Hi

I have a really nice maxon brushless DC motor that I want to use as a low power but high power density spindle. So I started designing a spindle and relised I needed to use angular contact ball bearings. However I had no idea how to mount them so I looked around on the skf website and this forum and got more and more confused. Then I had a eureka moment. I have already bought some chinese c7 ball screws with fixed end supports, I thought, I'll just pull them apart and see how they are done, which I did. But when I did I found the bearings inside did not look like angular contacts at all, just plane old deep groove ball bearings. I can't be sure as I have not taken the metal covers of each side of each bearing but the inner races look to be the same diameter both sides with the covers on.

Is this normal for cheap Chinese ball screw mounts or are these particularly bad ones?

Also how can I mount the ER11 collet chuck I have between two 7202 or similar angular contact bearings? I've modeled this up in solidworks but I have no idea if it will work or preload the bearings correctly.

llet