The dust extraction systems of available orbital sanders do not perform well when the sanders are used on edges or pieces that do not contact the entire sander base. In an effort to improve the situation a number of experimental bases have been fitted to a sander, with holes in a variety of patterns. Many patterns give good performance, and particularly good dust extraction can be obtained through 10 carefully placed holes, only two more than the number in a standard base. Holes with a diameter of 5 mm give a better performance than 10 mm dia. holes. The effect of varying the extraction flow rate has also been investigated and it is found that the efficiency of dust collection varies approximately linearly with flow rate until a maximum of about 90% is reached, after which little improvement results.