Quote Originally Posted by m_c View Post
If it wasn't making a noise originally, then it's unlikely to be anything stepper related.

Now don't take offense at the following questions, but I like to cover the basics.
What bearings did you fit?
Support block should be two angular contact 7xxx series bearings, not standard deep groove 6000 series.
And did you fit the bearings the correct way around, with outers races opposing/inner races facing?
And did you adjust the preload correctly?
This is what i was going to post, I'm going to say 100% on the bearing's and:

Quote Originally Posted by m_c View Post
And did you fit the bearings the correct way around, with outers races opposing/inner races facing?
To clarify the Bearings, in back to back configuration:
Back-to-Back angular contact ball bearings provide a rigid, high-capacity arrangement capable of supporting heavy radial loads, tilting moments, and axial loads in both directions.

These bearings are ideal for applications requiring precise axial positioning, such as spindle bearings or high-precision machinery, with load lines that diverge towards the bearing axis, increasing stiffness.

Key Features & Advantages of Back-to-Back (DB) Bearings
High Rigidity: Excellent for supporting overturning moments, suitable for high-speed precision applications.
Bidirectional Axial Load: Handles axial loads in both directions, where each bearing handles one direction.
Matched Sets: Often supplied as a set (e.g., 7005CD/P4ADBA) to ensure precise preloading and accurate assembly.
Common Back-to-Back Arrangements/Designs DB (Back-to-Back): Designated by "DB" (e.g., 7005CD/P4ADBA), with load lines diverging.
Double Row: The 3200 and 3300 series are standard options.
.

My advice is, don't by cheep ones, I've had to buy proper radial bearing shims in the past to get them preloaded properly...

Single row deep groove ball bearings vs single row angular contact ball bearings.