John, I hope you ''get it'' now that surfding did a good job of explaining it. A bottom rocker is just a 2D curve in space, it doesn't matter where you locate the reference line. The curve stays the same. If you're measuring rocker while handshaping, going off center is the standard. But it's easy to translate #s from a ''tips-level'' measurement to ''tangent-center'', as surfding says. And you'll get exactly the same curve.
Surfding - thanks for the drawing - sweeeeet! The rocker and cross-sections are very helpful, the planshape is awesome! Love it, and really do thank you for taking the time and effort on that.
Hi John: pretty standard is ZERO CENTER. However I have learned over the last 6 years to use TRUE MATH. This comes from working with PhD's of Math and Physics. They work in true values so that the translation in to G-Code can work with a Multiple Axis Machine. There is a Technic that Phil Edwards would use that is more in line with TRUE MATH were he would maintain the nose and tail at ZERO then proceed to take the numbers every 3" from a Level Horizontal Line. The same way the Academics do it. These are only expressed numbers however the rockers will be the same between ZERO CENTER and TRUE MATH. For example I have taken a rocker stick profile generated by a well know shaper that works with ZERO CENTER just like BB. I scan his board (TRUE MATH) and generate a rocker stick profile from the program file and low and behold they match dead even. However the values are expressed differently. Knowing the translation between the two has been very useful dealing with various shapers. It's only a matter of expressed values.
Don't really know if this kind of information is useful here on swaylock?
"and you're worried about where the reference line is on his rocker?"
Yeah, you're right.... 5.9" vs 3.29". No big deal. LOL
Zero center is pretty standard from what I've been reading around here. Apparently it does make a difference.
Take a tip from Bill Barnfield.
John, I hope you ''get it'' now that surfding did a good job of explaining it. A bottom rocker is just a 2D curve in space, it doesn't matter where you locate the reference line. The curve stays the same. If you're measuring rocker while handshaping, going off center is the standard. But it's easy to translate #s from a ''tips-level'' measurement to ''tangent-center'', as surfding says. And you'll get exactly the same curve.
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Surfding - thanks for the drawing - sweeeeet! The rocker and cross-sections are very helpful, the planshape is awesome! Love it, and really do thank you for taking the time and effort on that.
I'm still looking for photos or info on fins.
Wow! Full 70's outline. Had many boards like that in 77' on the North Shore. Easy to ride. If you do a single fin I have the template.
Kind regards,
Surfding
Sleeping on the job!
surfding sleeping on the job.jpg
SUP EASY.jpg
You must be dreaming some sweet dreams, Mike, don't you?
Kind regards from France. Guilhem.
Thanks for stopping by while you and your daughter were un California.
All the best!
Michael
reduced rocker for the Cali Gun
Lopez Style 7'1 (use a US 73A Blanks)
California Gun Reduced Rocker.jpg
Huck Lopez.jpg
Hi John: pretty standard is ZERO CENTER. However I have learned over the last 6 years to use TRUE MATH. This comes from working with PhD's of Math and Physics. They work in true values so that the translation in to G-Code can work with a Multiple Axis Machine. There is a Technic that Phil Edwards would use that is more in line with TRUE MATH were he would maintain the nose and tail at ZERO then proceed to take the numbers every 3" from a Level Horizontal Line. The same way the Academics do it. These are only expressed numbers however the rockers will be the same between ZERO CENTER and TRUE MATH. For example I have taken a rocker stick profile generated by a well know shaper that works with ZERO CENTER just like BB. I scan his board (TRUE MATH) and generate a rocker stick profile from the program file and low and behold they match dead even. However the values are expressed differently. Knowing the translation between the two has been very useful dealing with various shapers. It's only a matter of expressed values.
Don't really know if this kind of information is useful here on swaylock?
Kind regards,
Michael
(Surfding)
Very useful, keep posting.
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