Tube OD 1.5" id 1.0" ... 3 mm wall ... not at least for me - bit too thin. Although I have some elder spindles made by famed makers wheres this wall even thinner.
Perhaps for some kind of hobby, then even aluminum is OK and no needs to spend money for ACSP bearings, but for serious job - I do not. Experience says you will tear your hair when detected that your neatly made piece is not rigid and goes easily to resonance, this is especially ailing because spent some AC super precision bearings.
This is just my opinion.
Sure enough there you can see very different opinions and understandings about:
Can RC Brushless Motors be used as Spindle Motor ???
High Speed Spindle for SIEG X2 Mill - getting technical
Speaking of spindles
My homebuilt spindles
And dont select wrong motor!