Acknowledging that the switch to garbage trucks equipped with robotic arms has presented challenges, town officials have extended a grace period that allows residents to temporarily use their existing receptacles. Trucks will continue to accept garbage in any bin through the week beginning Monday. Peter Morin, Mayor Joseph C. Sullivan’s chief of staff, said around 80 to 85 percent of residents have switched to new bins that are compatible with automated pickup, while another 300 households have requested smaller, 35-gallon bins. The grace period was implemented to accommodate those who have not paid for a new barrel or did not receive one because of clerical errors. Trash will still be collected on the same days under the new system. Morin said automated pickup will save the town at least $750,000 over five years and is expected to increase recycling rates.