I lost a couple height-setting spacers one day when the nut that holds them came loose and the bolt dropped out. Rather than pay for new ones, I slapped this together. They hold up for around 1 season of mowing (7 or 8 months) before they break down enough to require replacing. Adding a fender washer to the top (and even bottom) would drastically improve their lifespan.
See time-lapses of the things I print here: https://www.youtube.com/channel/UCQ9nW8XQAPWKGGKRd9LFQNQ
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