I recently posted some modifications to the Unimat SL 1000 which is very close to the DB200 design. I too needed a drilling/milling depth gage. I added a digital dial indicator so I could easily reset zero when the drill just touched the part and then use the dial indicator to monitor the drilling depth. Here is the Homemade Tools URL to my posting: http://www.homemadetools.net/forum/m...00-lathe-10111 . I hope this provides some ideas. Also some of my other postings for the Unimat SL 1000 contain other views of the modifications.