Here we go again,Everybdy I say again,Everybody should be be taught or learn to turn with both handswether they be left handed naturaly,right handed naturaly or ambidexterous(me after having had my left hand put in my pocket at school,then my arm tied so I could remove it,but I still used my left as soo as I got out of school) as in some situations on a lathe you just can`t get in with right handed turning,I know your on a mission to make everyone right handed George,but not everyone wants to be like that and they want to be taught by a competent turner both ways,as to the time issue swapping hands,it can be done literaly in less than half a second,so that`s that excuse out of the window to and I`m a crippled up old flid,so a fit person should be able to do it quicker,if you are just left handed and can`t grasp being right handed you should be taught left handed,and then just practice doing both as much as possible until it clicks,I used to teach apprentices in the dental trade,another place where you need to use Ror L hands for in different situations,some take longer than other,but all can master eventualy even if it takes years.