How to measure depth of a mouthpiece?

[bort]

Is there an easy way to measure the *depth* of a mouthpiece?

All I can figure is to take a piece of clay, play-doh, or something like that and make a mould of the inside, and then measure that.

Is there a way to do it without sticking "something" down inside?

Thanks!

[oedipoes]

Take a small ball of known diameter, must be bigger than the mouthpiece bore
roll it into the mouthpiece
measure distance from rim to ball with depth gauge or alike
add known diameter of ball to this dimension
done

something like that, probably depends on how you define depth...

[UDELBR]

Quick and dirty rough for estimation: put quarters in the cups of two mouthpieces for visual comparison.

[tubapix]

Quick and dirty rough for estimation: put quarters in the cups of two mouthpieces for visual comparison.

Been doing that for years. Works when comparing depth on like mouthpieces - i.e. funnel to funnel or bowl to bowl.

[smitwill1]

I measure the total mouthpiece depth either with an improvised rod (i.e. small pen, knitting needle, etc...) or with the depth gauge on a caliper. Then, measure the depth of the shank. Subtract shank from total and there you go...

[bort]

Very clever, thanks guys!

[iiipopes]

When you take a typical ballpoint pen and put it into the bottom of the cup, you can see where the mouthpiece cup starts to spread at the junction of the cup and throat. Since everything is on a curve, it is a guess at best, anyway. Hold the pen perpendicular to the rim, use your thumbnail and hold it up to eyeball it to gauge where comes to the top of the cup before flaring out to the rim (what trumpet players obsess about: the "alpha angle") and measure from the thumbnail to the point near the tip of the ball point pen where it seats in the transition curve. That is quick, cheap, dirty, and about as accurate as anything else.