I spoke recently to somebody who avoided self spacing frames because he was
intending one day to use an automatic uncapper.  I have myself been using
self spacing frames, and may one day wish to use an automatic uncapper.

Do the shoulders on self spacing frames cause problems for automatic
uncapping machines?

Frank.
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The very act of seeking sets something in motion to meet us;
something in the universe, or in the unconscious responds as if
to an invitation.  - Jean Shinoda Bolen