Bic HiFly Universal Joint broken - how do I fix it?

[dave.rugh]

Thanks for all the responses, yes making an insert threaded to attach a modern joint seems like a great idea. Wouldn't be difficult to machine an aluminum rod in the shop and tap it; but I'm not sure about the different methods to connect it to the board (epoxy, silicon). Maybe some kind of fiberglass sleeve around the aluminum rod would adhere to the board better.

I don't think the existing locking mechanism is reliable; my brother said it pulled loose when he was sailing it, so that would tend to rule out machining off the end of that piece and putting a threaded insert in that. Unless there was a way to rehab the locking mechanism.

Is this the kind of base I'd want embedded in the board?

Chinook Rubber Universal Joint




What kind of joint would that be connecting to? What brands/models do you suggest?

Will I be able to connect it to my existing mast or do I need to make an adapter for that end also?

Thanks again, much help

Dave

[swchandler]

The following link will depict a number of universal options you can choose between. The general style you would want would have a threaded rod coming out of the base of the universal to mate with threaded female receptacle or rod. Both tendon or hourglass designs are viable, with the former being arguably better, and a bit more expensive. Whether you pick a Euro-pin or US cup connection at the top depends on the mast extension type you have or want.


http://www.chinooksailing.com/products/index.php?cPath=2


In addition to the Chinook brand, you can also go with the Streamlined brand. Both are leaders in market for quality universals and other windsurfing components.

[Sailboarder]

The link below is for a Europin single-bolt with a tendon. This is what I use. There is another standard for the attachment part: US-cup. And there are 3 types of universal joint. The one you showed is called hourglass, the one I use is tendon, and mechanical is also available. I prefer tendon over hourglass because it's easier to inspect to change it before it breaks. The choice of what you use is not critical, and can be debated to death. You could go with what you find easier in your local used market.

http://www.chinooksailing.com/products/product_info.php?products_id=110

If you enlarge the image, you will see the screw at the bottom. You need to screw this in your board until tight. In modern boards, a square nut is used in a track, this allows for some pre-ride adjustments. You just tighten in where you want in the track.

And below is a good quality europin adjustable extension. It is made to fit standard diameter masts (SDM). The inner diameter of the mast must be somewhere between 48 and 60 mm.

http://www.chinooksailing.com/products/product_info.php?cPath=5_38_41_44&products_id=130

If you are investing in the future, you could buy such an extension.

However, there are also fixed 0 cm plastic 'extensions' that are inexpensive. I got used ones for free and paid one 10$. They are typically Europin however... They are easy to modify to accomodate a slightly smaller diameter or any larger if required.

Hope this helps!

[dllee]

Just use a piece of rope like I suggested, end of problem, go windsurfing.

[joethewindsufa]

[dllee]

An idiot would use a length of rope around 10 feet long, and tie the knots at each end.
An idiot would use a fishing line, around 80 lbs.
An idiot would use twine, so it unravels in water when wet.
Which are you again?

[dllee]

Now, a true McGiver would use a piece of rope, tie knots adjoining each other between the base parts, and tie knots at each end on the other side of each parts to hold everything together.
A super genius McGiver would pull all the parts tightly together.

[bred2shred]

You need to come up with a method of attaching a single bolt style mast foot to the board. Check out the chinook web site as suggested above. The mast foot will come assembled with three main components - a plastic base plate, a rubber hour glass, and a plastic cup on top. You will also need a mast base extension. This is the part that inserts into the bottom of your mast. The extension has pulleys and a cleat built in so you can downhaul your sail. The base extensions also allows for length adjustment and come in various lengths. The bottom of the base extension engages the cup on the top of the mast foot and this connection is what connects the rig to the board and allows for quick disconnect of the board and rig.

The base plate on the mast foot has a threaded stud that sticks out of the bottom about 1 inch. It is 8mm or 5/16, somewhere in that neighborhood and it comes supplied with a brass T-nut. Typically this T-nut engages the mast track on the board and allows the mast foot to be secured firmly to the board. What you need to do is build an insert that can be dropped into the mast base hole in your board and will accept the threaded stud on the bottom of the mast foot. Then you can use a modern mast foot and base extension on your old board. If this is an old polyethylene board then you're going to have a difficult time grtting any adhesive to bond to it. Epoxy won't and silicone is way too weak for a mast base connection. Maybe 3M 5200 would work. I think you should definitely try to get some type of mechanical connection in addition to adhesive.

sm

[dllee]

Use the rope.
Chance are, it's BicDufourWing, a nice beginner board for most everyone and a great light wind lake board, with a semi displacement semi round hull, square tail, and a red stripe around the outside.
It's made of brown polyurethane foam, so most epoxys will adhere.

[Sailboarder]

I think the idea is to reuse the existing hole, not to drill a new one. I assume the hole is 10 to 15 cm long. If the OP uses a tight fitting rod of the same length, he will have a large bonding area. He could add ribs both on the pin and the hole to help to increase grip

Because of the geometry, the forces on the adhesive will only be shearing forces. This means no-concentrations of forces on a weak spot. An analogy would be to try to separate 2 plates glued together. You are allowed to pull only from the center of the plates, not from the edges. This is quite strong.

I'm not a mech engineer, but I designed small opto-mechanical parts in the past. I compared a few times epoxy with silicone for shock resistance. Silicone was always better when attaching 2 surfaces together. It has to do with the fact that epoxy is more fragile than silicone even if the epoxy has much more tensile strenght and adherence probably too. (Fragile means that a crack will propagate in it. Glass is very fragile, but has more tensile strength than steel. In real life, it breaks easier!)

I would try silicone myself for sure, and I had previously thought of all this in case anything happen with the current mast foot of my old board. I would glue it and pull with all my might on the pin to make sure it stays. If it stays, I would then make a new leash to secure the rig on the board in case of deconnexion. All old boards have provisions for this. Mine has a track that goes up to the tip of the board, will little cracks made to secure the shock cord in place along the way.

Anyway, many solutions will work, I'm eager to learn what the OP will eventually do and how well it works. Let us know!