I need a solid, flat disk that measures 6.5 inches in diameter with a thickness between 0.5 cm and 1 cm. A smooth 2-inch centre hole must let a cardboard tube slide in without snagging. Around the outer rim sits a circular groove, roughly 0.5–1 cm deep and wide, where thin kitchen string will wrap. Inside that groove, V-shaped ridges spaced 1 cm apart keep the string from slipping; the tops of the V’s are solid while the interior is hollow so the rope can settle firmly. To match the equipment I already run, the part should be printed in PLA with a matte surface. I would like the V-ridges reinforced by increasing wall thickness to about 0.4 cm rather than relying on heavier infill or specialty filaments. Feel free to adjust finer details if it improves strength or printability, but please keep the overall dimensions and purpose intact. Deliverables • Print-ready STL (and STEP if available) that follows the specs above • Recommended slicer settings for PLA—layer height, infill %, wall count, and any supports you find essential • Brief notes on how you ensured a smooth centre bore and durable V-ridges Acceptance criteria • Dimensional accuracy within ±0.2 mm on critical features • No visible layer seams or burrs inside the centre hole • Ridges withstand moderate rope tension without chipping or flexing If you can also provide an optional quote for printing and shipping the finished wheel, let me know; otherwise, the digital files and settings are all I need. the ridges should end in a very small point because I am using thin but durable kitchen string, but it will still lift a load