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I think you need a second piece of lexan (like the one I drew above), but instead of following the green outline, cut it to the blue outline and glue them together. You'll still have the original shape, but you'll have a piece supporting it against the stress of swimming. The tips are far enough away that they shouldn't be too stressed and will stay flexible enough to still look flowy, without snapping off.
Thanks, I'll try that.
Small question though;
Is lexan the same as polycarbonate? Cause every website I found said something different.
It's called polycarobonate, lexan (PC) Polycarbonate and then another few dozen different names.
Lexan is a brand name for polycarbonate. Makrolon is another. Just make sure it's polycarbonate.
How thick is yours? I'm going to order 0.25" (about 12 mm, I think), because the 0.093 just isn't thick enough.
My husband wants to know if it said polystyrene on the label- he said it can look similar, but is not as strong or flexible, and could explain the break.
I don't know, but it seems like the sort of thing I'd do by accident.
I see you're in the Netherlands? I don't know what's available there, but here in the states, polycarbonate costs more than polystyrene.
Here's a video with a single layer paddle shaped polycarbonate monofin. Could yours bend similarly without breaking?
Sorry if I'm pushing the issue too much. I don't want to be obnoxious, I just want to understand what went wrong.
My heels are off the edge of my monofin and it works fine. A lot of commercial monofins also have their heels off the edge, so I don't think it's a problem.
You definitely need to have enough of your foot on the monofin, like Pearlie said, to act as a fulcrum. Just on the toes won't do much, obviously.
I don't believe the heels are the issue though, because it snapped with your heels off the monofin. If lengthening the foot plate creates more power, then the snapping problem becomes worse, not better.
I had a longer footplate, heels on, and it snapped right across my toes, that's why I advocate having your entire foot on the fin.
If you don't like the heels showing, maybe adding some heel fins to hide them?
On land in the air it did, mostly.
In the water, I stood on the bottom of the pool, jumped up a little, wanted to do the first kick, and 'CRACK' it said.
I have no idea what it said on the label, I bought it two year ago, almost had a chance on making a tail myself,
pulled the label of, and never was able to make the tail.
My feet were quite far on the fin I think.
(what is a fulcrum?, never heard that word before...)
Oh, my sheet was 4mm thick, maybe 5. Wa that too thin?
noun, plural fulcrums, fulcra
[foo l-kruh, fuhl-] (Show IPA)1.the support, or point of rest, on which a lever turns in moving a body.
That's it! Your sheet is way too thin!
Maybe the description can help?
http://www.amazon.com/Lexan-Sheet-Po...arbonate+sheet
Also, I went back and looked at your photo of your fin...what broke off of it? Polycarbonate wouldn't break like that. I think you had Plexiglas (Perspex), that's a regular acrylic sheet and will shatter easily! You're lucky you didn't get cut!
Yeah that helped, Thanks! Thanks a lot!
But the extra reinfocement also needs to be 12m thick?
I'll read the answer tomorrow,
it's bedtime here in the Netherlands, and my boyfriend really needs some good sleep (and so do I)
Naw, I'm thinking 12mm total thickness. Good night :bed now:
Following your thread :-)
Good luck on this journey!
This is a really informative thread! Thanks for posting your progress (and thanks to those helping with suggestions), will be subscribing to it. :)
Thanks for all the help and interest for this makeover project.
I told my dad the what the problem most likely was (he seemed interested while he listened and helpful)
and gave the suggestion that I might have to take a look and ask a glass-company for a sheet of Lexan (or 2)
We also figured out that the former monovin sheet was Acrylate(?) and not Poly-Carbonate.
I measured the former sheet and it was 3mm thin...
I took picure of the snapped footpockets but I don't have a phone-USB cable so I can't upload it right now.
And we have a really, I mean really really, flexible sheet of plstic laying around now,
a protective sheet for the floor from under my desk which we removed today.
My mom joked but making it a monovin, but think maybe I'll try it sometime.
Even though in won't snap, it'll most likely not work, but I'm curious if it still is a little bit useable.
Fun side project eentually.
I was actually going to suggest that you use a really flexible piece of plastic to fill out your shape- so if you make your monofin the paddle shape, you use the flexible plastic to make the tips. It won't add any power , but it might give you a nice flowy effect :)
That's a really good idea, I was about to suggest the same. Those carpet protectors are often made from polycarbonate, too, but not the same as the sheet kind we are using for fins. (But sometimes, they are made from a clear, hard rubber, too).
I'm glad your dad is interested in coming up with a solution!
Last weekend I said I had a few pictures. Now I have a phone cable,and can post them for you to see them!
I forgot to show you pictures of the whole finished fin before it broke:
Attachment 25195
Then I went swimming and the fin broke right at the footpockets.
I don't have the orginal broken fin, I only have the footpockets left but I still have the paper line out so you can see were it broke on the Acrylate fin.
Attachment 25196
Attachment 25197
Attachment 25198
Ouch!
I would make a footplate (red) out of polycarbonate and attach it to the softer piece (carpet protector) in the shape of your final fluke. This way, you get propulsion without breakage, and a nice, flowy finish to each kick through the water.
Attachment 25202
I have been thinking, if I attach the flexible plastic to the 6mm polycarbonate,
I will never get to 12 mm thickness, since the flexible floor protection is only 2 or 3 mm thick.
That would be a total thickness of 9mm, would that be thick enough?
(Also I'm talking in millimeter out of centimeters. Don't know for sure if inches have mm too)
I haven't been able to do much work on my tail, the weekends at home were pretty busy with other stuff I had to do.
I realized that 12mm is about .5 inches thick and that's probably too thick! I got polycarbonate that's .25" thick... which is around 7mm (26mm = 1 inch). I think 9mm should be plenty.
Good luck!