Chinook 16" tracks

[Surfside]

I purchased the Chinook 16" tracks and was tinkering around for a sound installation through to the deck. The tubes fit like a glove and have not been epoxied together yet. Should come out at 1.5 lbs. Thoughts? Suggestions?

Thanks,
Gary

[PonoBill]

Chinook tracks are milled out of a single piece of injection-molded ABS. They're in Cascade Locks, 20 miles from my house. I got to see how they were made once. Accept no substitute. I wonder what the fuck people are thinking when they use some two-piece POS in their boards. A good friend of mine uses the crap ones and says "I've never had a problem with them." to which I always mentally add: "Yet".

I like your reinforcing structure. Those look like 15MM tubes, which I have a bundle of, so I particularly like that. I might add some deck tubes a bit longer than the tracks, but I really don't know if it's necessary. You could feed the structure from the deck side and then glue the tracks to the tubes at the same time you set them. You can notch the vertical tubes to join them to deck tubes with a holesaw the diameter of the tubes. I have a tubing notcher for building roll cages, but you can eyeball them with just a drill press and a vise pretty well.

I think if I did this I'd route the installation holes for the 45-degree braces full depth and then backfill with two-part foam, which is nearly as strong as PVC and is closed-cell. Or just ditch the 45 degree braces which means you could install the structure with just simple holes and a bit of gorilla glue. Incidentally, Gorilla Glue is like welding on carbon tubes. I'm not sure why, but you'll break the tubes before you break the bond.

[Surfside]

Thanks for the reply. Well, I was thinking of back filling also like you're suggesting.
I did not know GG was that tuff with carbon tubes. I'll have to use it...thanks
The tubes have a 27mm internal diameter, exterior is 30mm with a wall thickness of 1.5mm. Instead of adding a center post I thought the truss would add more strength, but it does create a little more work.

[clay]

I did a similar tube support in 2 boards, I wrapped in cloth to give more purchase

[daswusup]

Not chinook but a prefab cassette from Greenlight. I added 4 wooden dowels through cassette up to deck and put 2 birch ply stringers on sides. Probably not the lightest but I built this board out of shit lying around in my shop. Only for dw and light wind winging.

[blackeye]

I like the idea of the short dual stringers and also tying in the deck to the bottom. The tubes and dowels are cool, but I think a flat U shaped channel made out of HD foam and carbon would be simpler to make and install. The length should probably be something like @dawwusup shows and make the height meet the deck.

Cut two slots in the shaping foam to install. Make a recess for the bottom plate.

Add a top plate to tie the two stringers together, forming a box overall.

Could radius the top and bottom outboard edges of the slots so that some of the cloth transitions to the deck and bottom respectively. Fill these small voids then laminate the whole board.



As we make this area stronger and stronger, something else will fail. Some boats have appendages that kick up if striking something. It is held in place by a "fuse" - a planned weak/failure point. The fuse is replaced, or even better, reset (a "breaker") and onwards you go. Ski bindings are a good comparison. Snap it back into place and continue the session.

[PonoBill]

It's fine that something else fails; just try not to make that easy by not introducing stress risers in critical places. An ultralight downwind board should be downright flimsy everywhere but where you stand and where the foils lift--which is, fortunately, the same general area. If you're clumsy and heavy like I am that's a recipe for disaster, but if you take care of your boards the unstressed area to the front and rear of the standing area should be as light as you can make it.

I ran into Dave Kalama at the beach recently and we were talking about his board designs. I confessed that I had Mark Raaphorst build me a Kalama-style board, which I'm fairly certain didn't bother him at all. When I was admiring one of his recent builds, he said, "These are probably not the best for you, Bill; we both know how hard you are on boards". Damn. And then the conversation pivoted to what a careless klutz I am. I guess I'm at least famous for one thing.

[Beasho]

Is this a FLAT Edge, Flange?

I just bought these boxes encased in Divinycell and want to butt arrows up to the outside edge.  I just want to make sure a 1/4" Arrow shaft will sit flush against this rail.

[Surfside]

Is this a FLAT Edge, Flange?

I just bought these boxes encased in Divinycell and want to butt arrows up to the outside edge.  I just want to make sure a 1/4" Arrow shaft will sit flush against this rail.

Yes, they are flat.

[seastudent]

I like the idea of the short dual stringers and also tying in the deck to the bottom. The tubes and dowels are cool, but I think a flat U shaped channel made out of HD foam and carbon would be simpler to make and install. The length should probably be something like @dawwusup shows and make the height meet the deck.

Cut two slots in the shaping foam to install. Make a recess for the bottom plate.

Add a top plate to tie the two stringers together, forming a box overall.

Could radius the top and bottom outboard edges of the slots so that some of the cloth transitions to the deck and bottom respectively. Fill these small voids then laminate the whole board.



As we make this area stronger and stronger, something else will fail. Some boats have appendages that kick up if striking something. It is held in place by a "fuse" - a planned weak/failure point. The fuse is replaced, or even better, reset (a "breaker") and onwards you go. Ski bindings are a good comparison. Snap it back into place and continue the session.

I was thinking about that too. A readily available and cheap resource by me is broken hockey sticks. Nice light strong carbon rectangles. Take a grinder to an edge and pop in a box. I haven't done it yet but it could work. Maybe/

[Califoilia]

We been attaching the boxes to full thickness stringers for years now, and haven't had a single problem of an sorts.


On the last two DW boards (using 15" boxes instead of the 9" ones in the picture above), we've gone to cutting out four triangles in the stringers to make a truss like piece to reduce weight and - fingers-crossed - haven't had a problem yet with those either.

[jondrums]

A readily available and cheap resource by me is broken hockey sticks. Nice light strong carbon rectangles. Take a grinder to an edge and pop in a box. I haven't done it yet but it could work. Maybe/

A homebuilt wing-board showed up at the launch not too long ago and I got to chatting with the builder.  He used carbon hockey sticks FOR THE FOIL BOXES.  Not to support them.  He cut to length, used a router to cut a slot in the wide edge, closed out the ends with 3D printed glued in plug, and installed it into the blank.   It looked perfectly fine, I'm guess there were many layers of carbon patch on top of the box, but I didn't ask about the layup schedule.

[Dwight (DW)]

I noticed one big brand switched from stringers, with box set on flange, like above, to the huge block of divinycell.

I noticed another big brand switched from the huge block of divinycell, to the stringers with box set on flange.

This flip flop from two major players says to me, they both had failures.