gatormodded powershell pics

[gator1]

Ready for the boots. Center cross piece has the bolts with slop to allow plate to flex limited amount. Slot in front of rails allows flex also. Hard bolted to plate through rear cross piece. Upright with cam follower pivots when front knee goes forward, pries, then pulls plate off ski. Plate flexes till hits end of center bolt slop.

[gator1]

That's the marine version. Air Force is quite a bit lighter.

[Horton]

I don't know if I should post a Panda or a "what you talking about Willis"?

[E_T]

@Horton neon hunt vest is required

[gator1]

@horton: Marine pilots think air force guys fly like wimps. Air force guys think the marines are heavy handed chumps. The mod came out a little beefy.

[skibug]

That is still one FUGLY vest! As far as the latest gatormod for the powershell plate...holy SH@#^$%$T! I applaud the efforts and innovation; but, that is quite the build out.

[gator1]

@skibug: I figure if I can sell them for about $3950 apiece I can break even. Soooo...maybe a little design for manufacturability is in order.

 

Weight isn't that bad. The one in the picture, when added to a standard powershell plate and boots, results in something that is still lighter than a stealth setup.

 

This one is going down south for testing, and since I'm not going to be with it as it gets put through its paces, I had to err on the side of bbbbbbeefy.

 

Of course, about 90% of the way through building this, I thought of a much simpler and lighter way to selectively stiffen the plate. I don't know why, but I can think and think about an invention, but until I go to the trouble of building at least one I don't hit on the optimal design. Just one of many failings, doesn't even make the wife's top ten list.

[jipster43]

I've heard that 70% of all innovation occurs through production. That looks like some serious Naval Architecture there!

[ral]

The more I see that vest, the less I like it.

 

It matches with the new Quest graphics, though... Mmmmmm...

[gator1]

@jipster, if I could get it down to 70% I'd be celebrating.

[jayski]

why would you want to 'stiffen' the plate to aid in release?

[ForrestGump]

@gator1 Have you flexed a ski bare and with a dual locked on plate? The ones we did a few years ago stiffened the center of the ski up a good bit. What about after your modification?

[Chef23]

I understand how the Gatormod works on a binding with a release but not sure how you arg going to pry a dual locked plate off the ski.

[gator1]

@shane: nope. Don't have a flex tester. That is some very interesting data though. Was the increased stiffness from a dual lock plate enough to be felt by a skier? Did you also test full plates mounted with slotted screw holes, and did they add more or less stiffness to the ski then dual locked?

 

My mod adds no stiffness to the plate until the mod has begun to rip the plate off the ski. Those rails float on the plate until the panic lever at the rear of the mod has been activated by the skiers front ankle beginning to over flex.

 

@jayski:

 

Suppose you have just stuffed the nose of your ski exiting 5 ball, and you are RFF. The ski has pivoted about 45 degrees around the nose, and is now travelling cross course, and slower, than your body, which is still travelling downcourse. Suppose it is a really bad day, and you happen to be perfectly aligned with your ski.

 

You are now being crushed, by your momentum, onto your front foot. You are not going OTF enough to create much lift on your back foot. So all you weight, plus the added force of momentum, is forcing your hips down and forward. Unless you are super strong, your right leg, hammy, and glutes can't overcome the force. Your right knee is now rapidly being forced to bend, moving in front of your right ankle. Your Achilles is stretched to the point it is beginning to feel pain. Since there is no lift from your rear foot, the plate is going to stay attached to the ski.

 

The bad day is going to come out ok, though because you are running a gatormod.

 

The string from your right knee has activated the panic lever at the back of your plate. Under the force of your knee, and with the mechanical advantage of the lever's rotation, the rear 5 inches or so of the Velcro is separated, and your rear heel starts to lift.

 

The fall continues, your right knee keeps moving ahead of your ankle, but, the string is now lifting the entire plate off the ski. Your right ankle, up to your right knee, through the string to the rear of the plate, through the floating rails that are now stiffening the plate, back to your right ankle, is now a solid mechanical triangle. Your ankle cannot be forced to flex anymore.

Your knee keeps going forward, the plate pivots up around your front toe, you roll off the ski, and life is pretty good.

 

If, however, the plate flexes between your front and rear boot, the string will keep lifting the rear heel of the back foot while the plate bends. The front heel will stay planted as your knee continues to move past your ankle, since there IS NO (or very little) LIFTING NET FORCE ON THE FRONT HEEL IN A CRUSHING OTF. Pop goes the Achilles.

 

This is why in the once-every-few-years-perfect-storm-crushing-OTF the plate needs to become stiff once we start to rip it off the ski to save the front foot.

 

 

[mwetskier]

couldnt your vertical stiffening ribs be composite so there stronger and lighter?

[gator1]

@ mwetskier. Yep. But I'm going to replace the rails with a suspension bridge approach that should weigh almost nothing. If it works. Still thinking on it.

[oldjeep]

Here is a silly question, but why not just use something like the heel piece from a snow ski binding? If the main release criteria is your rear heel pulling then it seems like the easy solution. Ski bindings have eliminated the flex deadspot for years by simply mounting the entire binding to a flexible track where only the toe is firmly anchored to the ski and the rest of the plate/boot is allowed to slide fore and aft on the track.

[gator1]

@chef23 I decreased the mech advantage of the panic lever by giving it more lift per degree of rotation. The Velcro come apart much more gradually than the pin release plates, but with about the same work required. The force to start to separate it at the rear is less, but we need to lift it farther with some mechanical advantage before we turn the lifting duties over to pure vertical vector from the string.

 

If the vertical component from the string is not enough to pull the plate, and the fall continues, the front knee gets in effect some help from the string. The knee stops moving ahead of ankle. If hips keep moving ahead knee must straighten since string won't let it bend further. As front leg goes straight, rear leg also goes straight. This converts the crushing fall into a peeling OTF. Which Velcro does a super job of dealing with all by itself.

 

Which is why to use gatormod both feet have to stay in the boots. If the rear foot comes out during any of this the fall won't convert from crushing to peeling.

 

I hope my terminology on crushing vs peeling is clear. Those are terms I coined as I went through the design process; if they are not self explanatory let me know.

[gator1]

@oldjeep that's the problem. In a crushing otf there is no heel lift. So the release criteria is not force at heel (with a gatormod). It is instead angle of front ankle flex, which translates to relative position of front knee to front ankle. Which translates to position of front knee relative to rear of plate. Which the mod converts from position to force to defeat the attachment mechanism.

 

Not a silly question. Nobody thought of moving from angle to position to force before, or were maybe stupi/crazy/desperate enough to try it

[oldjeep]

One more silly question then. So if the issue is front ankle flex, then why don't they just build the boots so that they won't flex? Again, back to the snow ski technology - there is no way that you are going to blow an Achilles in a ski boot.

[ral]

@Oldjeep, couple of things.

 

With enough force, the heel component of a snow binding will release, preventing a tibial/knee fracture. Not the case without the Gatormod in single plates.A person I know, though, blew both achilles on a really weird fall on a GS course...

 

Also, ankle flex is something you want when skiing.

 

 

 

 

[ForrestGump]

Yep, I know two people that have smoked their achilles in ski boots, one of which was in custom made carbon $2500 boots.

[oldjeep]

Wow, I'd sure like to know how that happens unless you are running around with your boots unbuckled and the bindings cranked to 20.