Dave Bullard examines a 3-D printed “stick,” part of an excavator, during the first day of the 2017 CONEXPO-CON/AGG convention Tuesday, March 7, 2017, at the Las Vegas Convention Center. The massive construction vehicles garner immediate attention at CONEXPO-CON/AGG 2017 concluding today at the Las Vegas Convention Center, but it’s what’s tucked behind those monstrosities that could have the biggest impact.