cnc flexible sanding drum head

thingiverse

Sanding uneven edges on wood leaves natural formations intact, simply smoothing them out. This technique is perfect for sanding large quantities; all that's required is creating a tool path. This particular method utilizes belt sander belts, which are cut up and require fabric backing. To assemble the belt, fold about 5mm of it back with the grit inside the fold, allowing it to slide into slots easily. You may need to sand the head slightly for a proper fit. Using a metal ruler aids in extracting the belt smoothly. The shaft used is derived from bits similar to the one depicted; I constructed this project some time ago and have since forgotten the exact dimensions, but you can create your own if you possess a lathe. The recess holds the nut for the shaft, and when the tool spins correctly, it tightens automatically. A hand-tight fit works flawlessly in most cases. To determine the diameter of the sandpaper, measure from half the width of one side to half the width on the opposite side (refer to the poorly drawn illustration). Set the bit as an endmill and initiate the toolpath away from the workpiece, progressing towards it in a radial motion. This results in one pass at full depth. Depending on material, sandpaper, and rpm, you may need to perform additional passes. When cutting the belt into strips, ensure the tool path circumvents one strip below the work piece. Although accuracy is not crucial due to the belt's flexibility, it's still essential for optimal results. Limiting the rpm to approximately 3000 ensures a steady sanding process; when bits fly out, they carry insufficient energy to cause damage. I tested up to 5000 with success but found it unnerving. This method works seamlessly with a dust extractor, provided a solid base is used instead of brushes. The accompanying stp file has been uploaded for modification purposes. Feel free to adjust the design according to your needs.