The Couple Across the Dock from Me Invented Something Pretty Cool ...

[avb3]

Originally Posted by Nicholson58

Seaduction, If you really want that jointed shaft on the cheap, take an automobile transaxle half-shaft and modify for your use. We build dynamometers for drive trian subassemblies. A typical trans-axle has a universal (Cardan) joint on the outboard end and a CV joint on the inboard end. They are made to run in salt spray. A good machine shop can make adapters for you. The tech issue you need to address is that you will need a GOOD combination radial and thrust bearing to support the prop shaft designed to fit your vessel since this shaft can ONLY transmit torque and absolutely zero thrust.

Am I missing something?

The only thing the shaft can produce is torque, a rotational force. Only the propeller can produce thrust. As such, I don't understand your last sentence.

[savoir]

You could get the same cresult by tying a bowline in the outer end of the mooring line and dropping it over the cleat as you pass. If the rope is soft and the loop collapses, tie the bowline through some plastic tube in order to hold the loop open.

[Therapy]

Originally Posted by Seaduction

I think the idea shows great "outside the box" thinking. I hope somebody comes up with the idea of "universal joints" for boat drive shafts just like automobiles have. That would take care of all the boatcrobatics involved with aligning the engine and shaft. I've rarely had to replace a U-joint in my vehicles. (hey, I'd like 1% of the profits here).

From seeing that connection on the first "real" boat I was on in the late 70s I always wondered the same thing.

[cat man do]

Originally Posted by savoir

You could get the same cresult by tying a bowline in the outer end of the mooring line and dropping it over the cleat as you pass. If the rope is soft and the loop collapses, tie the bowline through some plastic tube in order to hold the loop open.

Or if on a dedicated mooring line with sliced loop, why couldn't a piece of s/s or monel wire be pushed into the entire loop.?
Strong enough to hold the loop open, weak enough to straighten under load

[DeepFrz]

Aquadrive
Just one of the many...

[goboatingnow]

Originally Posted by Seaduction

I think the idea shows great "outside the box" thinking. I hope somebody comes up with the idea of "universal joints" for boat drive shafts just like automobiles have. That would take care of all the boatcrobatics involved with aligning the engine and shaft. I've rarely had to replace a U-joint in my vehicles. (hey, I'd like 1% of the profits here).

Halyard have had them for years ( aqua drives) CV joints for boats

[Bash]

Originally Posted by David M

Clever idea, but all he has to do is to slow down and he would not need it.

I've been told the same thing about....

Oops.

Nevermind.

[Nicholson58]

That thing sort of reminds me of this game - can't remember the name. Something about some kind of toss. something to do with anatomy.

[S/V Alchemy]

Originally Posted by Seaduction

I think the idea shows great "outside the box" thinking. I hope somebody comes up with the idea of "universal joints" for boat drive shafts just like automobiles have. That would take care of all the boatcrobatics involved with aligning the engine and shaft. I've rarely had to replace a U-joint in my vehicles. (hey, I'd like 1% of the profits here).

But they have:



http://www.aquadrive.net/how-it-works.html

[S/V Alchemy]

Originally Posted by Ozbullwinkle

Alchemy - I think it is a cool & simple solution for docks with cleats when one is on a high sided vessel , is shorthanded and especially when there is a crosswind blowing across the berth.

Yes, I was thinking that. Not for everyone, but for some, a useful tool. Like circlips pliers or a two-jointed rachet wrench adapter...you use 'em twice a year, but you REALLY need them when you do.

[senormechanico]

Originally Posted by avb3

Am I missing something?

The only thing the shaft can produce is torque, a rotational force. Only the propeller can produce thrust. As such, I don't understand your last sentence.

Axle shafts transmit torque to the wheels.
The suspension takes all the sideways forces such as cornering etc.
The axle shafts have splines to absorb suspension movements.

On a boat, the torque from the engine is transmitted to the prop.
The prop's thrust is transmitted back up the shaft and in most installations, is actually PUSHING the engine and transmission forward which drags the boat along with it via the engine mounts.

[avb3]

Originally Posted by senormechanico

Axle shafts transmit torque to the wheels.
The suspension takes all the sideways forces such as cornering etc.
The axle shafts have splines to absorb suspension movements.

On a boat, the torque from the engine is transmitted to the prop.
The prop's thrust is transmitted back up the shaft and in most installations, is actually PUSHING the engine and transmission forward which drags the boat along with it via the engine mounts.

Gotcha, now why didn't I think of that! Duh!!!

[David_Old_Jersey]

Nice idea .

Probably works quite well on own dock (with cleat in the right place), but not so sure about in other places......personally I would have gone for a simple loop (inside a piece of hosepipe) on a stick / tube....available soon at USD41 .

[Noname]

Originally Posted by DeepFrz

Aquadrive
Just one of the many...

DANG!! Too late again!

[denverd0n]

Interesting idea, and kudos to them for being able to make and market this product.

Still, I have to agree with the person who said they wouldn't need it if they weren't coming into the dock way too fast (at least in that video).