Quote Originally Posted by John S View Post
only dressmakers and the BBC dimension diameters as radii.
On the BBC they'd skip the interesting bit with dimensions!

I thought it was neater to dimension the radii, here's a version with mostly diameters:

Click image for larger version.  Name: Nema 23 Stepper mount2.jpg  Views: 2959  Size: 262.8 KB  ID: 4303

I can obviously make that hole bigger if required, up to about 50mm.