Solidoodle SD4 Y Axis Belt Tensioners
Both of my factory belt tensioners broke within 3 months of owning my SD4, so I created these more substantial ones in Sketchup. They use either the original brass inserts scavenged from the factory parts (with a slight countersink for the shoulder on the stock parts) or EZ-Lok 240-M3-BR inserts after reaming the holes out to 4mm (5/32").
Inspired by http://www.thingiverse.com/thing:705297 and the factory part, but ended up doing a model from scratch.