The idea is simple - support a flexible sheet with rigid spars.
In practice there are some complications to overcome, i.e.
- Shaping the spars to include a rocker component
Placement/shaping of the spars to support the sheet edges and leave room for boots/pads
Bonding the spars to the sheet
I consider this build a prototype, and therefore wasn't too critical about the material used. I sourced the following from my local Builders Express:
- Perspex (acrylic - PMMA) sheet: 1400 x 450 x 4 (mm)
Aluminium sheet (I assume 1200 0 alloy): 1400 x 50 x 2 (mm)
Aluminium blind rivets: 4 x 10 (mm)
The next version will probably use 5083 alloy and polycarbonate sheet, and I'm considering methacrylte adhesive instead of rivets to bond the pieces, depending on whether the rivets cause notching/cracking.
Anyhow, for the board shape I simply traced the outline of my LF Harley wakeboard, and cut it with a hand held jigsaw.
For the aluminium spars I traced the rocker outline, cut it with a jig saw, and bent it into shape with a vice and a hammer.
Polished all the edges and drilled 4.2mm holes 50mm apart to join the spars to the acrylic sheet with the rivets.
Attached my LF Vantage boots with bolts directly to 7mm holes drilled through the acrylic sheet.
Total build time was about 10 hours.
Board specs: 1400 x 450, 8cm continuous rocker. Deck weighs 2.9kg.
For comparison, my LF Harley Grind deck is 3.7kg, and my carbon split kiteboard deck (128 x 40) is 2.8kg.
So how does it ride?
Well I took it for a spin at the local cable park today and am pretty stoked about it! The ride is really smooth and stable and it edges really well. It's more flexible than any of my other boards so it doesn't pop much but it seems to handle chop quite nicely.
I've done a few raley launches off the dock and a couple of ollies and it seems pretty robust. Haven't done any kickers or sliders yet but have gone down hard after catching an edge - so far nothing bent, broken, ripped out or cracked.
Only bummer is swimming in with the board requires you to keep hold of it. It does not float!
I'll post some more detailed pics of the build if there's interest..
First dry run in my back yard
First wet run at the cable park