Retractable Fin System

[dogbert]

how about talking with some R/C guys. A little servo motor on the fins, and a control somewhere on top of the board or placed on the jacket.

So, what if you had 2 remotes...could make life kinda interesting for the rider if someone in the boat could operate the controls on the board

[Tequilasun]

So, what if you had 2 remotes...could make life kinda interesting for the rider if someone in the boat could operate the controls on the board

I was thinking the same thing.

I have the answer Surfdad. But James will have to re-learn some tricks, as my answer requires 1/2 a kick flip for the revert rotation.

Make the board top to bottom symetrical, then when you do half the kick flip, aka turn the board on its top, gravity and water pressure pull the fins out.

or you could use a windshield water detector (the kind that turn the windshield wipers on, to deploy the servos)

[Surfdad]

LOL - I think a 1/2 a kick flip with a shuv is called a "change your lineup in the glee club"

I really thought the retractable fin thing would turn out to be easy...such is not the case.

[dogbert]

LOL - I think a 1/2 a kick flip with a shuv is called a "change your lineup in the glee club"

I really thought the retractable fin thing would turn out to be easy...such is not the case.

Then forget the surfboard and just ride a skateboard deck

You laugh, but my kids actually tried this. The funny part was that one of them actually managed to get up and ride for about 30 seconds.

[Surfdad]

My orginal idea was to somehow mitigate the forward bias of the fin placement on the Walzer. I LOVE the way the Walzer rides, but when the board is revert, as it is after a shuv, the fin closest to the wake grabs and makes the shuv out very difficult. It's a little hard to see, but if you look closely at the bottom of the board, you can see the one fin is just grabbing the wake, in this picture.

[Surfdad]

This gives a quick view of the fin placement on our Walzer. They are about 13 inches apart and I believe close to 12 inches up from the tail.

The further up from the tail and the further out from the centerline of the board, the easier it is for the fin to grab the wake when ridden revert. The other extreme is to have a single fin along the centerline at the tail. The downside of that is that it reduces drive (down the line speed) and the tail doesn't feel as loose as when the fins are further up from the tail. IMO, a board feels more responsive or lively when the fins are moved forward.

[Surfdad]

I started out just wanting to try a board with different fin positions, such that we could test and see where the best location might be, then listening to all the "HYPE" from the folks in the Lost Surfboards/Placebo camp, I thought what the heck, let's try and quad and see if it really has any benefit.

The end result, so far looks like this:

[Surfdad]

I moved them further out towards the nose, which I think is going to make this board a little too "tight" or unresponsive, well at least when compared to the original Walzer. However, I'm hopeful that the placement of the fins will be such that it allows the board to be ridden revert without hanging up in the wake AND still allowing enough drive that aerials can be done.

I guess all that is missing is some warmer weather

[Surfdad]

As a quad this board had pretty good drive.

[Surfdad]

This is a picture of the board revert with just the outside fins in place. With the fins in this location, there was little "hanging" in the wake. When the fins were switched to the inside boxes, they didn't hang at all.