Cost reduced...cheap and dirty... CPP unit

[thudpucker]

31970
Three moving parts. It dont get much simpler than that.:D

This is my quickie, one lunch period, one KFC Thigh, two Napkin, Controllable Pitch Prop drive unit.
It came out in Landscape so you'll have to print it out in landscape and then look it over.
You'll see that all the parts can just about be made in a Barn with saw's, a Welder (Maybe) and some Drills n' Taps.

I didn't spend any time with the shifting shaft connection to the slider because it can be done a number of methods.
The slider just sits in place. The Drive shaft rotates under the shifting slider.
I believe a Sleeve of the same stuff that's inside the Cutlass Bearings can be used to make the slider.

As the driven hub rotates with the shaft, the inner shifting studs of the prop blades rides in the slot of the Shifting slider.
If wear is going to be a problem, that raceway in the shifting slider is where its gonna be. So the Cutlass bearing stuff will probably be the answer.
Who the hell knows? Its just an idea. A good Mecnanical Engineer would consult with a Chemical Engineer to find the right metals so no one Metal would wear any faster than the other.

I think the blades can be 1/4" Aluminum. The Hubs of the blades can also be Aluminum. Something like 4130 etc.
Just blocks cut with a hacksaw, and drilled and tapped to stay together.
Cheap, quick and on the boat for Beta Testing.

I dont seem to be able to get rid of the bad Thumbnail at the bottom. I need help when it comes to stuff like this.

[marshmat]

Nice and simple, just as anything on a boat ought to be.

With the shaft rotating inside a non-rotating slider sleeve, wear in that raceway could be a problem. Not just on the raceway itself, but also on the studs projecting from the blade hubs- they'd tend to get flat spots in the positions used most often. Just thinking here... but if it were possible to key the slider ring and drive shaft together so they both rotate, then the wear problem here is gone. You'd then have to control a rotating slider ring, instead of a fixed one, but since there has to be a fixed/spinning interface somewhere, it'd probably be easier to manage inside the boat (or at least not in the prop hub itself).

Of course, there will be the usual problem of sealing against water ingress with concentric shafts if you were to do that.

I think it's a good concept (I love it when normally pricey stuff gets done on the cheap). A bit more refinement is of course necessary, but it's a start :)

[thudpucker]

Good observation on that slider problem.
I considered that about the time I got down to the end of the Meat on the KFC Thigh.
What' s gonna wear more? What would be the cheapest and easiest to replace?

I decided the larger surface which should hold more Water as it rotated, with less of a tendency to twist or distort would be the thin area between the slider and the shaft.

The Studs I envisioned would be Aluminum and the slider would probably be aluminum. They could both be Stainless as well.
That gaping slot would have lots of water and the chances of the bearing contact surface between the stud and the slider would stay cool pretty well.
There's a problem for an R&D lab eh?

The Studs could be a Stainless Screw, tapped into the Hub of the prop blade.
The Slider could be a series of Spacers and washers held together by Cap screws as well. This thing is envisiond to be made in a Barn by some Guy like me.

The Prop Blade SHAFT could be an Aluminum Dowell. About 5/8 or 3/4 inch in diameter and two or three inches long.
There'd be little wear on it. Just thrust and Torsion. The Hub would be another Aluminum spacer. The two held together by a Cap Screw.

The more HP you put on the shaft, the better some of this stuff would have to be. If the operator will stay with something small like a 5 Hp B&S it should work well just as depicted.


A slot cut in the Prop Blade SHAFT would hold the actual Prop blade. The Blade would be some 1/4" Aluminum. Cap Screws through the Shaft and the Blade will hold the Blade in place.

Part 'A' and 'C', the Driver and Driven parts are Aluminum. The A is a flat piece with some holes drilled in it. 'C' is a piece of Aluminum Pipe, also with holes drilled and tapped.

You saw the two Lock Inserts 'B' are just the pieces cut out after the hole for the shaft of the Prop was drilled. That must have a Hole drilled and tapped for a Cap screw to hold it in place after the assembly.

All that stuff can be purchased from local hardware. You may have to order some of it but its all available from suppliers.

If the slider was captivated by the studs inside the blades the wear problem would be eliminated with the 'difficult to make' parts.
That would leave the only wearing part's at the junction of the shifting shaft and the sliding part.

If I made an 'end piece' to the shifting shaft that would loosly fit into a slot in the Slider, we'd lose the precision of the Controllable Pitch.

There's always forces at work, pushing against something. Wear is going to be a problem.
We are in "these days..." as the old folks say, of astounding Chemicals and I'm gonna assume there is a Chemical out there somewhere that will be a good water-lubed, wear resistant, combination of thrust bearing and shifting device.

So far as this drawing and Idea goes, its a gift from me (the Idea guy who came up with it) and anybody who can make it work well enough to market it.

[TollyWally]

LOL,
A good idea doesn't care who has it. I'm going to have to print your drawings as I can't really make out the details on screen.

Thanks ever so much for sharing your ideas. From little acorns sometimes mighty oaks grow.

[FAST FRED]

"This is my quickie, one lunch period, one KFC Thigh, two Napkin, Controllable Pitch Prop drive unit."

Great , If I treat you to an entire PAIL of chicken could you post the drawings for

1 a battery with 100X the power density of a lead acid wet cell.

2 an anti-gravity device

3 a perpetual motion machine , of only 3 moving parts.

