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there are many teqniques and approaches to measuring rockers, most of the ways that have been touched upon in this thread is not very accurate and precise. it get's you in the ball park but isn't exacting
Aloha Oak
Not sure if my method is among the ones you feel are not exacting enough. I have no desire to waste time in a pissing contest over this issue but how exacting do you think a method needs to be?
The real challenge is customer satisfaction. And as long as the systems used are exact enough to keep the customers happy, then it would appear that the techniques used are precise enough. If customer expectations rise significantly, we will all be challenged to improve, hopefully, at a pace that exceeds theirs.
As you noted, there are many other factors that effect a boards performace. This thread is only dealing with one of them. And that is hard enough to get a consensus on.[wink]
I do agree that you can’t scale all parts of the board equally.
Aloha C
As you can see on Swaylock’s and apparently the shaping world at large, there is a fair amount of confusion regarding the subject of measuring rocker. Even to the point of some believing it can’t be done accurately enough.
If it is common among many, to think that balancing the stick, or some version there of, will give a consistent base line to measure rocker…then I try to head as far as possible in the other direction to make my point. I want to make sure the correct method is totally clear and that the dysfunctional method shouldn’t be confused with it in any way. That is way I emphasized the “no balancing” point. It wasn’t to contradict you. I understood exactly what you had said. I just don’t want your careful and precise use of balancing the rocker stick on center, to be confused with other improper ways of balancing in the hope of getting an accurate tangent line.
Simply pressing the stick on center is the fastest most simple way to get there. If one needs to keep the stick there for an extended period of time then taping, sandbagging or balancing will all work fine as long as it stays on center. I know you know all this. Hopefully everyone else does to.
The main reason I put the measurement marks on my stick is so that I can grab a new blank that I want to shape say a 7’ board from with nose 6.5" rocker. Because of the stick is marked in inches, I can just grab my rocker stick at the 3’6" mark and slide the stick with the ruler at the end until it reads around the 6’5" I will be needing. I can quickly gauge several blanks for their suitability without any other kind of measuring. It is very efficient.
My disagreement with your comment about Rocker Templates was your use of the word “ONLY”. Sorry if I was too picky in challenging that. It just didn’t sound like you were leaving any room for any other method. And the method you seemed to be championing, is way too cumbersome to use. It is so easy to just measure the arch off of the tangent line and duplicate it on the new board. And a list of measurements is way easier to lug around. Ha! As you can tell I am not a big fan of rocker templates. Though some guys like Gordon Quigg use them religiously and quite successfully.
Boscoe was a good friend. I miss him.
Hi Bill
I’ve been using the method of “press the stick at centre” for a while with great success…easy, reliable and repeatable.
BUT
How do you accurately position the apex of your rocker? The method I use is to put the board on the racks in “trim position” and sight it from the side…there surely must be a better way?
This is one of the reasons why the blanks I did for Clark didn’t have a ton of tail rocker in them. They were designed for the shaper to thin the tail as needed by cutting in the tail rocker rather then cutting down the deck on an overly rockered blank bottom.
Thanks for bringing that up.
I see guys come and order blanks with the rocker just right in the tail only to take 3 passes off the deck to get the foil correct
Quote:
Hi Bill
I’ve been using the method of “press the stick at centre” for a while with great success…easy, reliable and repeatable.
BUT
How do you accurately position the apex of your rocker? The method I use is to put the board on the racks in “trim position” and sight it from the side…there surely must be a better way?
Aloha Silverback
To answer your question, I first need you to answer a few questions.
What is the apex you speak of?
Or better stated. How are you orienting the bottom arch in space such that some point will appear to you to be the apex you speak of?
If you can determine what it is, why do you want to know where it is?
Are you using the apex you speak of as some kind of referrence point?
If so, for what purpose are you using it?