Small XY servo movement

thingiverse

If a small movement (10x10mm) with big force and high speed is required the current design is the ideal solution. By using an eccentric and bearing the rotation of the servo is converted into linear movement. Similar movement of the milling head is used in Shaper tool - https://shapertools.com/ A video showing how the design is working could be found on: https://www.youtube.com/watch?v=ErpPezxVQ-A Converting the rotation angle of the servos into Cartesian coordinate system requires some trigonometry calculations. Custom Section Trigonometric relations The calculations are absolutely the same as in double SCARA robot or sometimes called "five bar robot". One really good example which also includes C++ library is listed below: http://robdobson.com/2015/05/scara-arm-calculations/ The C code (uploaded here as ZIP file) could be found on:https://developer.mbed.org/users/Bobty/code/SCARA_Arms/ In any case uploaded the image with the formulas below from robdobson.com. You can see that the eccentricity works as the distance "ShoulderToElbow" . Another good source of trigonometry explanation (which is not directly applicable for SmallXY because elbow = shoulder) is: http://forum.conceptforge.org/viewtopic.php?f=7&t=184 What could be used for Wally RepRap could be used in the SmallXY calculations. Another examples of double SCARA: http://www.3ders.org/articles/20130913-reprap-wally-beta-kit-makes-first-moves.html http://www.mecademic.com/DexTAR.html