housing 9 in the direction of the arrows each of the vacuum tubes 14 and 14 u2032 have their outlets at approximately or as near as possible to the center of the impeller 8 it has been shown through much experimentation that the introduction of the outlet end of the vacuum tubes near the center of the impeller is preferred as the dust and debris is vacuumed by the impeller into the vacuum housing 9 the dust and debris is discharged through exhaust port 10 and into the vacuum bag 11 the vacuum bag is detachably attached to the device so that it may be emptied as necessary another refinement to this device is illustrated in fig1 each circular saw blade has a lower blade guard 24 this lower blade guard 24 rotates as the blade moves through the material to be cut and must be pushed out of the way before the blade encages the working piece normally this is done by means of a lever on the side of the lower blade guard however since the outer side of the blade 4 is now fully contained within the saw blade chamber an alternate means of rotating the lower blade guard 24 is required this is accomplished using a lower blade guard rod 25 that is contained within the blade chamber the rod has a first end connected to the blade guard 24 as shown in drawing fig1 this lower blade guard rod 25 is also attached at a second.