way I found to solve this is to put a small spring in the button. So the two flanges are pushed outwards. It's also just one part now instead of two. With that I had to slightly alter the upper and lower body. So these parts are not compatible anymore with version 0.8 parts. The first slide in and out could be tough but it should be fine after that.