Mounting NNN BC Bindings

[GrimSurfer]

Perhaps the trick is to pre-screw the binding. This will establish a thread pattern in the binding material.

Then back off the screws a bit, press the binding onto the ski by hand (after a bowl of Wheaties), and snug the screws down. Once it’s been established that everything is nice and flush, back the screws out of the ski, pop some glue in the holes, and torque it down for real.

I don't think this helps and is overly complicated.
Again, the problem is the engagement between the screw and the plastic in the binding.
Establishing threads in the plastic does nothing to offset this.

Either the binding needs to be firmly pressed onto the ski the whole time the screw is installed and tightened, or;
The screw needs to be turned in the binding until it is free to rotate BEFORE the binding is mounted to the ski.

The first way ATTACHES the binding to the ski.
The second way CLAMPS the binding to the ski.

Both are acceptable.
I prefer CLAMPED, as are all other ski bindings attached to skis.

I’ll bet you’re a scream at cocktail parties.

[Stephen]

Post removed for clarity.

[GrimSurfer]

Let's not complicate this.

Let’s not.

If you don’t know what you’re doing you can mess up a lot of things. So better to be exploit and help prevent somebody making a mistake.

Do you mean let's not, not complicate this -- a double negative?

Why complicate it?
It's pretty simple.
There's now two pages of on and on about this and less chance someone who is mounting an NNN BC binding for the first time will be able to make any sense out of this...

I’ll bet you’re a scream at cocktail parties.

Oh, that almost hurt...

The first statement was made in overt agreement. But it was sarcastic.

Moving on…

The Rottefella mounting instructions say nothing about clamping or pressing. Still, we know that some kind of pressure works best when mounting a binding. It can be done through the fastener/driver interface, through the binding, or both.

The fasteners apply force to the binding through a plate. That makes good engineering sense.

Thinking that the fastener provides any clamping power through the plastic bottom doesn’t make any good engineering sense. Fasteners provide clamping power by tension. Full stop.

The only advantage one may get from having some interaction between the fastener and bottom of the binding is lateral location. This is called “single shear” in the engineering world. Any sane mechanical, structural, or aerospace engineer will point out, however, that single shear fastening is THE WORST way to maintain tension. Why? Because such an orientation leads to stresses in two planes — vertical and horizontal.

You don’t need threads if the purpose is lateral location. All you need is a reasonably snug fit. Threads in that area of the fastener just lead to problems… like jacking during installation.

So why does Rottefella use a fully threaded fastener? Who knows. I would posit that it is efficient to use common fasteners across multiple product lines. One also saves money using a simple screw instead of a more complex one. And nothing contributes to the bottom line like simple and cheap. So I’m going for profit as being the practical reason for the arrangement.

This doesn’t matter much at the shop level. If it doesn’t fit, bang it into place. If it isn’t tight, torque the nuts off of it. A sporting goods store isn’t the clean room at NASA but that doesn’t mean that we can’t aspire to do better.

So now I’ve covered fasteners. Let’s move to clamping.

What type of clamp are you suggesting. Probably something like soft jaw Irwin hand clamps. Sure, those can work. But there isn’t a practical way to clamp near the front of the binding. Not a flat surface in sight.

But if you can make that work, then I’d support it 100% because I’m all about effect. So my mind remains open to clamping.

As for establishing threads in the plastic… yeah it does help. It stabilizes the faster and minimizes the risk of jacking. It’s done all the time in wood working (the better way to prevent this is pre drilling the binding, but you wouldn’t like that either)

When you ended a post with “Thoughts?”, I took that literally. I’m a literal guy. Next time use “Applause” if you want blind agreement instead of, well, thoughts.

[Stephen]

Post removed for clarity.

[GrimSurfer]

...
Let’s move to clamping.

What type of clamp are you suggesting. Probably something like soft jaw Irwin hand clamps. Sure, those can work. But there isn’t a practical way to clamp near the front of the binding. Not a flat surface in sight.
...

Would you please show me were I suggested clamping the binding to the ski during installation?

You said “firmly pressed”.

Any thoughts on screw types, force vectors, etc.? (Not looking for applause but, rather, something that makes sense with regard to screwing and jacking in the plastic on the underside of the binding… because that’s what is causing most of the problems for people here.)

[Stephen]

Post removed for clarity.

[GrimSurfer]

I must say that I have never had any issue mounting NNNBC bindings tightly to the ski- as long as I am paying attention and applying enough downward pressure.
I mount them entirely by hand- driving the screws with the appropriate pozi-drive.

I haven’t had any problem either but accept that some people have. I can also see the design issues that might lead to problems though.

I guess that’s where we differ.

[Stephen]

Post removed for clarity.

[GrimSurfer]

I haven’t had any problem either but accept that some people have.

I guess that’s where we differ.

And now we come full circle.
Some people either have enough experience working with things to recognize a problem before making a mistake mounting the binding, or, they have already made the mistake, and know what to look for.

I wrote the original post to try and help those in the first group.
If I offered bad, or incomplete advice to that group of people (not the group who already know, and for which my post would be unnecessary), then please, anyone add concise, accurate, simple additions.
As it is, I think what I posted in the original post is sufficient, but if not, I have no emotional investment on improving it.
I would just like to not COMPLICATE matters...

How does that make sense? I mean explaining things to people who have enough experience to recognize a problem before making a mistake. All logic suggests they don’t need the help. Or am I missing something in your statement?

I see good value in doing the most practical good — helping a skier who is likely to make a mistake with a new set of planks. Likely a first timer.

You might be confusing complicating things and truly understanding them.

[Stephen]

Post removed for clarity.