Gatormodded Powershell V2.0

[gator1]

Here are @OB's powershells with V2.0 gatormod.

 

The challenge I'm facing with modding the powershells is the flexible plate. It allows the back foot to lift off the ski as the plate bends in between front heel and rear toe. So, in an OTF crusher, front foot can stay planted even as the Velcro peels off under the back foot. This makes it more likely that all the weight will get transferred onto the front foot and then overflex the front ankle. POP goes the AT. Or SNAP go the ankle bones.

 

But, people love the fact that the plate flexes (to a certain extent) with the ski. So, I need to let the plate flex along with the ski, but then get stiff as hell once it flexes beyond what the ski will do.

 

My first try had rails along both sides of the plate. They allowed flex, but were too big and close to the edge of the ski.

 

V2.0 has telescoping graphite rods between front and rear towers. As long as the plate is flexing along with the ski, the rods just slide within each other. But, if @OB goes OTF, the cord attached to his front knee will pivot that lever at the rear, (with all the holes in it) and pry most of the rear half of the plate off the ski. As the rear heel lifts, the tops of the front and rear towers get much closer together. The telescoping rods run out of travel, the towers can get no closer together, and the plate becomes, in effect, an aluminum and graphite I-beam. If he keeps going OTF, the cord can then peel the complete, now stiff (albeit with a bit of a smile in it) plate off the ski. NO POP.

 

This is also interesting since if it works, we can run any boots on a flexible Velcro plate. And, we don't need to be as precise about how much Velcro we use, since we're using displacement of the front knee rather than lifting force at the heel to drive the release.

 

To set the allowable flex, I put the plate on my poor busted Prophecy, (how much better would Howley have looked in the picture with a nice orange '13 that matched his t-shirt?) propped it on two blocks of wood at tip and tail, and jumped up and down on it as hard as I could. Kept shortening the rods until they didn't touch no matter how hard I jumped.

 

Yes, those graphite shafts are indeed hunting arrows.

 

No, I didn't drill lightening holes. @Horton assures us weight is not an issue, and this mod hasn't added much to begin with. I'm actually in @eleeski camp on binding weight, but I have a rule that correlates machine tools I use with how much of the six pack I've drunk. By 5 into it, I've worked my way down from mills and grinding wheels to only drill presses, and somewhere between 5 and 6 only allen wrenches remain on the approved list. So, at the point it was time to drill the lightening holes, drill presses were off limits.

 

Yes, I know there are easier ways to integrate the towers. I didn't think of that till I was almost done.

 

 

[ral]

Lightening holes look cool, though...

[mwetskier]

looks like a lot of seriously dangerous metal parts to collide with if you accidentally interact with the ski at all during a violent fall.

[ral]

I see the back part of the system as potentially dangerous. That part can for sure get in contact with some back body parts...

[Than_Bogan]

Fascinating stuff as usual. I am so happy people are continuing how to explore reducing one the most common season-ending injuries in our sport! My uneducated questions:

 

- Are two rods needed? Or is that mostly to keep the weight symmetric?

- Could the rod(s) be attached to boots on both ends? That might significantly reduce the total amount of "extra stuff."

- Combining both of those, a single rod from font of rear boot to rear of front boot would be cool, but I can't figure out how the skier would actually get into the rear boot with that!

[klindy]

I haven't tested it but I'm not sure you need any of that stuff. With a pry bar you can separate literally the back couple inches from the ski and the rest of the assembly peels off like a banana. If it works the same with your feet on the ski then none of that stuff is required. Can you just add enough of a lever to peel up 2-3" of the plate from the rear?

 

I suppose a "crash test dummy" way to test the theory would be to put a dowl or something else to prevent the back 2-3" of velcro from engaging and go out and try an nice slow speed turn with a lot of pressure on the ski tip (standard Powershells not something with the gator mod). Of remove one side of the last 2-3" of velcro and give it a test.

 

I'd bet if you get barely enough disengaged it will work. I'm not convinced you can keep the plate on the ski unless it's fully engaged from end to end. In fact, I believe the flexibilty of the plate actually helps the whole thing disengage. I'm on Powershells and have peeled off enough times to have some experience with them.

[gator1]

@ral: its a prototype. Having said that, the lever with the hole drilled in it flops around when not on the ski. Other than that, the added inch of the two rails off the back side would really need one hell of a scorpion fall to run into anything. Not much longer than the plate on my stealths.

 

The towers are tucked up against the boots.

 

@than_bogan:

-Two rods to keep the plate from twisting as it tries to bend.

