This thing was made with Tinkercad and is a derivative. I widened the sensor holes to 16.5mm, doubled the stand-off legs and mounted both sensor holders 90 degree, working to keep it parametric (as much as possible in Tinkercad). Works like a champ with the HC-SR04 Ultrasonic Module Distance found on ebay which is easily used with Arduino robots. 3d Print, mount on servo, measure distances. Whee!