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?

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.

@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?

@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.

@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.

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.

Sent my 5 yr old hybrid drysuit back to O'Neil. Its had a rough life, including working on boat lifts, installing and pulling courses, working on boats, etc. Told my dealer to spend no more than $100 refurbing it.

Came back with a new zipper, new collar, new wrist gaskets, taped and glued leg seams.

NO CHARGE! That's pretty damn cool.

Slow ski means lift/drag is lower. That means you are pushing the ski farther ahead of you to stay balanced. At higher speeds this effect is magnified.

Let up at the edge change, the balance point moves from farther back to neutral. Bigger weight shift required.

Since your subconscious rides the back foot too much, climbing onto the center of the ski is tough for you to begin with. Add a draggy ski you have to push ahead of you and you are too far back to make the trip.

Also, draggy ski suffers more deceleration when you hit wake, so you have to ride it farther back

So, in your "all other things being equal" post you are talking about skier A and skier B riding the same ski, at the center line, with the same acceleration, with the ski at the same angle to the center line,but at 5 mph different velocity? If so, then:

As other nerds have stated, centripetal load on the line must be greater.

wind drag, not inconsequential, increases with square of velocity, so to maintain 5 mph advantage rope load must be greater.

water drag, even less inconsequential, increases with square of velocity, so rope load is greater.

All heading in wrong direction to your hypothesis, based on what you feel.

My vote is that the key variable is acceleration. And your hypothetical situation does not match what you are feeling.

@dusty: The drag down/overshoot happens 6 times during a pass. Maybe 6.5 times depending on if you are late to 6 ball and have to grunt for the exit gates.

You can run the boat 46 mph past a set of guide balls, then slow it down at a steady rate to 26 mph as you pass the next set and get a perfect time.

Its what the boat speed is doing on an instantaneous basis throughout the pass that creates the feel, and advantage for a big guy if the instantaneous speed is varying more in his favor.

Hand drive somebody through the course, and have somebody watch ZO digital speed (Does ZO let you do that, ah, I guess if you set it for 36 and pull 34 it does). Drive by the tach, gassing it when they pull and backing off when they don't to hold RPM (@AB's hot stick method). If you are good, you can get a perfect time. Congratulations. You are a PP.

But even with a perfect time, the instantaneous speed as reported by ZO will vary A LOT with every pull and preturn. And if you use the same method with a big strong guy vs a small weak guy of roughly the same ability you will see that the peak vs minimum speed difference is a lot larger with the big guy.

@dusty: Yep, you are exactly right. The best drivers could hold RPM constant (hot stick as @AB calls it) once they determined what rpm they needed to get the airguide centered up, based on that boat load, prop, skier weight, headwind, etc. PP classic was a look-up table driven, high update rate version of the human driver.

But at a steady rpm, the big guys pull the boat down more than small guys due to prop slippage under load. And, as @AB says, a sudden change in one of the parameters (him hammering it) made the prop slip more, which threw the drivers fuzzy logic control loop out the window and resulted in a much greater deviation in speed during hammer time.

With a no-lag speedometer, his spatial knowledge of when the pull was going to come, and familiarity with the boat and skier, the best driver could hold SPEED almost constant, given a strong engine at sea level and a semi monster or less at the end of the rope. Airguide made a no-lag speedo for awhile (my patent). Anybody who got pulled constant speed hated it. It meant a lot more throttle movement (and more for a big guy than small), and a lot "harder" "no mercy" pull. It took about two passes off your PB.

@bruce_butterfield: Depends how you define "max performance". If you define it as a 36mph pull, +/- 0.10 mph, a good manual driver cannot get close to consistently maintaining that pull.

If you want to define "max performance" as "how many buoys can I get around with the boat speeding up and slowing down while averaging 36 mph", then a hand drive will provide it. Just as a dream weave will get you a lot more "max performance" than a straight line pull down the center.

I'm pretty clear on how a closed loop feedback system works. With a high enough sampling rate, and sufficient response speed and power, the set point can be maintained to a point that the difference in speed is not perceptible.

