I have a .680 and a .750. The .680 is about 20" long, and the .750 is about 15". Bothe are toolholder held. It's really nice to just engage the power feed and watch it go....The .680 is brandnew from sterling, all I had to do was screw in the air fitting in the end. It has the wood boring tip, the .750 doesn't and needs a pilot hole and also a hole all the way thru already to work well, but when I finally get the time to do the coring that is stacking up, I'll be using the .680 to go all the way through, and the .750 to do about 3/4 of the way to get a step effect. I do have to do a pilot hole, but the shape of the .680 drill is awesome at going thru solid wood, even ebony. I have set it up and then measured the setup and wrote it down so that redoing the setup takes less time (in a perfect world):grin:.
Kent, does your insert drill have an air tube to blow the chips out? It's not visible in the drawing. The one advantage to this type that I see is it would be nice to just change the insert rather than send the drill out for sharpening, or you could even change it for different types of wood.
Dave