FF

[mydauphin]

Can I have an apple pie with that?

[thudpucker]

The next step is to make the Shaft/Prop/Rudder assembly Dissapear.
Lifting up into a box. And of course the Hydrogen Generator must fit in there somewhere. Also a folding Solar panel to keep the Batteries up....

By the time all this inventing to make a small boat a nice cheap thing to own, it's gonna need a bigger boat to carry it all around.

[kistinie]

There's always forces at work, pushing against something. Wear is going to be a problem.


it may not be a problem if the parts that wear are inexpensive and easy to change.

The application is for light leisure boat, not used a lot, not for many hours, and inspected every 6 month or year for anode change and cleaning at least.

[FAST FRED]

"The application is for light leisure boat, not used a lot, not for many hours, and inspected every 6 month or year for anode change and cleaning at least."

Sounds like the perfect requirement for an outboard.

FF

[kistinie]

Yes it can
CPP replacement by outboard is already effective
But it is not the subject studied

[thudpucker]

If you turn a Mechanical engineer loose on this thing, and he consults with the Chemical engineer, you'll have the answers to the two major questions in a few days.
Horsepower and wear!
Kistinie you asked for a Cheap one, and you said America was a Dead place to look, so I drew this up in one lunch period just for you.
You could have done the same.
What happend to your inventive spirit. So far all I've seen from you is the Complaining spirit.

[marshmat]

A few more thoughts:

- Aluminum for sliding surfaces and highly loaded parts- I'm not such a fan of that idea. I suspect aluminum would wear quickly and be prone to galling in this type of application. For surfaces that wear, a hardened surface would likely be preferable. Aluminum's easy to machine, but may not be ideal for this case.

- Lubrication- Whatever they make those cutless bearings out of seems to work with water lubrication, but that's an exceedingly simple assembly where some wear is acceptable. In our "hillbilly CPP", sloppiness and wear will be problems, and if we want it to last, our bearing systems would have to be built to fairly high precision- and be able to hold that precision. Maybe slider cars in that raceway, to carry the prop blade studs, would be an improvement over bare studs sliding in the raceway? That might provide enough contact area for a water-lubed raceway to work...

- A 5hp B&S has been mentioned- that may not be a big engine, but for small components close to the shaft there's still an awful lot of torque to deal with. Designing to handle the engine torque isn't enough- we'd have to account for the much larger, momentary loads that would occur if we hit a log or rock. In such a situation, I'd much rather limp home with a bent blade than row home with a torn-up hub.

[thudpucker]

The "Slider cars" is a great idea.:idea: If the Cars were made of the Phenolic stuff and the "Walls" or "Borders" the Cars slid against were a Polished Stainless Steel washer, the 'Hi wear' might be minimized. Good idea.
Keeping the heat down at the contact area is the key. If the water can cool that small spot adequetly or if the 'spot' can be made large enough to dissipate the heat with some water flow, we've beaten the problem.

That still keeps this "hillbilly:p CPP" down in the 'user manufacturer' class.

So the trail of Rotational Stress; From the Rotating shaft, to the Hub and its grip on the shaft, to the Driven hub, through the Axles of the blades.


Then the stress from the blades trying to twist the Axles, back to the studs in the inside of the Prop hubs.

These studs are trying to force the slider "D" in one direction or the other.
That's another reason why I let the slider 'float' over the shaft.:)
The slider will have two opposing forces, and hopefully that will nutralize over the length of the slider. If the slider is long enough, so much water will be forced under it to sufficeintly keep it from 'grounding' at the front or back.

Also if a guy were crafty enough, he could cut a Curved or Radial raceway inside the slider that would help carry fresh water supply along the inside of the slider to help with the Lube and cooling.

:D I'm getting kinda excited about this thing now. I'm hoping sombody will build it and let us see if it's a worthwhile Idea.
Also, I believe there were at least 30 Patents applied for on this issue in the early part of the last century. We need a volunteer to look that stuff up.
There may be the "right answer" out there that's been lost in time.:(

[kistinie]

Kistinie you asked for a Cheap one, and you said America was a Dead place to look, so I drew this up in one lunch period just for you.
You could have done the same.
What happend to your inventive spirit. So far all I've seen from you is the Complaining spirit.

You are not fair !
i bring a lot of informations and do a lot of work to find solutions for many things.
I do not think America is a dead place as you have kept a pioneer spirit as well as many other quality we do not have in Europe, and specially in France.
I just said i do not like patent.
I do not complain, i shoot :D
If i just help a little, its just that i am not able to, not enough experience and knowledge on CPP:(
Thanks for this great and courageous enterprise
Do you think this could lead to a product ?

And now, APEX our Troll with one more constructive intervention

[apex1]

Yes it can
CPP replacement by outboard is already effective



Who has told you that nonsense?



its just that i am not able to, not enough experience and knowledge on CPP:(


First proper statement after 268 posts!

[robert allen]

gooday my name is robert allen from australia i am only new to this but i may be able to save some people out there a bit of time i have been working on a small propulsion unit for some time now it might be of some interest and a short cut for some specially the canoes & kayakers and others it can be seen on my website www.whippella.com.au .This unit is st/steel

[thudpucker]

Robert that looks like a prop or something adapted to what we call a Weed-eater motor.

I couldnt see how it works. Is it a Controllable pitch Prop unit?
Can you reverse the prop? While its in motion?
C'mon back and explain how it works.