This is a customizable scabbard for a combat commander knife I received from Budk.com as part of one of their box deals. Its a four piece assembly that is meant to be held together using cord of your choice. It can be paracord, tripwire, leather lace or any similar cordage. Make sure you print the sheath twice, as both halves are mirror images of each other. You will need to M3 x 5mm screws to attach the clip to the base though.

For my print, I used bright green PLA for visability and thin, black cord to tie it all together.

The fit is tight enough that the dagger won't fall out and the belt clip can be reversed (upside down) so it can be worn on a should strap upside down. The cord makes sure the fit stays tight, yet flexible without risk of breaking the materials.

I used PLA for my print, but I don't see a reason ABS couldn't be used.