Bearing alignment is an important aspect of reducing friction and wear in bearings. A small angle misalignment between 2 bearings can have a larger effect than a simple horizontal or vertical translation misalignment. In the MAE 156A kit, the bearing mounts were first lasercut and then the contact surfaces were precision milled in the machine shop. In order to take advantage of these precision surfaces the bolts to the mounting brackets should be tightened while vertical force is pressing the contact surfaces of the brackets into the T slot aluminum extrusion. See figure below:
To see if your bearings are aligned, approximate terminal velocities should be:
For a single shaft attached in-line to the motor, the terminal velocity should be approximately 5200 to 5300 rpm
For 2 shafts connected with a timing belt with 3.8:1 gear ratio and no flywheel, the terminal velocity should be approximately 4400 to 4500 rpm
Bearing Alignment for MAE 156A Kit Parts
For industry application where bearing alignment is a concern, one could use Self Aligning Bearings.