Champaign Woodworkers Club has a Leigh DR4 Dovetail Jig with additional attachments for Box Joints and Mortise and Tenons.
The Leigh DR4 Dovetail Jig allows for adjustable dovetail designs that other dovetail jigs do not allow.
Half Blind Dovetails
The WoodGrater has long list of videos on the Leigh D4R Pro Jig
Here is the video Jim Anderson discussed on the safety guards for the lahes.
And while we are on the topic of safety at the lathe, here is a video on how to address cracks in your wood:
Champaign Woodworkers Club 