New Spotz V2 2014

[Kite Rider]

Back on the subject....

So in this scenario raising the AOA of a stabiliser should cause the tail of the foil to go up and thus the front wing will go down

Mmmmm, not quite. The stabilizer (rear or tail wing) of the Spotz has a profile that generates downward lift, that is, the opposite of the front wing, which generates upward lift. If you increase the AoA of the stabilizer, the tail of the foil will want to go down, hence the front tip of the board will want to go up.

Maybe we are thinking the same things, and have our frame of reference mixed up, but I think you're off on this. Let's call positive/increasing angle of attack angles where the leading edge is higher than the trailing edge.

Even if the rear wing is profile shaped to generate downward lift, when you increase the angle of attack enough (lift the leading edge higher than the trailing edge), it's going to create upward lift.

Like a plane flying upside down: http://www.straightdope.com/columns/rea ... pside-down

I may be off on this but in an email exchange I had with a kiteboarding hydrofoil designer last summer, we touched upon the subject of the operation of the foil relative to the front wing, the stabilizer and their respective lift. Here is my English translation of it:

two opposite profiles allow a stable foil: if both wings had an upward hydrodynamic lift, their forces would added irregularly and the foil would tend to "make waves" in going forward, the lift from one of the wing would take over the other alternately, without balance. The downward lift of the stabilizer counterbalances the upward lift of the front wing, creating the pitch-up of the foil (not sure if "pitch-up" is the proper translation for "couple cabreur").

So this is where I am coming from.

Normand

[Hawaiis]

After waiting for one month, I finally got my Spotz foil pitch gauge in pieces.
First class mail envelope is not for shipping foil gauges.

[stefaans]

Haha, seriously. I've shipped a couple of those without issues. How freakin bad did that go. No loss at least. $1 guage.

[Peter_Frank]

After waiting for one month, I finally got my Spotz foil pitch gauge in pieces.
First class mail envelope is not for shipping foil gauges.

What is that ?

A foil pitch gauge ?

Is it the thin metal strip that has to be used for something, and how ?
Or just the ruler having a side break off ?
If so, where is the pitch gauge ???

Otherwise assuming the ruler is the cheapest one could find easily for some "fill and protection" for the gauge strip.

Or maybe not just a ruler, but some specific markings ?
(although it looks like a standard one foot ruler on the photo, or is there some special markings on the back ?)

Really confused now

PF

[BWD]

Why do they not just tell the customer to buy one of these?

[Hawaiis]

If you look closely, there is a dowel at the end of the ruler. The measurements are what we need. So it is important to use the exact same ruler. The fuselage is not square and straight, it is tapered.

[Peter_Frank]

Thanks, now it makes sense, it was not a "straight" ruler

Not even before handled in the mail

PF

[antonell0]

Hawaiis, I don't believe that, with your skills, you cannot build a better ruler. What is important is the measure values and sharing the knowledge about the effect of changing the pitch.
Stefaans, can you share your findings?
I tried several angles with my spotz v2, now I use the less angled configuration in all condition. Will try again when I get the new race front wing.
A.

[Hawaiis]

Hawaiis, I don't believe that, with your skills, you cannot build a better ruler. What is important is the measure values and sharing the knowledge about the effect of changing the pitch.
Stefaans, can you share your findings?
I tried several angles with my spotz v2, now I use the less angled configuration in all condition. Will try again when I get the new race front wing.
A.

We need a standardized center at 40mm on the ruler.
Or the Abbots will be talking to Costellos

[stefaans]

Don't have much to add. I send out these to help guys not at my local spot. each should really dial in their own setup since boards and foot placement also plays a major role. Without this when you configure your new spotz it comes out to about 43mm(by default) which is way too much help from the rear wing. what happens with this configuration is uncontrollable drops back in the water at lower speeds and of course top end lift.
I dialed mine in to 40mm with the small wing, took me a couple hours with the "allen" key in my harness back to the beach every 15 minutes but finally found my sweet spot.

I'm on the bigger wing now and figured i'll detune it even more with thinking the bigger wing has more lift so changed it to 39mm. works fine but too much on the back foot. works great actually but have found that going back to 40 gives me a bit more speed where at 39 i could still point super high but due to all the weight on the rear foot had a loss in speed. very marginal of course. adding some more on the front foot gave a bit more push which equated in a bit more speed with no angle loss and can even go a bit higher at slow speeds.
I know none of these numbers help without this tool. by default most foils i dialed in the range of motion on the rear wing is about 40mm to 45mm where mine can go to 39mm. I guess my suggestion would be to first timers on the Spotz 2 is too angle the wing with the very least amount of angle and detune from there if you find yourself too much on the rear foot.

If you do ride in very light winds it will help to give it just a tad more angle. this help getting out of the water easier and since you really wont be going much faster than 20 to 25knots you wont have too much to deal with.