Hi Bob and Brett,
It's only taken two months, lol.
You guys have done a lot of work in the interim.
Here are my hacks. This pair is about 8 years old now and are starting to tear. I should have rounded the tips but I got attached to the pixie look and figured there was no negative in them being a bit longer. They are slighly assym. The long cut is so they don't hang over the rail of my kneeboard and drag through turns. They work fine to get me into waves. Had to swim in from sizable Granites in South Oz and they did a good job getting me out of trouble, but I'm not going to win any paddle races.
I've got an unused pair of Hydros somewhere. They are wide at the foot with big edges. I bound that the wave would catch the edge too much.
Definitely have to cut out the heel or they just get ripped off. It helps I always wear booties.
The fin tether is a leash ankle strap through a simple loop of cord. I only need one because I use my leash on the other foot and just loop around that. Foolproof system I've been using for 20 years.
The brand was sold by sports chain but they've gone all upmarket on me. Might have to slaughter a pair of Cressi subs next ;-)
So here’s the foam mold that I’m going to glass over. It will create a sole with both sides angled up and out to grab and hold more effectively that a flat fin. As it’s just the blade and sides I’ll add the heel strap and foot cover later. I’m thinking silicone for both maybe even a silicone lining inside the flipper.
By having both sides angled it should control the water against the blade and direct it more efficiently off the end of the blade rather than washing off the sides.
The sole of the flipper is the same template as the Voit Duck Feet.
The wider top template is from DaFin so I’ve covered some of the argest and widest popular flippers.
im hoping that are more effective design will bring improved performance. If the sides create better drive they may need to be smaller overall.
The other aspect is the shape of the angled sides to give real control for bodysurfing. With increased grip you wouldn’t need to be Cunningham to tube ride. I can see 2 variations of the sides that could work. First putting the area increasing towards the end of the flipper so the sides work like rear surfcraft fins. The second is to put the most area closer to the middle of the length of the flipper so it’s closer aligned to where you have control with your feet.
I’ll try 6 layers of 6 oz first.
In the bag.
It’s a simple vac system. Vac then tube into bag. The tube is perforated inside the bag with an old t-shirt wrapped around it so the holes dont get blocked by the bag or resin.
I’ve found that a longer flipper gives a better response than a wider flipper.
Out of the mold and even with just 6 layers of glass it’s quite rigid but has some torsion so rather than lay another 6 or maybe 12 layers , I’ll first trim it down to shape and then look to specifically strengthen it in certain planes.
The Voit weighs 675g, the DaFin weighs 350g and this glass one weighs 260 but will probably hit the middle ground.
Ive just ‘pool tested’ it and the sides definately give a lot more resistance so it’s holding water better and it feels like it’s shooting water directly out the back. The widest point of the blade end is 9 inches but I think I’ll do another mold just 6 inches wide. Like Bob Green said about the stiffer blades being a chore, this 9 inch size is a lot of work so a smaller version is needed to get it closer to current flipper feel.
I kept the anhedral sides as full as possible. Even in basic water tests you can feel them forcing the water along the flipper.
so I’m doing a new design with a max width of just 6 inches, ( compared to Da Fin at 9 in) using the anhedral sides to create a smaller but more efficient flipper.
Given a few days to think about anything , I come up with ideas like....
being as the downkick is the useful stroke, maybe the blade should be on top of the foot instead of under it ?
but there’s already a lot to do so I’ll keep that ideas for later.
With the new side design to play with I thought why stick to a constant angle ? Why not have the sides grab max volume quickly in the stroke and then direct as much of that water down the blade.
So here’s the new design, a slimmer blade, but with the sides angled out at 45 deg near the foot, and then wrap the sides in slowly closing the flow with the sides up near 90 deg at the end of the blade.
its a bit of a reverse on how flippers work now
The heel strap pulls the foot forward into the foot pocket but the common comment about flippers is poor fit so I figure to make a fitted left and right pocket.
You’re getting there !
I'm getting a clearer idea of where you are heading. I'd go for symmetrical pockets, that way you don't have to worry about having five left feet.
Yes guys , I figured out that while doing a Left and a Right is customising, it’s also double the work. Bob, you’re right, it’s possible to make a universal foot pocket that does Left and right quite comfortably. See pics below. I had a thought about water ski bindings I used many years ago and translated that to flipper design.
i use clear vinyl so I can see how the foot is fitting.
And the last pic is of the latest blade design with the angled sides flared out wide close to the foot to grab water and then standing up vertically closer to the end of the blade to effectively channel the flow out the back.
interesting that the wider the blade is closer to the foot, the greater the force possible.