I got this broken nolimitz v2 mast from someone who use a front wing over the recommended wing span during a bigger swell day. It cracked right at where the metal adapter ends. My original plan was just to cut a way the broken part and epoxy the metal adapter back on and keep it as spare mast if I ever switch to Lift foil. Quick and easy repair. But after a bit of think, why not design an cedrus adapter that will fit into the nolimitz. I already using there original mast and have their adapters. I thought about converting to the newer cedrus evo adapter with two pins but that would require me to buy new adapters. So end up sticking with the original cedrus.
Cutting out the damaged area is pretty easy with a small diamond cut wheel using a dremel.
You can see the holes where they inject the epoxy resin. Also you can barely see it is a dynemma cord that is tie to from this metal adapter and it runs all the way through the mast and assuming its attach to the base plate. I guess there were incident with V1 mast where the metal adapter came loose and the whole foil detach from the mast.
Took a while to figure a easy way to clean up the cured epoxy on the adapter. End up using a wire brush on drill and i clean up in no time. At that time, I was still planning to epoxy back the original adapter back on. You can also see the hole where the dynemma cord attach.
I took the measure from the original adapter and using Fusion360 to design the adapter. I also contacted Cedrus on their adapter dimensions but they didn’t want endorse my crazy idea which I understand.
Test fit with a 3d print part first before sending it to cnc shop. Which turn out I did made a mistake on my measurement.
Getting it CNC alu part locally is pretty hard. I email a bunch of people and most just ignored my request. Only one person reply back and shortly stop replying back. Probably due to my lack of knowledge in CNC design and one off part.
End up going through Xometry for the CNC. They instantly quote me a price. It crazy how many options on metal or 3d print metal part and surface finishes. I pick the CNC 6061 alu since its the cheapest. 3d print or CNC titanium would be cool too but it very expensive.
The part arrived couple weeks later but both of the 8m helicoil insert were damaged. Good thing Xometry quickly fixed the issue and mail me another part.
I guess you already glued it in place. I need to warn you that aluminum and carbon fiber don’t get along due to galvanic corrosion. You may have an issue. Typically you would need a layer of fiberglass in between the carbon and the aluminum. It can be super light fiberglass scrim but glass is non-conductive and forms a barrier. If you wrap the outside with carbon, put a layer of glass on first. But already you may have a problem due to the way you glued the aluminum directly into the carbon of the mast.
Thanks for the tip. Since the aluminum adapter is a bit smaller than the carbon mast, the epoxy layer will provide insulation. It’s also how nolimitz originally using only structure epoxy without fiberglass. I did add silica sand on the narrow flange area where the aluminum and carbon butt against each other. The silica sand will provide small amount of clearance so the aluminum won’t directly seat on the carbon. I got this idea from a company selling similar product.
I’m using regular surfboard epoxy for bonding the adapter back into mast. I already filed some groves on the top part of aluminum adapter and it was sand blasted. Which should give it a strong mechanic bond when I wrap 4-6 layer of plain weave carbon and compress it with carbon tow. Pretty much using what I currently have at home.
I don’t think it get loose with both internal bond and external wraps.
I think but am not 100% sure that the original design works because of the anodize coating on the aluminum, which is galvanically isolating.
An adhesive gap works in theory, but in practice it is impossible to truly “float” the part so the gap is consistent. Realistically, a corner will touch and that’s all it takes.
Just making the comment for future learning. Perhaps this project will all work out fine, I don’t want to be a nay-sayer, that’s not the point.
Totally understand, in case someone try to do similar thing. Also as you can see from the first post they only anodized the exposed area. They must machine the shallow cuts later. From what I read, anodized aluminum doesn’t bond well with epoxy and maybe the reason they chose to do this way.
Getting ready to lay down the fiberglass and carbon. I then wrap it with carbon tow to compress everything. I don’t have any pic of the processsince my hands were covered in epoxy.
I use it with my code 1250r for a week already. it feels about the same as my aluminum cedrus but maybe a bit flexy on torsion side. Maybe it’s more noticeable with this wide wing span but hard to said. I don’t notice the weight when I’m on foil but definitely feel the difference when carrying back to my car.
which I understand.
