Homebrew Spindle

My homemade spindle prototype is coming along nicely.

One problem I'm having is heat.

I'm making the spindle from a Dremel Advantage. Essentially putting all
the components into an aluminum frame, and replacing the 6002V front
bearing with an ABEC-1 rated one.

The problem I'm having is the armature is getting pretty warm, even at
low speeds. I've duplicated the airflow of the original as best I can.
I've also confirmed that there is air flowing through the field and
across the armature. It still gets pretty warm, hot water warm, not
skin-sticking-to-the-shaft warm. Could my new bearing be the culprit?
It feels fine in hand, but I'm not turning it several thousand RPMs in
my hand. I've thought of putting the old bearing in, but the new one
seems to like it's new home on the shaft (i.e. it's tight), and I don't
want to damage it taking it off.


Thanks!

Regards,
JJ

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Help everyone. If you can't do that, then at least be nice.