I bought the X900 tricopter frame from Hobbyking, and unfortunately crashed it fairly early on breaking one of the motor mounts. At this stage spare parts are not available, and while commercially produced CNC'd parts are available they are heavy. These mounts have been designed for the X900 using 3mm aluminium bar stock from the local hardware store. The design minimises the size of the motor mount and is actually considerably lighter than the glass fibre original mounts. The design files were generated in CamBam and can be resized for larger motor sizes if required. The geode (.nc) files have been designed around a 3mm end mill for all cuts.The design was simply marked up in cam bam. Its not perfectly symmetrical, it is perfectly functional. The actual mounts were manufactured on a Seig X2 mini mill converted to CNC using a cncfusion kit. A 3mm end mill was used for all drills, profiles and rebates so no tool changes necessary. The base stock was a length of 3*50mm aluminium bar stock from Bunnings costing approximately AU$7, and can be purchased significantly cheaper. The inner section of the motor mount has been routed down to 2mm to reduce the weight of the mount while keeping the outer rim @ 3mm for strength.