<br> ## Single sliding axis. 3/2/21 Wood block sliding on flat stock parts. Spring provides varying load to oppose motor string tension and prevent backlash. Cable is nylon - steel will be stiffer. Magnets provide y-preload. Downward component of string and spring force provide z-preload. <img src="slider_axis.jpg" width="50%"/> <img src="slider_magnets.jpg" width="50%"/> This approach did not give smooth enough operation, especially when another axis was added. This is not a practical way to get a simple meachanism. ## Jake's suggestion 3/17/21 for a simple rotor.  ### 3/23/21 prototypes. First prototype abandoned for instability wrt torque. Jake's first sketch makes more sense. <img src="spindle-v0.jpg" width="50%"/> Second prototype runs with an o-ring. O-ring is one size smaller (12mm ID vs 14mm) than groove. Run with Clank at 7000 RPM. It spits the bit out the left side.Next steps: * Increase stiffness by: * adding support so that the frame is stiffer. * constraining oring better, or using two. * Using polyurethane driver. * Move rollers apart to increase depth of potential well. * Run using another ESC, so that I can run at any speed, and so Clank can be reserved for Clankier things. Once I demonstrate that it can cut traces, board outlines, and do table levelling, then we can explore motor choices. * See if there is any reason to work with 623 (3x?x10) bearings for size reduction. <img src="spindle-v1.jpg" width="50%"/> ###March 25 Specs for NEMA11 motor from CBA: https://www.pololu.com/file/0J687/SY28STH45-0674A.pdf * 6.8 OHMs per phase. * Should work at a few K steps per second (spec sheet not clear on this).