Core One L roof rack HSW lock nut

HSW insert / attachment to help lock a HSW to the Core One L roof rack . Insert expands with an M3 screw to ensure a good, non-permanent, grip. Printing Material : PC recommended for structural strength and heat resistance. ASA, PETG should be fine as well. Nozzle : 0.4mm Layer height : 0.2mm structural Infill : 15% gyroid or whatever Perimeters : 3 Solid layers : 5 top, 4 bottom Brim : not needed Supports : not needed Bill of materials Printed parts: COL-roof-rack--accessory--HSW-attachment-insert-locker.stl contains a single piece, copy as needed. Non-printed parts: 1x M3x16mm socket screws per piece. Shorter M3 might be enough depending on the tolerances of the parts. Assembly Insert the lock nut into HSW with the attachment. Place HSW on the roof rack, lining up the insert and, well... insert it into the roof rack. Drive in the M3 until the legs of the nut have expanded to keep the HSW in place securely. When all is done, I'd love to see you roof rack. Consider leaving a make and sharing your roof rack adventures. A like is appreciated if you got some use out of this model. Changelog 2026-04-17: initial version