About this 3D model

This is the latest generation of what is called quadArc in quadrap-3d-printer community https://plus.google.com/u/0/communities/103539262895202172380This rigid cross carriage is the product of my colleague Cedric Wiemann and myself working on https://photos.google.com/share/AF1QipOfAGC4wZJFZOK9-qxYgBf-Dym2JKDo_dxq2vwq7NF2uGhHv1kmM-kCZipkA5LuzQ?key=aVAtcThncU5idmFndjBzNHowYlplWldSTmNwaFVnThe precision this cross carriage gives demonstrated in this video: https://www.youtube.com/watch?v=edhJU5v7UeQ and the final print photos here: https://goo.gl/photos/MUVBb8mPm5vLedm98