It would be very interesting to see if the pucks can take the frequent loads from riding. I see a potential watchout where the engagement flanges step down to the main body of the pucks. The 90° angle there is an area of stress concentration. The best thing to do would be to transition the flanges down to the surface of the puck by adding some material to form a radius or fillet. The same goes for the underside of the puck where it meets the flanges. I imagine that if it can fail, that will be the spot. However, I’m not familiar with the material properties of carbon. If its strong enough it may not ever be an issue.
The cutouts were not cut in a sharp angle, but have a small radius because that is an area where it could fail. The pucks are also bolted down off course, and they don’t really bend either.
I’m not that worried about the underside of the puck where it meets the flanges. It seems pretty strong, but we won’t find out untill we ride it hard for some time.
If I would have made the pucks out of solid steel, would you think that is strong enough? Good carbon fibre is very strong. A lot of people think it is like aluminium, but it’s not. It’s actualy stiffer AND stronger than steel. It’s just not very good at handling impacts, like hitting it with a hammer or something but I don’t see that happening when it’s locked into place and my foot is on it..
Been a while since the last update. The bad news is that I still didn’t get my pins for the LT brackets, so I couldn’t get the touring mode done before my trip. I ordered them from http://www.splitboards.eu but after months of waiting and sending mails they finally let me know they won’t be getting the pins untill next season. This sucks.
I’m now thinking of not bothering to get the pins at all and build a system similar to the new Sparks that have a fixed pin in the brackets.
But I did finish everything else and took my board on trip. We chased the snow for 4 days in Switzerland and I think this was a really good test for the board in ride mode at least. I rode everything from pow to ice, and only used the splitboard.
Nothing broke, the carbon interface is easily strong enough. The board still feels light, and I don’t notice any difference at all as a result of splitting it. I expected it to be less stiff and not hold an edge on ice or carve as well as before, but I don’t notice it at all. This is a board i’ve been riding for 2 seasons, so I know what it felt like before splitting.
It did feel a little slower on flats, probably because of the epoxied t-nuts and the cut in the middle. But I was still faster than my buddies on Salomon sickstick’s, probably because I wax my board very well before every trip.
The bindings are very stiff and responsive and are positively stuck solid to the baord by the pucks/disks, no flex there at all. They felt more responsive than my Cartels.
I should have some pictures of the trip next week.
I’ve thought about it, but since i’m in Europe there isn’t much point in shipping pucks to splitboarders in the US. It will be too expensive. But I would not mind if a lot of splitboarders could benefit from this, I still think this the cheapest lightweight solution.
My idea was to give the CAD drawings to Rughty, so he can have some sets made. This makes more sense to me because he already has a neat solution for mounting the bindings to the touring bracket. He’s also much better at machining stuff in general. We also compared some prices for waterjet cutting and that seems a lot cheaper in the USA as well.
Finally had a little time to work on the binding again yesterday. I started making the parts that will hold the binding to the touring bracket. This is 250g/m2 uni carbon in two layers pressed without vacuum, so it’s not strong enough to bear loads. I just wanted to get all the dimentions and angles right first.
These parts will go into the vacuumbag later where I will bond the binding to it with additional layers of carbon. But putting the whole pin and brackets into the vacuumbag was not an option, the forces of the vacuum would force it out of alignment so I wanted to get this sorted first.
I made a mould out of plexiglass that has the same shape as the binding baseplate, and waxed it with mould release. You can see I used the brass bushings theat normally go into a Spark binding, the carbon will go around that. Thanks Jeff from Spark for sending me these! The “pin” I used is a fibreglass rod from a kite, real pins are not available right now in Europe.
The whole thing clamped in place. It has peelply on both sides so additional layes will stick. The yellow is just cloth to soak up extra resin.
put extra layers of carbon around the metal insert and all the way to the first screw. also make the holes further away from each other if the binding base allows. Mine broke on the last trip and it’s because of the the 2 holes being so close. My binding base had 4 connected holes and I made an extra one. on the left side there was little space for a 4 mm hole so that’s where the touring bracket broke. I also thought putting the 3 screws in a line would not be good somehow. but now I’m thinking about making the bracket longer like yours and have the third hole done behind the original holes. Your base might be different though! How will Mr Chomps connect to the board?
