I understand the concept of tolerances, but I'm not sure what tolerance
would result in "no perceptible play," which is what I'm trying to
achieve.

This metal piece that I'm trying to manufacture is intended to be used
to extend the length of a knob on a musical instrument. The metal
piece will be moved a lot in the course of the use of the instrument,
and will need to remain snugly in place over the metal tab which it fit
over, with no perceptible play. There won't be a lot of force in the
direction that would pull the tab off, but there will be a small
amount.

Ideally, I would like to consult with someone who could manufacture the
part for me, who could also help me work all of the minutia that need
to be worked out to get the part to function as I would like it to.

However, if this isn't available or is prohibitively costly, I can
learn how to work out the minutia myself. In this case, I would need
to either:

a) measure the magnitude and direction of the forces that are typically
applied to this part of the musical instrument, and use those combined
with information about the materials being used to calculate how snug
the metal piece will need to be.

or

b) produce a few prototypes and simply test them to see how well they
function. This would be much easier than option (a), but I don't know
if it will be exceedingly costly.



I don't have anything more precise and accurate than a ruler to measure
with, but I know that the metal piece that I'm trying to produce will
need to be manufactured with a tolerance for fluctuation from the
desired dimensions of less than a millimeter.

Any ideas? Thanks very much again

-Max