The question of which brand, type of specs in particular with regard to bearings to use in a Mandrel Saver is a really interesting exercise I scoured the specs of all the bearing manufacturers its a fallacy to assume there is little or no regard to end thrust in a straight bearing which I ended up using in mine for two reasons an angular bearing or thrust race is rarely made in this size and if it is costs the earth, replacement is easy.
My lathes ie two of them use angular bearings or thrust bearings ie the VL100 and VL150 others dont and the life expectance of either type is long in service. Replce bearings for the USA Mandrel Saver from my local Bearing supply guy fitted in the (Precision Saver) was peanuts.
Peter.
