This item is for use with the #GridFinity system by Zach Freedman:
https://www.youtube.com/watch?v=ra_9zU-mnl8
These bit holders are parametric, a group of 9 bits will be generated for each module deep and wide selected. Values bitSize controls the bit shank (6.25mm or 4mm usually) and slopSize controls the extra 'space' around the holes. I find a value of 0.2 works well here.
If you lower the extrusion of the holes from 10 to 5 they work well for holding MK8 compatible hot end nozzels as well.
You can use the .f3d archive to edit the parameters as you choose. You can also go into the sketch and adjust the spacing directly, or edit the extrusion and choose if you would like the strain relief lines or not. I've uploaded some pictures of my customized ones as an example.
Source file included.