Kryptonite New York Bike Lock Silicone Donuts

thingiverse

This is a printable mold for creating silicone donuts to prevent a Kryptonite New York from rattling around while riding, making excessive noise. The donuts are designed to fit the 16mm diameter shackle of a lock model but may also work on other sizes. I created this method by experimenting with designing soft robots and I'd love to share more about it. If you're interested in building your own soft robots or combining 3D printing and casting, check out my book here. These donuts were cast using Smooth-On EcoFlex 00-50 and have been holding strong for a week, but they will likely last longer if made with harder, tougher silicone. This project requires the following materials: * 4 M5 20mm Socket-Head Cap Screws * 4 M5 Nuts * EcoFlex 00-50 (at least 40g) * Mann Ease-Release * Vacuum Chamber and Pump * Nitrile Gloves * Digital Scale * 2 Mixing Cups * 2 Tongue Depressors * 3D Printer and PLA Filament To make your own donuts: Print out the parts in PLA, setting wall thickness to over 1mm and infill at least 20%. Clean up the print and give it a light spray with Mann Ease-Release. Assemble the mold halves using M5 nuts and bolts, clamping them together until no light leaks through. Mix together your silicone (about 20g for filling the mold). Measure everything out with a digital scale, wear gloves, and use new cups and tongue depressors for each batch. Degas your silicone and pour it into the mold, slowly pouring in a thin stream until the sprue becomes occluded. Once cured (~4 hours at STP), remove the bolts and pry the mold apart. Use nail scissors to snip off the sprue/vent material and any flashing. Once you've cast two donuts, slip them over the ends of your U-Lock, compressing them between the plastic cover/aluminum mount and the lock body.