Messages

436

Foil SUP / Re: Diy sup foil

« on: April 12, 2018, 07:38:26 AM »

A noticeable benefit of using both an endoskeleton and an exoskeleton is the ability to make very thin wing sections with considerable strength.  Anyone have experience with longish winglets?  I can always grind them back if they prove to be of no benefit.  Next step is vacuum bagging some carbon onto these wings.

437

Foil SUP / Re: Diy sup foil

« on: April 04, 2018, 12:14:27 PM »

just wet it out, let it cure, cut to shape, drill it, glue wing profile template to anhedral form, lace it.

438

Foil SUP / Re: Diy sup foil

« on: April 01, 2018, 11:48:48 AM »

Great idea about using cured rods of 48K tow bent over to form curves.  Ill have to try that.  I also have some 2mm coremat which would make great stuff for wing profile templates instead of using plywood. 

439

Foil SUP / Re: Diy sup foil

« on: April 01, 2018, 04:11:57 AM »

I tried the CAD thing but I found it to be a waste of time since I already know what I'm aiming for.  I just draw up planshapes according to the surface area I need and use different thickness wings based upon their use.ie - behind boats, large waves, small waves, river waves....
My goal was to create a strong wing as quickly and inexpensively as possible in order to test and tweek.  Without using carbon I can create a usable  wing for what I'm guessing is about $30-50.00.  If you are lucky , carbon fiber 24K tow can be found in large 4 lb rolls for $30-40.00.  This one roll could probably make 30 wings?  Maybe more?

440

Foil SUP / Re: Diy sup foil

« on: April 01, 2018, 03:25:49 AM »

I use a tiny bit of cellophane/plastic wrap under the clamps or you could just push a pointed tooth pick of appropriate size into the hole with the cord to pinch it in place.  When cured just cut them off.  I really like the idea of the divinicell wing profiles,  Ill have to try that.

441

Foil SUP / Re: Diy sup foil

« on: March 31, 2018, 12:35:03 PM »

Not sure about the weight since I do not own a very accurate scale.  Probably a little more than a kai go foil due to the increase in structural support.  I have a little play using a non-tapered fuselage insert but I plan on shimming it out some more with some filler.  I like the idea of being able to change the wing position fore and aft.  Gives me something to experiment with.

442

Foil SUP / Re: Diy sup foil

« on: March 31, 2018, 05:35:01 AM »

     Non tapered so that I can adjust the distance between the mast and the wing.  Forward wing  position for pumping, back position for increased stability.  Its too bad all this lacing must be covered up with filler and carbon.  It looks real cool as it is.

443

Foil SUP / Re: Diy sup foil

« on: March 31, 2018, 04:08:38 AM »

     Well, to start you need a form which will follow the anhedral of the bottom side of the wing.  Each wing segment is scroll  sawed from 3mm ply based upon the airfoil shape you require.   The pattern of 1/8 inch holes is then drilled into each plywood wing segment.  Once done, these wing segments are hot glued, bottom down, to the anhedral shaped form.  This holds them in place for the next process.
I use one 24K piece of carbon fiber tow, folded in half and long enough to thread through entire width of wing.  Tie a knot at the folded end.   At the other end  use a tightly wrapped layer of scotch tape to make the cord ends easy to thread through holes in wing segmnets.  Like the hard ends on shoelaces.  Before threading the cord, it must be wet out with epoxy resin.   Slow cure resin helps since lacing the wing will take 3 hrs or so.  Wet out one at a time, thread it through first hole,  then twist the cord 10-15 times before threading through the other holes.  The knot will keep one end in place.  Small clamps, small clothspins or i use surgical instruments kold the other end.  Do it again, until you are done.   So you are threading a very flexible, damp, twisted piece of carbon fiber. Once cured, the entire wing can then be removed from the anhedral form.  be sure not to use too much hot glue.  Just enough to hold them in place.
     With the laced wing removed I then turn it over, bottom side up and loosely lay a piece of wet out 6 oz fiberglass.  It helps to let this glass layer drape down between the wing segments so it rest on the carbon laces. let it cure in this upside down position.
     Once cured,  I then cut out the space in the wing center where I will need to insert the square carbon tube that the fuselage will fit into.  Making sure its square to wing and of proper angle of attack(1-3 degrees) I use a very dense filler(milled fibers, wood flour) to attach cut carbon cords to inserted piece.  Let cure.
     Placing wing back onto anhedral form, I then fill the segments.  The very ends I fill with a high strength filler.  Around the fuselage insert, I use a lighter mix of microballoons and milled fiber,  the rest is 2 part expanding polyurethabe.  It ends up being pretty light since most strength is gained from internal skeleton.
     Sand or file to shape than recoat with microballoons. Keep sanding. You will be amazed at how strong this wing is even without its glass skin or carbon cloth. 
      I then vacuum bag a layer of 6oz fiberglass before adding 1 layer of 3K carbon twill.  Sometimes i omit the fiberglass and just go with the carbon cloth.
      As with all my wings, they tend to be overbuilt and with some experimenting one could build more flex into the system and make them even lighter. 
     Hope this helps!
     

444

Foil SUP / Re: Diy sup foil

« on: March 30, 2018, 05:37:36 PM »

Las one, I promise

445

Foil SUP / Re: Diy sup foil

« on: March 30, 2018, 05:20:40 PM »

I'm getting good at this now

446

Foil SUP / Re: Diy sup foil

« on: March 30, 2018, 05:16:56 PM »

Ahh! One more

447

Foil SUP / Re: Diy sup foil

« on: March 30, 2018, 05:10:03 PM »

One more

448

Foil SUP / Re: Diy sup foil

« on: March 30, 2018, 04:42:35 PM »

another photo

449

Foil SUP / Re: Diy sup foil

« on: March 30, 2018, 04:39:01 PM »

Here is a photo of laced wing.

450

Foil SUP / Re: Diy sup foil

« on: March 30, 2018, 04:04:23 PM »

I,ve made a few SUP foils so far and I would guess most of us wish to find the fastest, easiest and least expensive method to keep experimentation going.  I’ll share some pictures if all goes well with this forum thing since I am new to this whole deal.   From what I’ve read it is also very important to make strong wings that are of very precise dimensions with regards to maintaining the same foil shape from root to tip.   
Using 24K (x2) carbon fiber tow( can be found for $30 for 3-4 lbs on eBay)an endoskeleton is created between 3mm plywood wing profiles.  These ply wing profiles are hot glued onto a mold of desired anhedral.  This keeps them in place while “lacing the wing with these twisted and epoxy infused carbon fiber cords(36 cords per wing,approx)  This skeleton comes out perfect every time to exact specifications.  Once cured the spaces between the ply wing profiles can then be filled with 2 part foam , microspheres with epoxy,  or any other filler which offers the appropriate strength and lightness..  I use 3 different densities depending upon location.  Most is ultralight 2 part polyurethane expanding foam. 
Once all is filled and faired out with microballoons and epoxy the wing is already strong enough to surf.  Sounds hard but compared to many other methods it is accomplished in very little time .  Once wrapped in a layer or two of glass, it is more than strong enough.  So now we have both an endoskeleton and an exoskeleton.  The single layer of carbon cloth I finally wrap or just use alone without the glass is mostly cosmetic.  I just finished 2 wings that took me less time than 1 wing by my previous method.(carved plywood).  I will attempt to post pictures but don’t hold your breath, I’m an idiot when it comes to this stuff.

It all seemed so easy until I tried to attach pictures.  If anyone has any advice, I’d appreciate it.  My files are too large, even for one photo.  I’ll just post my description for now and hope I can post pics later.