All you have to know is a straight line intersects a curve only at one point and we use center as a reference. It doesn't matter if the board is glued to the wall as long as the straight line intersects at the center point you will get the same measurement
Money! Thanks. This is why I shouldn't be measuring with the board on the flat floor? Because the weight of the tail/nose could alter the fulcrum? So if I use a bar I can measure from center... love it. Thanks.
Awesome explanation! Thanks for sharing. Would love to hear more about maintaining intended fin cant when installing boxes on boards with deep concaves. I'm guessing a rigid and thin straight edge could be used together with the fin cant angle tool. That's just speculation though, would be interesting to know what's actually done in practice.
Matt: what do you use for the straight edge? I can't seem to find anything straight. I got an aluminum 96" square from City Mill that looks like yours but it has some bend. Perhaps, at that length, it doesn't exist?!
Hey master Matt, Happy new year! Quick question: Moving the straight bar 3-4 inches back or forth changes the numbers a little bit, which sometimes can be helpful. Apparently this changes the center of the board/center of curvature relationship. Is there any "formula" telling us how moving the center of curvature affects the boards characteristics? Thanks!!
Yes, moving the bar will drastically change the numbers. That is not really a negative because all we are doing is plotting a curve and as long as we do the exact same measure points on the board we are shaping then we are fine. I don't move the bar from center because I understand rocker as a curve tip to center on both ends.
All you have to know is a straight line intersects a curve only at one point and we use center as a reference. It doesn't matter if the board is glued to the wall as long as the straight line intersects at the center point you will get the same measurement
Money! Thanks. This is why I shouldn't be measuring with the board on the flat floor? Because the weight of the tail/nose could alter the fulcrum? So if I use a bar I can measure from center... love it. Thanks.
great stuff this is very logical makes so much sense thanks love it.
Thank you,
Master teacher
Awesome explanation! Thanks for sharing. Would love to hear more about maintaining intended fin cant when installing boxes on boards with deep concaves. I'm guessing a rigid and thin straight edge could be used together with the fin cant angle tool. That's just speculation though, would be interesting to know what's actually done in practice.
Matt: what do you use for the straight edge? I can't seem to find anything straight. I got an aluminum 96" square from City Mill that looks like yours but it has some bend. Perhaps, at that length, it doesn't exist?!
Probably a dumb question, but what pencil do you use for drawing outlines? My #2 doesn't do much, and sharpies seem to die from foam dust.
Hey master Matt, Happy new year!
Quick question: Moving the straight bar 3-4 inches back or forth changes the numbers a little bit, which sometimes can be helpful. Apparently this changes the center of the board/center of curvature relationship. Is there any "formula" telling us how moving the center of curvature affects the boards characteristics?
Thanks!!
Yes, moving the bar will drastically change the numbers. That is not really a negative because all we are doing is plotting a curve and as long as we do the exact same measure points on the board we are shaping then we are fine. I don't move the bar from center because I understand rocker as a curve tip to center on both ends.
What do you do if your rocker bar is shorter than your board?
You can tape tongue depressors onto the ends or you can sight it from the tail but that isn't as accurate