No offense to DVR owners, but why take the chance? If you are going to have a large seminar, spend good money to bring someone in, why take the chance of it all going to pot? One small electronics glitch can just mess everything up. If you use a Teknatool product how about the
3000? With a decent variable drive and motor it does everything the DVR can, and do it very reliably.If you really want to be anal about a backup just have a spare "stock" 1hp motor and you can switch it out in minutes and have your demo guy turning again before you finish a cup of coffe.I really liked mine when I had it but sold it to get another very reliable lathe but "super sized", a Vicmarc VL300 longbed. Maybe just go with Vicmarc, I have never heard anything bad about them (one of the reasons I got one) and so far all reports have been right on, smooth, solid, everything works well without fuss. Just my opinion, Guy