Need advice on how to use bottom blade grinder

With the blade / bed knife mounted on the sole plate, the operator has to slide it past the grinding wheel , but with a degree of operator practice / skill  can do both the front and top edges. Some practice with a “ not too important” blade and a well dressed stone is worthwhile. Never used one myself but back in the 80s a nearby business had one but replaced it with an Atterton Anglemaster that needed less operator input to achieve an accurate and consistent result. 

Either way, a lot better than none , and to quote another forum contributor “ you wouldn’t sharpen one blade of a pair of scissors - would you ?”  Even after fitting a new blade / bed knife, I always give them a light skim and it’s amazing how many new blades , both oem and pattern , have the odd dip or bump . There again, not all sole plates are flat !

Thanks for advice.  Got two blades recently, one was ok and other had bumps.