Got my Speedboard fins back from the fabricators Friday and must say I'm very pleased with them. I decided to go with Titanium to save a little weight all though with a board like this it's not really the critical factor, but for shear durability and strength it cant be beat, moving over 10cm of water at 40 + knots you are bound to hit the deck now and again so the Ti should help keep the knicks down to a minimum. This will be my first speed board so it will be a learning process the whole way but from what I have seen and read the shape should be ok. There are a lot of radical fins designs out where I must say and a lot of this speed thing is still very experimental with new board and fin design coming through all the time. People also seem to be playing their cards very close to their hearts so coming by any info is also very hard, I on the other hand like playing open cards and learning from my mistakes who knows maybe there is a Hydrodynamicist lurking around the boards that might have some ideas he/she is willing to part with..... I await the PM
I'm still going to foil them down a little they are not perfect, but I doubt I will ever get them 100% unless I draw up a CAD file and put them in a 3 axis machine. For now I'm happy to use a belt sander of sort and get the cords to my liking although they are not that far off. you are never going to get Ti to a mirror finish like Stainless steel , which is what most of the guys are using looks like it. As you can see from the pictures the dark shinny finish is how they came from the fabricators and the satin finish is what I ended up with after about 4 hours of water papering. My fingers are raw but I'm happy with the finish, I managed to get out all of the buffing marks and the matt finish tend to exaggerate the tiny peaks and troughs where the foil is not perfect which in turn helps with finishing of the shape. I have about 1,5mm of meat both sides of the M4 bolt holes that I can play around with getting the shape right, this would also help save some weight in the end. I had two made up one for a mate we are going to play around with them maybe even shape something different from these two.
I was curious if any of you had any info regarding the physical shaping of fins Google does not offer up much info.
Dimensions
Length : 200mm
Height: 30mm
width: 6.6mm
Weight: 115 grams , for comparison average G10 carbon reinforced fin is around 60 grams.