How do you measure rocker?

[Headwax.]

electric planes? they are for pansies
I use a belt sander. Or this tool developed by Japanese Sumo Wrestlers for killing cockroaches works pretty well for shaping small concaves.



Beeline I was putting myself in your skin. I notice there is plenty of room


As far as measuring rocker, this is sideways, but I always toyed with usi8ng the garage floor to shape my flat spot. IE place half shaped blank on rough concrete floor and rub it around till you have the appropriate flat spot. (I hear that it works with bald men on bedheads- not that I have any interest in rubbing bald men on bedheads; nor in rubbing bedheads onto bald men)

Avoids rocker twist as well.

Of course according to DRRED flat spots are overated.

Yet I notice that he presents no proof.

Perhaps is it because his rocker measurer can't accomodate them that he dismisses them so readily?



PS Red no you didn't upset me, my last patient finished early and I was bored (and obviously tired)

[Mark Ramirez]

The rocker is the curve of a surfboard from nose to tail, as viewed side-on. Of course, variables such as foil, rail design, and bottom configuration will influence the way a rocker acts, but its hydrodynamic effect is easy to define: less rocker means greater speed and reduced maneuverability, more rocker means greater maneuverability and reduced speed. When boards became lighter, quicker, and faster turning, the rocker was given its due as a key design element, and a board's single most important feature. Many shapers use computer-programmed rocker templates to ensure consistency from board to board. The rocker seems like it's most pronounced in the front third and the rear sixth.

[Beeline2.0]

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[red]

Andrew and Bee,
No wonder I didn't sleep well - I'm receiving a hammering on this thread! I can take it - got a newie on the way today - nothing can dent my excitement.

On flat bits:
Pommie shapes his boards curved at one end, flat in the middle and curved at the other end (a bit like the dinosaur expert in the Monty Python skit - you know - thin at one end, fat in the middle and thin at the other end). The flat is about 2' long. He's going pretty good on them, so I'm sure there's something to it.

But (in order to open myself to a bit more abuse) I think that flats arise out of an inability to generate a subtle enough curve (almost flat, but oh! so subtle). We are talking kneeboards, right?

You got it Mark - rocker"s the key element (and easy to achieve with computer shapes). Because I use thick blanks I have access to almost any rocker I want (simply by tilting the blank) - I'm not limited to the blank manufacturer's templates.

[Beeline2.0]

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[C.P.Odom]

Beeline,

You are so wrong referenceing chalk and axes to shape boards rather than fine cutting tools like belt sanders and power planes.

[Beeline2.0]

..

[hart]

< snipped>

I'm not limited to the blank manufacturer's templates.

Blanks must be ordered to suit your CAD profile..

the biggest blank failure experienced in Sydney right now is the use of inappropriate rocker templates used by computer programmes/ shapers to generate new boards

(..meaning ANY blank I can get my hands on will do type stuff.. )

the end result leaves the consumer at risk..

foam that is cut in ANY way the designer hadn't intended will only result in unsuitable/ unstable foam that then becomes laminated and potentially can collapse/ shrink six months later

so what I have to say this

ANY blank manufacturer will glue-up YOUR blanks to YOUR ROCKER template..full stop

.

and THAT template SHOULD represent whatever you intend to SHAPE

whether you do it by HAND or by COMPUTER..

It still remains your choice but..which is all good

hart



any DECK of any BLANK should be NOT CUT beyond 4MM of its CRUST before you expect failure

so please..get your DECKLINES sorted before you start playing with ROCKERS..or your market

and I'm sorry it took sooo long to get on topic

[Headwax.]

Hart

no need to apologise for being off topic..


being off topic is what restored interest in this thread

mind you, I never lost interest

as someone said elsewhere, you have to mix a little manure in with the soil to get the veggies to grow

see for example GB Shaw in his plays where he lectures to the masses ... he hides the lesson within the entertainment

as opposed to Oscare Wilde who hides the entertainment within the lesson ...

the biggest blank failure experienced in Sydney right now is the use of inappropriate rocker templates used by computer programmes/ shapers to generate new boards Idea

oddly enough, same could be said circa late 78 where non computer shapers were shaping their boards at an oblique angle to the blank surface to avoid the same soft foam problem

maybe it's not just a computer shaper's problem...

[frankfqr]

Thanks for checking in on this one Mr. Hart!!! And a begrudging thanx to the banter for keeping it alive long enough for him to do so . Does the elusive midpoint exist?, and if so, how do you define or locate it? You've provided alot of boards here in the states, so how would one provide stats if they wanted to delve into rocker changes? Do you use any device for measuring rockers or is it all up to the trained eye? Are your rockers ,for the most part, consistently the same? Hope this isn't to much at once...please and thank you....frank

[hart]

g'day Frank

Does the elusive midpoint exist?, and if so, how do you define or locate it?

Not too sure what you mean..if you are talking 'apex' of your rocker..then yes, it does

However rocker curves along the stringer can vary greatly to the curve along the underside of your rail-line

My stringer-line apexes are distinctly behind the centre of weight (release)..while my rail-line apexes are distinctly forward (drive)

Do you use any device for measuring rockers

Yes, I was using flexible aluminium flat bar with threaded-rod offsets for some time since the mid 90's..but nowadays (probably because my rockers are so CONSISTANT)..I measure them rarely

FOOTNOTE: All my foam is glued-up to my individual stringer templates so all my decklines are constant. Considering I cut all my bottoms using the same technique..then consistancy is relatively simple to achieve

hart

oh yeah..and trained eyes yes.. they are your greatest tool ..

[frankfqr]

Priceless!!!It's all being absorbed, thanks, frank.....

[red]

Good input on retaining skin - thanks Bruce
Different to what I'm getting from the machine shapers down here (using several NSW foams), but they might be biased. I'll remind them to cut off the bottom, tx
Do you know whether the same situation is arising with polystyrene, cos that's where I'm going next?
Red

[KneeBumps]

Mr Hart wrote:
My stringer-line apexes are distinctly behind the centre of weight (release)..while my rail-line apexes are distinctly forward (drive)

Mr. Hart communicated more to me in one sentence than the rest of the discussion

Thanks!