Mounting screw length

I am thinking about making an adapter plate for my tele bindings on my BD's and was wondering if there is a rule for the screw length. If my ski is Xmm deep without the original plate and the adapter is Ymm high, what length should the screws be so that they neither dimple the base nor pull out on the first turn? Is there just one length for all skis and so I need to make my adapter a certain thinkness? (I already did a quick search on binding screws and know the standard but my question did not really get answered).

The bindings are mounted to the plate with cap screws so that is not an issue at all, it is the plate to the ski that is the issue.

Thaks y'all

Are you not just mimicing the mounting of the current plate and then just able to re use the screws. Rule of thumb on bindings is 7.9mm for mounting plate and 8.1mm for no internal mounting plate. Gets murkier with the Atomic plates. Maybe Mtnlion has some of the generic plates and can measure screws if any come with those.

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Originally Posted by L7

Maybe Mtnlion has some of the generic plates

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What are the odds?

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Originally Posted by cantunamunch

What are the odds?

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Without looking at that list I figured the odds to be better than fair to middling. At quick look at the list and eureka (I was just there too).

What bindings are you mounting? I went around in circles on this one. First I built a mounting plate, then ordered the mount anywhere plate from Mtnlion (did not end up drilling them), and now have bombers drilled directly into the ski. The G3 pattern hits the ski right next to the indention (center channel) and allows the screws to pretty much sit in all glass and very little foam. I did not have a problem last year with this set up and I'm about 190lbs in my birthday suit. This method will be a good deal lighter, and if you build your own plates you will most likely stiffen up the ski a bit unless you have a separate plates for the front and back of the binder.

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Originally Posted by Oarhead

I am thinking about making an adapter plate for my tele bindings on my BD's and was wondering if there is a rule for the screw length. If my ski is Xmm deep without the original plate and the adapter is Ymm high, what length should the screws be so that they neither dimple the base nor pull out on the first turn? Is there just one length for all skis and so I need to make my adapter a certain thinkness? (I already did a quick search on binding screws and know the standard but my question did not really get answered).

The bindings are mounted to the plate with cap screws so that is not an issue at all, it is the plate to the ski that is the issue.

Thaks y'all

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I really have no idea but to me it would make sense to just add the depth of the adapter plate to the lenght of the original screw to get a proper screw length to hold the plate firm.

so original screw length + plate depth = new screw length?

I am mounting bishop bombers to the big daddy's and the problem with mounting straight to the ski is that the heelpeice has 2 screws that mount in the 'cleavage' between the beta channels. I don't thtink that there is enough material to screw into that could stand up to my weight and the forces that I would put on it (6'6", 210 nekkid, big feet = big levers and moment forces).

The plate that I ripped apart is the 'mount anything' plate from mtnlion. I was looking at the other plate and it looks a bit warped so I am afraid that it will follow the original in a spectacular manner of destruction. I just don't trust the aftermarket plates enough hence the aluminum riser from the machine shop route.

I am not going to use the original holes as they are too far forwad for the tele mounting pattern. I will jsut plug them and mout my own plate; the original holes are about 5cm forward of and 1/2cm behind the pin line.

The one thing I was not sure about was whether there is a universal length, divisions (ie 5mm increments), or any (ie 1mm increments) length could be found for the mounting screws. If the screw are in any lenght at all, then are there any issues with using longer ones?

I will post pics once I get a camera available.

Time for T-nuts mebbe?

Amazingly enough the ski itself is not damaged at all, it was just the plate that ripped apart. I don't want to take an essentially brand new pair of skis (3 or 4 days only) and start hacking them apart to place T-nuts), I would rather find an easier route.

Once you've threaded past the top sheet/torsion box and into the foam, what does extra plate screw length buy ya?

^^^
If I make this riser, the length of the screw needed will be different to what is currently in the ski. I am trying to find out what increments the screw lengths come in so that i can design the correct thickness of the riser plate. All of this may be a moot point now that Kneedropper says it can be done.

Here is a pic of what I did:
http://www.biglines.com/photos/normal/biglines_45170.

Measure riser plate, measure thickness of ski at mount point, subtract or account for any plate countersink, determine how deep you want to drill and what screws you'll use. Then, if you have screws too long, run the points on a belt sander to shorten them up to the desired length.
What kind of threads on the scews do you plan to use for this?

I didn't know that there were different threads for mounting, I thought they were all self-tapping Posidrive ANSI#12 spec.

How deep can you drill into the ski? ie is there a max depth or minimum amount of material below the screw to not have dimpling?

Thanks for the advice already given, that will help.

I'm no shop tech, but I imagine on a 12mm core you can go 8-9 mm.
Dimples typically occur when the screw either pushes out the base because it's too long or the hole wasn't drilled deep enough and the screw pushes material into the base as it cinches itself down. I've seen some tele guys seek use wood threads, as opposed to the machine threads most binder screws come with, for more bite into wood cores that aren't sandwiched between metal. But you have to make sure the head on the screw fits into any countersink in the plate or binding. If you use your best judgement on the depth and diameter of the holes and line up the appropriate length screws, you should be fine as long as you get good bite on the threads. The guy to ask is Idris. He knows everything pertinent to your question.

edit: if you don't have a bit that will stop at the desired depth, wrap some tape around it so it does stop.

General rule of thumb is 8mm of screw into the ski. Skis with metal should be tapped ( I don't think this applies to the atomics, but not sure) Tapping will help tremendously (30% stronger hold than untapped) with screw retention. Like Vin said, plate thickness plus original screw length with give you your new screw length. Make sure to countersink for the screw in the plate depending on angle of the head.