The diamond core bits on ebay are real cheap from china and some work well. I used them to punch these beads out and drilled the holes by eye, some you can tell, some not. The material is stuff I collected in Hachita. I then used pins in small pin vises to hold the bead against a vertical 6" diamond flat from Lopackis rotating at about 600 rpm to rough them in and homemade sanding wheels of the flap design to sand down to level where I could finish with diamond powders. See his bead tutorial at lopacki.com for information on how the bead works. The bottom pix is before polish at about 200 grit sanding level....b
Friday, November 28, 2014
Thursday, April 3, 2014
This works very well, providing a few things are considered....the shaft, when wet, will cause the tire to lose its grip, and stop spinning, so the slurry/water amount is critical, keep it on the dry side. One shaft can run more than one tire. Use shaftstops and washers to keep separate, and also plastic separators can be made to ride between tires as splash guards and to reduce contamination of grits. The speed of the shaft should not exceed 100 rpm, and you have to get that right by adjusting motor speed and/or pulley size. One of my better innovations is attaching motors to cinder blocks so they can be hefty enough to pull and they can also be clamped easily, but can be moved around as well. This tumbler was a lot easier because of that kind of set up.