Foot pockets

[loupitou]

Hi all,

I'm building some monofins baldes on my spare time to experiment materials (carbon fiber Vs fiberglass), design (blade length, width, number of layers, layer optimization).
So far, I've always glued my blade to a standard footpocket (like this http://www.fins4u.co.uk/products/Freediving%20monofin%20sport%20carbon/freediving%20monofin%20sport%20carbon%20upright.jpg)

But this isn't very convenient for swapping the blades, plus I can't change the angle of the foot to blade.

I was thinking of using the concept of lunocet (i.e. bicycle shoes http://forums.deeperblue.com/attachments/monofins/28736d1276637735-new-lunocet-img_1995.jpg) or maybe the DOL-FIN (here).

I like the DOL-FIN system because you can simply adjust it and hence share your mono with other people but I'm afraid you can't get a good foot-pocket to blade link.

For the bicycle system, I'm concerned about the back of the shoes rubbing against the achille's tenon when the foot is extended.

Overall these solutions are very flexible and would let me change the blade/foot angle easily but because of the gap between the top of the foot to the blade, maybe the drag will increase as well.

Anyway, if you have tried the lunocet and/or the dol-fin maybe you can help.

I'll share the blade construction process later on when I'm done repairing my vacuum bag

Happy freedive for all

 

[Zmagoj]

Hi,

I am interested in your building approach.

Maybe you can find my threads usefull.

http://forums.deeperblue.com/bi-fins/86109-selfmade-fiberglass-fins.html

and

http://forums.deeperblue.com/monofins/87121-selfmade-monofin.html

Keep us posted.

 

[loupitou]

HI Zmagoj,

I have of course read your two post with great interest. However as I stated my "task" here is to build a platform to test several blades and ultimately be able to swap blades on the fly with minimum tools : having one blade for traveling that fits in a std luggage, one for deep dives, one for training in pool (distance), one for snorkeling with friends, a narrow one for cave diving...

Anyway here is my (chaotic) approach :
* I bought a pair of bicycle shoes
* I've determined the angle between the foot to the blade I want was 20deg (based on a lot of internet reading and a picture of me swimming with my "flat" monofin)
* I transferred the shape of the shoe to a piece of wood (laminated 2x4)
* I cut the profile away and then traced the 20deg angle with the connection point of the shoe to the blade to be the center of the foot arch (may need to adjust later).
* I cut the 20deg ramp that will hold the blade then shaped the block of wood to be less, hum, "blocky".
* I sealed it with two coats of shellac and wax then place it in a frame and poured plaster to make a "negative of the block"
What I need to do now :
* use some cut-offs of my blade fiberglass to make a lamination in the mold. I need to keep holes for the screws
* place cynlinders to allow access to a screwdriver around the screws connecting the shoe to the "wedge".
* Then place some foam in the mold, place some nut inserts (for the blade to connect to the wedge) and pour epoxy.
* Finish the blade (my vacuum bag has a leak right now )
* screw the shoe to the wedge and the blade to the wedge

I will keep you posted on my progress

One question to you Zmagoj, what material do you use for the vacuum bags and to you re-use the bags at all ? I've purchased some - expensive - mold released impregnated polyurethane and I cant seem to be able to seal the edges !

 

[Zmagoj]

Interesting approach.

Buy this for sealant:
acrylic sealant - Iskanje Google

It is used for sealing windows, pipes... should not cost more than 2 eur per tube.

Look at the price:
NAKUP.MERKUR.SI

The bags are from cheap PVC, which you can buy in a garden oriented store - 1 eur /4m2. After use its garbage.