
Originally Posted by
CascadeCmpnts
There were a LOT of things considered when making these. All those factors were balanced out as best as possible and that's what made the design what it is. As with anything, the best balance is going to be different for everyone. Since this isn't intended to big some big product line it's just a matter of whether or not the balance you want aligns with ours. If not that's fine, we won't fault you.
What it needed to solve was:
- Post alignment being super sensitive (I've mounted the same posts and screws multiple times in the same hole and had the alignment be different every time)
- Screws and posts loosening while skinning up and to the right while on edge with fat skis (yes I know this is very specific, but that's a daily thing for me). Pretty much your weight trying to twist your heel off the downhill side of the skis acts like a mini ratchet on the posts.
The things that needed to be balanced were:
- Weight
- Strength
- Stiffness
- Cost/complexity/time
- Ease of installation
- Stack height
There were a good handful of different paths that were considered. This included the design as is, screws through posts that are part of the base plate, screws through stainless posts that key into the base plate, having the whole thing made out of stainless, making it out of titanium, and making new toe pieces so that the posts could be entirely different.
Making new toe pieces:
Pretty much threw this out right away because it would consume a ton of time and the only benefit would be freeing the design from an existing mounting pattern. There might be some post configuration out there that is better and has a unique mounting pattern, but there also might not be. Doesn't seem worth the time and cost.
Making the whole thing out stainless or titanium:
HEAVY. Durability would be fantastic and it would solve everything at the expense of weight and time/cost. These are materials that are very slow to machine and not cheap either. So it would weight a lot and cost a lot/take me a lot of time to make. It's a touring set up so the main thing is it can't be that heavy.
Screws through posts that key into plate:
This was the number two solution in my head. Durability is good and weight is only marginally more. The downside is what it would cost since it's more complex. Price is largely driven off of machine time, part count, unique part count, and material cost. This would have a total of five three unique parts and nine parts total. On top of that stainless is slow to machine. The amount of time required to clear the material from around the posts in the single piece aluminum part is actually really small. The most time consuming thing by far is the pockets, but for weight to us that's worth it. Making posts out of steel would be more total machine time because the posts would take a fair bit longer to machine. On top of that the part count is almost doubled and there's a whole other unique part. Then there's the screw thing... I'll elaborate on that later. Long story short, I like the durability due to not having to worry about stainless posts wearing, but the time that would have to go into making it brings it down a step.
Screws through posts that are part of the plate:
The only thing that would necessarily be different about this compared to the current design is the position and size of the screws. As you all are aware, the mounting pattern would be exactly the same. The drawback is longer screws weigh more and aren't as stiff. For us the mounting pattern isn't a very big benefit. Keep in mind options where the mounting pattern wasn't even a standard pattern were considered. Having the mount be a stiff as possible outweighed the mounting pattern especially when you throw in the fact that it would be heavier. I know it would only be a handful of grams heavier, but the scale is already tipped. Now I know the plate underneath could get thinner, but I'll get into why that's not happening later.
Current design:
Short, stiff, screws and low weight, plus the strength is there. Where this lacks compared to the number two design is the posts are aluminum. There isn't really any slop in the interface and the leading cause of wear is usually impact related due to slop. The fact that this is lighter and simpler than the keyed in stainless post design tips things in its favor.
Now about stack height. With the plate thickness as is, the ramp angle is zero. There's nothing wrong with a level binding necessarily. No matter what the stack height at the toe is going with any of the designs. I believe a 2mm difference is something that is only noticeable on paper. I've skied a lot of bindings with different ramp angles and honestly never thought much of it. But let's say that 2mm is a number worth chasing. You then have to ask yourself, what do you have to give up for it? This brings us to stiffness of a plate.
The stiffness of a plate is proportional to the height cubed. Pockets don't have a big impact on stiffness because they are located in areas that load doesn't really go through so if you lose the pockets you don't really gain stiffness. So forgetting about those, how does the stiffness of a 5mm plate compare to a 3mm plate? The 5mm plate is 4.63 times stiffer. Yeah 463%. Not making that up you can do the math yourself if you want (5^3)/(3^3) is 4.63. Stiffness of the plate is huge when it comes to isolating the runout of the posts from any screw misalignment. Drill jigs are good, but they aren't perfect so this helps keep any screw misalignment from affecting the posts.
Now about the stiffness of a screw. The stiffness of a fastener is inversely proportional to the length of fastener that isn't threaded. The short screws are about 91.5% stiffer than the long screws through the posts and the thin steel plate. The short screws are about 200% stiffer than the screws would be in the number two design idea. Because of the stiffness thing, longer screws only feel worth it if they are to allow you to attach a more durable post to the plate. Four new holes in your ski won't affect things as much as the screw stiffness. I've skied some seriously swiss cheesed stuff and the first thing that failed were the bases and edges from tons of use, not the mount.
So there you go. If you need a different balance of things then us, I would say read through all the reasoning and use it to guide your own endeavors. Anyone who wants can go and make their own plates and we won't feel put off by it. But there isn't some disconnect because we only design a part or only use it or any of that. We do the design, programming, machining, and then actually use everything. So the design isn't disconnected from reality, it just might not be the same as your reality. This is exactly the same is with the bike links. Not everyone's trail is the same so there's never a one size fits all.
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