Noctua NM-APS3

This design is meant to approximate the Noctua backplate spacer for their NH-L9a cooler. It appeared to work all right for my installation, but your mileage may vary.

Reference Noctua's documentation for information about usage. Be sure not to overtighten and use with caution as without a true backplate you could warp or crack your motherboard.

Designed as parametric to allow for tweaking to get a perfect fit, but the default values provided are what worked for me.