Wanted to add wheels to my IKEA BROR system (65x55x190cm; model 294.717.59 in my case; uses BROR posts model 103.332.87), so made this mount. No modifications needed in BROR system itself.

Printed in MK3S+ from PETG, 0.3mm layer, 4 walls, 30% infill (you can use your own parameters).

Wheels have ~ 37x46.5mm base plate with 33.8mm and 23.8mm spacing between holes center points.

Wheels mounted using four M5x10mm hex bolts and self locking four M5 nuts for each wheel (bolt on top, nut on bottom - this orientation because top area needs to be flat for bror leg).

Fusion 360 and step source files attached.

Edit:

Stronger (v2) version added. Printed (on X1C) with PETG using “0.28mm Extra Draft” mode and 8 walls. M5x12mm/14mm.