-I wanted to attach the rods to the ankle pivot points on both boots. Too much modification to the boots required (they are @OBs, and I'm trying to get proof of concept without trashing his boots)

-Agree. I spent a couple of days trying to figure that out. Then I realized the plate is so wimpy that I needed to beef up between the rear of the plate and under the heel of the rear boot so I quit trying. The best I came up with was some type of snap in gizmo that allowed the rod to pivot up out of the way while the skier is putting the boots on.

 

The whole back end is pretty crude, but, can be made a lot more elegant if I start integrating the boots into the load bearing structure.

[ral]

@gator1, was thinking getting into the butt (no pun or joke intended) on a not so radical fall, but could be upper on a more extreme one. I guess that just putting some padding on it or making a flat back piece joining the two rails would lower the risk damage. What I do not like is to have parts that can dig in/concentrate a big load on a small surface.

[gator1]

@klindy: you are probably right. In fact, I'm sure you are right in most otf's. I started down this whole path with just exactly what you describe, and it does work like you said: once you start the peel it kind of just keeps going. And, adding the mod in that design would improve your chances considerably.

 

My concern is the one-in-a-thousand fall. The one where you are perfectly balanced over your front foot, with all of your weight plus 5Gs of deceleration smashing you down over that front foot, and no pull coming from your FF heel or back foot to continue the "peel". In that fall, you need the gatormod cord from your knee to act as your adjunct AT, and PRY the damn plate up off the ski. Which it can't do if the plate just bends.

 

And, its that one-in-a-thousand fall that gets us. I've been skiing 40 yrs (wait, that can't possibly be true). Probably more than a thousand falls. But I didn't get hurt until 3 yrs ago. And it was a perfect, in line smash down on top of the ski fall that did it.

 

That's my big beef with every binding out there. That fall is a common denominator with most of the guys who get their ankle injured. Until somebody can describe to me, in good solid mechanical terms that take into account the physics that fall, how any of the bindings on the market today (or proposed for that matter) will save you in that fall, I'm not done drinking and hacking down in the machine shop.

[gator1]

@Ral, yep, more blunt edges are easily integrated once/if we ever get to where OB wants to use this for real.

[mwetskier]

@OB -ive had yard sales where i collided with every part of me against every part of a ski imaginable from a bone bruise on my hip to slashed ear and temple. if youve never hit the ski or had it hit you in a fall then you havent taken enough falls yet.

[mwetskier]

@gator1 -why not have two pairs of gator mod levers one set at the back as usual and one shorter set at the mid point of the plate? you tether the two levers on each side together and articulate them with graphite rods so tripping the back levers with the pull cord trips the middle ones with the graphite rods at about the same time. that puts every thing lower to the ski and eliminates the tall up rights that could be just waiting to carve out a kidney.

[teammalibu]

Looks like a lethal weapon!!

[ForrestGump]

What you don't know is if there will be a different 1 in a million situation with the gatormod.

[gator1]

@shaneH Maybe you meant it, or maybe just choice of words: I don't know. But if I can better the odds from 1 in 1000 to 1 in 1,000,000, then I'd be nuts not to do it.

 

And that's been my guide post with this. Everything I do, at least to the best of my ability, makes the binding to which I've attached my mod release at least as well as it did before I modded it.

 

I can't see not trying to fix something that we KNOW IS BROKE, just because it might not fix it all the way.

 

Its a fast, violent sport with lots of momentum and torque. We're going to get hurt. But, if we can avoid one major cause of an injury that is hard to recover from and at minimum loses you a season, why not try?

[ForrestGump]

I didn't mean what I said with animosity or anything. Just that in risk management you find that there is always some risk, either positive or negative. And sometimes creating a solution to one risk, creates another risk.

[gator1]

No animosity perceived. And I get the rule of unintended consequences. That's why the marines make test pilots. @OB rocks!

[gator1]

@ral, I just noticed the picture doesn't show the axle which ties the two bars together at the rear. It does a pretty good job of acting like the plate you suggested across the back of those two bars.

[eleeski]

@gator1‌ Hunting arrows? Really? Brilliant! Cheaper and easier than Boron? Another thing to try. Thanks (I think) for creativity that makes us all think.

 

Eric

[gator1]

Well, hell. I just shoved this in the box to ship to OB, and I realized that those back two uprights don't even need to be solids. If I run an oblique from the axle up to a pin joint where the push rod currently connects to the upright, and run a cable up from the bottom of the upright to the pin joint, it'll accomplish the same thing. Damn, @than_bogan and @eleeski, you are supposed to catch this stuff.

 

Same thing will work for the front uprights. What a doofus. Prof. MacKenzie is spinning in his grave and I've let the U of I down. Again.

