Wanhao i3 Plus extruder block designer's placeholder

**This is a placeholder object for 3D designers.** It was rough-modelled based on the critical dimensions of a real-world object. It has three intended uses:

1. **A virtual placeholder.** Import it into your CAD program and then build around it. This helps you position features like mounting holes, and allows you to visualise the design as a completed whole.
2. **A subtractive tool.** Use it to subtract a space from another shape, like making a knife sheath by using a model of a knife blade