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Squaring Tolerance


mjshp
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Went to check twist and square, there is shy 1/16th difference in the centerline to outer edge of the hull, and the similar shy 1/16th from transom corner to bow.

Is this shy 1/16th small enough to call it good or should try to work it out?

What other dimenions should i measure to check the squareness and for twist?

Thanks,

Michael

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What you need to check is the straight distance from the stem to the corner on each side of the transom where it meets the shear. This will tell you if the hull is square. As you're working from a kit, measuring around the outside of the shear on each side won't work. You already know that the panels are the same length. You can check the symetry by pulling a line from the stem to the center of the transom at the top. Then measure how far the shear on each side is from the line you pulled into place. Measuring from the same point, these measurements should be the same.

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Thanks for the clarification and help.

The stem to sheer at the transom is less than 1/32 in difference port to starboard--this is measued with the boat level port-starboard. The centerline string to sheer at the nesting bulk heads is >1/32 but <1/16th, with the little extra on the starboard side.

Thoughts?

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PAR is on target. 1/16" ??? I usually use metrics so we're talking about 1.5 mm. I'm not sure my semi-feeble eyes can read a scale that close. Well, I can and do it all the time when dealing with small measures like a 7mm x 14mm strip of wood, but for the entire boat? Hey, getting that sucker within 1/16" is cause for celebration. Well done!

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Went to check twist and square, there is shy 1/16th difference in the centerline to outer edge of the hull, and the similar shy 1/16th from transom corner to bow.

Is this shy 1/16th small enough to call it good or should try to work it out?

What other dimenions should i measure to check the squareness and for twist?

Thanks,

Michael

You get the prize for the best alligned boat in the class. A gold star.

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My boat was about off square about the same amount, and I have to say that I do notice a difference in performance. She pulls slightly to port when on a broad reach, and over a distance of 10 nautical miles, I find she's wandered a good ten feet off a straight line. It's not so bad in the northern hemisphere when the Coriolis Effect cancels it out, but it wreaks havoc when rounding the great capes.

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After the completion of a 36' powerboat hull shell (plywood lapstrake over frames) I won a bet she'd be under 1" in max beam difference. Measured from keel centerline, to underside of the sheer strake on each side, the hull was 7/8" wider on starboard then port. I won my 5 bucks and it was considered an exceptionally tight tolerance build. A short 1/16" oh pleeease, you're just showing off . . . :rolleyes:

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