[Sethro]

Just what I was thinking, "why on earth would he make those back two uprights solids?" Just kidding, I get confused just looking at that. I need you to engineer a new dock system I have in mind for the fluctuating Rock River.

 

I'm still waiting for my special Glock magazine you invented.

[gator1]

Hell. I forgot. Did you want the easy load version or the empty mag indicator?

 

I sold the patent on the floating lift thing, but I got another version I've been thinking about that would double as a dock. Or what're you thinking of?

[Sethro]

I sent you a message so I wouldn't mess up your gatormod thread any worse than I already did.

[gator1]

Yep. But getting more civilized. Stay tuned for video of v3.0. I don't get the issue with the string, but that's normal for me: blind to aesthetics. What bugs you about it?

[gator1]

Need the lever to pry the plate loose. String is at about 35 degrees to plate, so without lever it is mainly pulling plate frontwards, not up.

 

If most your weight is on your front foot, as it was in your fall, the string will move the lever, the lever will pop the tail of the plate off, the string and your back foot will lift the rear of the plate, BUT THE FRONT FOOT WILL STAY PLANTED. Because the plate will just bend between your feet. So I need to selectively stiffen the plate during a release.

 

I hope to post videos Monday. Or if you want them now just PM me. I can't get the damn things to load so I'm gonna get my IT guy at work to help.

[gator1]

The point is that in your type of fall it would not matter if the plate had NO dualoc. Your weight is centered over your front heel, and is being driven down violently by momentum. Your foot is planted by force, not by dualoc.

[Wayne]

Some amateur feedback for your next design. Would it be possible to have a single "rod" or flat plate that uses the same concept that allows the boats to flex to a point then when it hits the single "rod" the plate can no longer flex because it is trying to compress a solid column. I was thinking something along the lines of boots that are spaced above the plate slightly. Trapped underneath a 1+ inch wide aluminum plate with a couple of end stops. The trapped plate may rattle around until the powershell plate flexes enough to hit the stop.

 

Packaging everything under the boots would take away the fears of people coming into contact with something as the outward appearance wouldn't change much.

 

Your latest design and I forget which ski it was but there were recent pictures on this site where the space under the bindings was "hollow" got me to thinking "what a good spot to package some sort or release mechanism". I keep thinking the future of safe release systems will be something magnetic. Embed some super magnet pucks in the ski and boot bottom with a small indexing plate just to ensure your bindings are in the right spot. Then to adjust the release you add or remove magnetic pucks from the bindings.

 

[gregy]

@scotchipman‌ from some previous discussion it looks like the pure crushing injuries are far more common than I would have thought. The string going to the knee is really the genius of gator's release. It takes the extreme force at the ankle (and lower leg) in a crushing fall and transfers it to the knee which then causes a release.

 

Understanding crushing OTF http://www.ballofspray.com/forum#/discussion/comment/166052

http://www.ballofspray.com/forum#/discussion/comment/165582

 

@wayne when I read your idea a cable system under the plate came to mind. So that when plate flexed it tighten a cable (or cables) that ran from toe of front to heal of back.

 

 

[gator1]

guys, thanks for the input. There is another thread in the last month or so about a big, strong teenager who had @scotchipman‌ fall and injury, but on EXOs. He actually BENT the bar that runs under the boots, by his rear foot lifting, releasing the rear foot, but the front foot was planted so hard the bar bent rather than let his front heel come off the ski.

 

So, that's my proof of concept.

 

There are lots of ways to do what you suggest @Wayne‌, and its a good idea. I'm trying to retrofit, though, rather than full redesign.

 

@scotchipman‌ I'll make you the rear portion of the @ob's system if you want to test it that way. It'll definitely be better than what you have.

[Wayne]

@gator1‌ a retro fit might be possible but I'm not too familiar with powershells and how they mount to their plates. I'm thinking aluminum spacers that raise the bindings off the plate to create enough space for a piece of flat bar stock (say 1/8th inch thick and an inch or so wide). The spacers could be designed to create a captive channel for side to side and the bindings and binding plate would box everything in. Then you would have to drill the powershell plate for a couple stops at the front and back.

 

You need to make sure the stop bar doesn't get any bending forces applied otherwise it's purpose is compromised. I think your design is more robust for a retrofit. What I'm thinking would take some playing with the math to make sure everything has clearance to function properly but I think it is possible to make it a retrofit. I just have a feeling it will have increased stiffness if not done right.

 

I still want to develop magnetically releasing bindings. It would be pretty cool to have no screws, inserts or Velcro around your bindings. The only issue is you might get pulled underwater to a course anchor if you needed a ton of magnets.