Best guess?

[Newton Hunt]

Hi Jim,

Get some double sticky tape and attach the felt to a board with nice
90 degree edges.  Attach the felt to the board with the tape and pass
this assemblage through a band saw with a fine tooth blade and cut to
the thickness you wish.  

Or you can attach a tall fence to the drill press table and use a drum
sander to thickness (thinness) the felt that way.  

If the backcheck heads are still turning after applying CA then you
are using too thick CA or not applying enough.  The hole should be
filled entirely with the CA so the wire is held firmly.  If the CA is
working on the capstans be grateful.

Hope this helps.

		Newton