Potential new fins

[T.S.Davis]

Hey guys. Not a new product at this point. Trying to convince one of our guys to produce these. He's already made a number of them for some of us. They're CNC cut and CNC bent. These pics are of one for P sport and one for my scale.

The P sized fin is .035 at the curve and then .075 above the water line. It's layered stainless that is somehow laser welded so the two layers are one object. The process was over my head.

Despite me telling him they rival Virginia Craftsman, I haven't talked him into producing them. Think there would be enough interest?
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[MarkF]

I would buy some to try.I use a curved turn fin on my P speck hydro and like it.

Mark

[longballlumber]

Stainless, what grade? - How difficult are they to sharpen? I am only theorizing but, you would probably want to incorporate some sort of shearing/kick-back system with one of these. I would suspect hitting something with one of these is going to inflict more damage overall? Interesting to say the least.

[RayR]

I would be interested. I think most guys running P-Sport would be interested.

[T.S.Davis]

Stainless, what grade? - How difficult are they to sharpen?

I'm not sure on the grade. They do take some effort to sharpen. I used the belt sander without too much agony. Just prototypes at this point. Pete threw one of the P sized fins on his Pearl and gained almost 1.5 mph over the ones he's been making.

If we can talk him into some sort of production we could design the bracket and even slot the fin for some give in an accident. He's cutting the shape with a CNC laser or something so it's just a couple more shapes to throw at the software. Almost no slag on it at all. The scale fin is slotted. I'm really impressed so far but we're still testing. I wont have a good feel for the P fin myself until I get my Pearl finished. Probably next weekend. Maybe......hopefully.......ugh. Too much to do in the next 15 days or so.

The first scale proto I put on the T Plus this past Saturday. It was too thin at .035 with the reinforcement above the waterline. Folded right over. We were a little too optimistic. This new one is .075 through the hole blade. It's got a ton of hook. Might be too much. Should know within a lap or two if it works.

He did make a smaller one for P limited too. He used the one Tom made for his Whip as the prototype shape. Tom has been running it on his Triton in full P. That boat goes like stink no matter what you do to it though.

[macomb]

I'm not sure on the grade. They do take some effort to sharpen. I used the belt sander without too much agony. Just prototypes at this point. Pete threw one of the P sized fins on his Pearl and gained almost 1.5 mph over the ones he's been making.

If we can talk him into some sort of production we could design the bracket and even slot the fin for some give in an accident. He's cutting the shape with a CNC laser or something so it's just a couple more shapes to throw at the software. Almost no slag on it at all. The scale fin is slotted. I'm really impressed so far but we're still testing. I wont have a good feel for the P fin myself until I get my Pearl finished. Probably next weekend. Maybe......hopefully.......ugh. Too much to do in the next 15 days or so.

The first scale proto I put on the T Plus this past Saturday. It was too thin at .035 with the reinforcement above the waterline. Folded right over. We were a little too optimistic. This new one is .075 through the hole blade. It's got a ton of hook. Might be too much. Should know within a lap or two if it works.

He did make a smaller one for P limited too. He used the one Tom made for his Whip as the prototype shape. Tom has been running it on his Triton in full P. That boat goes like stink no matter what you do to it though.

It is 304 Stainless Steel.
I laser weld the thicker gauge to the thinner gauge, then Laser cut it to shape.
I sharpen them before rolling the hook in.

My thought was the thinner the steel in the water the less drag you would have with the same performance.
I could use any thickness of steel, the .075 and .035 is just what I had here at the shop.

I made a few and gave them to people who would know to see how they work and what changes are needed.
So far I think it has been positive.

I have ordered a sheet of both the current thickness and plan to make 15 -20 of a couple different sizes in the next week or two.

[T.S.Davis]

Kevin, I sharpened up the scale and mono fins last night. The mono fins look like they came out of my knife block at the house.

[NeverEnuff]

I was just running some calcs for designing a turn fin for my JAE, if you would like I could run some calculations to give you a closer starting point for the thickness required? This is what I would need:
Boat weight
Boat max speed
Sharpest radius you want the boat to turn
Width of fin at the mounting holes
Width of fin at the water line
Length of fin from the mounting holes to the end
Length of fin below waterline

Or you could just make it out of 17-4 PH stainless, Yeild strength around 145ksi vs 31ksi for 304. 17-4 PH is heat treatable also which would increase the yield up to around 200 ksi. Can you say knife blade turn fins?

[TRUCKPULL]

Kevin

I would be interested in 2 or 3 fins.

Larry J.

[ray schrauwen]

Cool. Me likes.

[macomb]

Kevin

I would be interested in 2 or 3 fins.

Larry J.

I am working on them this week.
I will let you know what I have at the end of the week.

[macomb]

I made 14 Turn Fins this week.
The material is Stainless Steel 304-2B.
Thick Gauge on top for strength Laser Welded to a Thinner Gauge on the bottom.
Here are some pics.
The one pic shows the thickness difference of the bottom of the blade that is in the water vs an aluminum fin.

[Quietlee]

I would certainly like to purchase one or two and provide some feedback once tested. I can gather some Eagletree GPS data between the old and new fins.
Lee