I have a variable speed Delta drill press with this type of speed adjustment
and shortly after I bought it the steel insert in the middle of this
aluminum pulley pulled out of the aluminum. This caused a different type of
failure, but I got to inspect the way it was made real well. You've got to
figure out why the top pulley doesn't move, maybe it needs some lubrication,
etc. Those pulleys usually have a kind of spline in the sides facing the
belt. As the sides move together these splines mesh which allows the working
surface (where the belt touches) to move higher toward the outer edges.
Maybe there's something stuck in one of the splines, perventing the mating
spline from meshing, or maybe the steel insert has rotated in the pulley. It
also has a spline that rides in a spline on the shaft and if the pulley
spline and the shaft spline move in relation to one another the pulley
splines may be hitting each other and not meshing like they are supposed to.
The spring pressure has to be removed and then a careful inspection of the
pulley must be made. Only then will you be able to figure out what is
causing the binding problem.
"pankr003" < firstname.lastname@example.org> wrote in message
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