spindle cross section view

[coredump]

Thats the bit thats confusing me as there are plenty of designs like that but the manufactures say dont do it. The locked bearings should be at the bussiness end and free floating bearing at the other,

Deckel do the opposite: free floating (needle bearing) at the nose, locked bearings (dual andular ones) at the end. This allow very sturdy spindle with a short distance between nose and bearing (almost 0 since the needle bearing is outside the taper nose).

[Jonathan]

Deckel do the opposite: free floating (needle bearing) at the nose, locked bearings (dual andular ones) at the end. This allow very sturdy spindle with a short distance between nose and bearing (almost 0 since the needle bearing is outside the taper nose).

I might be being pedantic, but surely as the spindle heats up the shaft will expand and push the cutter down slightly further. Clearly won't happen if the fixed bearing is near the chuck. Negligible?