I love this sled, it's made from 1/4"  luan plywood, has a hardwood runner, and a hardwood fence.  It's made my radial arm saw obsolete.  It's light but sturdy.  I've used is so much the runner is slightly worn.  I'm going to build another with a T-Track on the fence for a cutoff stop and a stick on measure.  

This dust filter is built out of an old squirrel cage blower.  It stacks 3 16" x 20" filters on each side.  The return air is through the floor joist to create a circular effect over my tablesaw.