Diy Brushless Spindle

[Villacherman]

Thanks for the replies...

How about if I add a shaft coupling to the stop with a couple of belleville washers? Then using the collet head pressed up against the lower bearing inner race and the shaft coupling, you would get your axial constraint.

I would also load the angular contact bearing in the same orientation (both loaded with "upward" force). This would make the bearings strong in plunge operations, but weaker in operations where the bit is moving up out of the work piece. Would this be a problem though? Most operations are pressing into (down) the work piece.