OCD rigging question

[Steven M-M]

If the left over right height differences in built into the sculling rigger, how do you make sure the span is equal on port and starboard side? I know that once you measure the total span from pin to pin (which shouldn't be effect by the built in height difference) you then measure from the outside gunwale to the pin to make sure of equal distance. Wouldn't the built-in height difference make a slight difference in this measurement? If "yes," how do you change the measurement?

The difference may be way too small to worry about, so the correct answer may be "don't worry about it."

[KiwiCanuck]

I haven't done the math but the difference will be small enough that it's likely less than errors most of us will make measuring.

[Steven M-M]

Thanks, K-C (aka W). As you say, likely within any margin of error, so maybe the problem is OCD, not rigging....

[KiwiCanuck]

Well, then... Got some CAD time at work...
We (in Canuckland) tend to rig about 10 mm higher on the starboard (bow) side than on Port (stroke)..
If a single is rigged at 160 cm spread (1600 mm, or 62.9921 inches), and you measure with the slides level from the portside to a position on the starboard pin which is 10 mm higher than the portside starting point, you'll measure 1600.03236 mm, or 62.9934 inches - according to MasterCam7 (probably get the same results using some trigonometry but this is quicker and easier for me).

Conclusion? If anyone claims they can feel the difference of .03mm when they're sculling, I call "princess". Measuring out from the middle of the boat to a 10 mm difference in height may double that error but still... really? I know I can't measure that closely...

With respect to HOW to measure side-to-side accuracy (i.e., if your pins are equidistant from the centreline of the boat). I don't like measuring from the gunwales - although boats are better built than before for accuracy, I've measured more than a centimeter different distances thanks to the gunwales being not equally "spread". I prefer to measure out from the slide on the opposite side of the pin. The error may be a little more than described above due to the steeper angle from the slide to the pin, but the difference between them is still insignificant. (e.g., if you're measuring the port pin, hook your tape over the starboard slide in line with the starboard pin. See what it says, and repeat on the other side. This allows you to see if the pins are centered on the sculler (assuming he/she sits straight and the boat's balanced). Maybe you'll have a mm of error, but do the math and compensate, if it's that important.

Now... I'm in the middle of a tornado warning - although it's flat calm here at the moment, I'm going to watch the sky...