That’s a good point, but my binding has even less material in the toe area than yours. So I didn’t plan on any screws in the baseplate at all as it’s not possible.
The RX has a removable toeramp, if you take that off there is not enough room to even consider two or three bolts.
It will be bonded to the binding, and the carbon will follow the binding in an L shape at the sides of the foot just like the binding. Vacuumpressing will pull the carbon in the cutouts that are in the binding and the screw that mounts the toestrap will secure it in place even more.
But it’s good to see the force that is put on the whole thing is enough to break such a part. I will make the carbon thicker and a bit longer underfoot to be sure.
since u can play around with the carbon why not try to rebuild the toe ramp with the metal inserts inside. smth like this: You can put small pieces of polystyrene where u need to create space between carbon. This will create a strong structure while keeping the whole thing light I’m not sure how well the carbon sticks to the aluminum but i would rather put at least 2 more screws in there somewhere and make it removable. Keep in mind that if any of these parts fail you might be somewhere far away in really deep powder and not be able to get out. mine broke just half an hour into the trip and what should have been a max 4 hour fun tour turned out to be an 6 and a half hour struggle with the snow. 😥
I thought I post this because it shows some vacuumbag stuff, and in case anybody ever needs to make a carbon part. Small parts are tricky to get right, but hopefully this will be good when it gets out of the vacuumbag.
Here’s the two parts I made earlier with the Spark brass inserts to minimize wear. I glued a small carbon strip on it to get the angles right, and left the pin in. The “pin” is a rod from a kite, that was the only material I could get in the correct size here, I will make pins from aluminium with the help of a friend lathe later.
Cleaned and scuffed the binding and made some kerfs so it bonds better.
During layup, triax carbon folded under and over the binding and around the pin. Another layer will cover the top. You can see it goes up to the sides of the binding as well, so I can screw it to the sides with the screw that holds the strap normally. No extra screws planned, lightweight.
The pin stays in there during curing to keep it straight.
The vacuumbag still open on one side. You always want a much larger bag than the part or it will pull folds everywhere and twist the part.
Vacuumpump turned on. You can see the epoxy bleed into the cloth, the vacuum presses all the extra resin out to make it strong and light. I use a claening cloth for this (yellow) but you can also use toilet paper 😆
The trick to vacuumbaggin is getting everything airtight. I used a suction pad from a satnav to fix the vacuum hose to the bag, you can buy special connectors for this but this works great. The pump turns on every half hour, my pump leaks a bit so I put a small valve in the hose to prevent the bag from losing vacuum.
Now I have to wait 8 hours and pray that the part turned out good.
It looks good from where I see it! In fact i don’t understand why big companies don’t make the whole base of the bindings out of carbon.
Did you put some layers under the base too? I see how this will secure the hole thing in place so no bolts needed. But if it’s too thick under the binding then it won’t spin on the pucks so well. Some stuff will actually be good there because the binding is a little loose in the toe area in riding mode! Did you try it on the Spark bracket? everything stayed in line?
Looking good… The only thing that jumps out at me is if there is enough clearance in the toe of the bindings to pivot freely in touring mode. Seems like the boot might hit the board a bit early, causing a little toe mashing. But, that could just be the angle of the photo.
All in all, I like it… Nice and light, and should be pretty strong… Hope you get to ride it before the snow is all gone! Would be a drag to have to wait until next season..
Those pucks are just great, logical and simple. One thing I think you could have done differently is the touring pin setup. If you made the toepiece longer, then you would not get the toe of the boot touching the board.
To stop the rotation of the binding in ride mode, you could use a carbon fiber stop on one side of the binding and a Karakoram clip on the other to hold it in place.