Hell, my system, in 1986, was close to your diesel tugboat. EVERYBODY hated it. Just taking the airguide lag out of the system, taking the human response time out of the system, and cranking the sampling rate up got me close to a tugboat. But that took about TWO passes off everybody's PB. O'scope traces showed I was damn close to 36 at all times.

I quit because I didn't want to fight the battle presented by admitting all scores prior to speed control needed an asterisk.

The dirty secret (which drove all the development time invested), is that PP and ZO coupled with a 350 hp motor and FI are perfectly capable of providing your tugboat pull. It'll knock about two passes off yours and everybody else's PB. Ready? Lets do it!

So, the industry spent years trying to create a system that will protect our egos with A1+ to C3-, which is actually just letting you induce some error between set point and actual speed at different, consistent points in the pass (instead of where Jack Walker's need to take a piss and a break caused him to miss set point).

We've now boiled the frog to the point that the big guys don't have an advantage. We have the tech now to crank the damn thing up, and run everybody at set point. Take all this BS about ZO A+ setting out of the discussion. But we'd all have to face a big decrease in our "max performance". I'm in big favor of doing that, since longer line lengths minimize the effects of dream weaves.

But, right now, I'm just a drunk, old, bald engineer, so I'm happy enough to be able to compete with a 6'2" 220 pounder on close to equal terms.

@andjules: Yep, that was what I was trying to say: My theory is that you are no longer required to be NFL linebacker to be a worldbeater slalom dude or dudette.

Doesn't mean you CAN'T be a worldbeater if you are a NFL linebacker.

I'm not prepared to say those of slender build are now at an advantage. But I think strength to weight ratio, at a given level of skill, is now the main predictor.

Been thinking about this for awhile, and the questions on 5.7 vs 6.2 needed to pull the big guys triggered the geeky again: When I was testing speed control back in the 80's, I had an o'scope on my electro speedo, recording the actual, no-lag reported speed (airguides had over a 0.5 second lag) as the top drivers in the world hand drove guys on the pro tour.

The monsters, like BL, experienced much larger variations in speed than the smaller guys. They all got good times, but the heavier you were, the more the drag down and overshoot.

In essence, the big guys were skiing "PP", while the small, lighter guys were skiing first generation ZO.

Two causes: hand driving was limited to "no gassing" because the response time of humans and airguide made it impractical, AND, the engines just didn't have the torque to hold speed.

Another interesting point (well, to me anyway) was that the big jumpers weren't getting 35 mph from the turn to the wakes. No matter how hard the driver hammered the throttle, they drug the boat down to below 33 in the most extreme cases, while Sammy and Geoff were seeing close to 35.

So, I think ZO and 350 hp + motors enabled Nate's dominance, and made it possible for Regina to whup most of the big dogs.

And this is to take nothing away from BL and any of the other stars of the past, they were studs of no small order. But, I think its interesting that tech MAY have altered the prototypical body type required to dominate the sport.

@MrB I believe the place in Denver is called Regenex.

I have chodromalacia (sp?) in my back leg knee. Which means cartilage on back side of knee cap is flaking off, has craters in it, and chunks stuck to the bearing surface. Tried PRP on it two months ago, no joy.

My knee surgeon is also my ski buddy, so we're going to try scoping it first to take out the mechanical chunks, then, while he's in there, a stem injection. This knee started to go bad playing soccer in college ('82). Along with my head starting to go bald. I thought they'd have this shit figured out by now.

It was a partial failure. In a hard turn at short line the flow is wrapping around the bevels and sticking to the rails, creating lots of drag at 35 on up.

Version 2.0 should fix that.

On the other hand, it looks like I didn't affect the flex on his new N1, and the new single line knee harness also looks like it will work.

Main reason for this post is to thank @OB for his efforts and willingness to strap an untested device on his feet and go skiing. He's THE MAN.

We're doing this long distance, so the effort he's putting in and the unknowns he is facing are considerable. THANKS @OB.