Stainless steel choker, made from hex nuts, small bow shackles and a hex nut cross.
https://www.sailrite.com/How-to-Work-Binding-Around-Corners-or-Curves-Video How to Work Binding Around Corners or Curves Video is a great demonstration video for installing binding around a corner when using a standard feed binder attachment. Installing binding around a corner is not as difficult as it seems. For gentle curves, turn the fabric slowly while feeding into the binder slot. For 90 degree turns, cut the binding at the corner and sew down with one side overlapping the other.