CPP desapear from recreational boats Who gets the benefit of the crime ?

[kistinie]

Not us, final users, for sure.


CPP = Change pitch propeller give your engine always the good torque to fit the one you need.
They also free you from the real pain in the ....to decide if pitch will be 8 or 12 or 7 or 9 or 10 ...or Grrrrrrrrrr !!!!

As my good friend APEX said "Put a CPP, your engine will last for ever"
And he is perfectly right as long as you are gentle with him when cold and give only good synthetic oil.

As a CPP rise your propulsion efficiency, so lower total needed energy for the same travel.

As i think it is the only solution for an efficient electric propulsion and regeneration

As the CPP where common item in the 50's and 60's

Since then only billionaires and big commercial boats have access to CPP



Don't you see something wrong ?
Does this two speed world looks like something you already know ?


CPP, industrially produced wouldn't cost arm and leg like today.

(French say for cost arm&leg, cost "la peau des fesses" or "la peau des couilles"), i let you translate by yourself.
(Swiss, " un saladier")
Canadian ?


So to sum up
Without CPP, your engine last far less and you use much more energy
Once again, market is not always right as we see it needs to be saved every ten years

All this sound like cell phone for 1€, then monthly 100€...


Do your share this point of view ?

If no explain why.
If yes,
How could we correct this problem ?
First step would be to identify existing manufacturers of CPP, proposing solution for small engines and at accessible prices

Merci !

[TeddyDiver]

real VPP (variable pitch propeller)
http://www.westmekan.com/index.php?o...d=12&Itemid=14
or cheaper solution
http://www.bruntons-propellers.com/A...toprophome.htm

[kistinie]

Thanks for theses:

Are there any manufacturers in the states for small CPP units ?

Have you an idea of the price of the smallest CPP from West Mekan ?
I guess it is the HV25 with manual oil pump ?

[TollyWally]

In my humble opinion CPP systems are filled with expensive machined parts made of expensive material. A shaft within a shaft, swiviling prop blades, and things I'm not even aware of. I would love a cpp system. I believe the lack of availability is due to the expense of manufacture.

[thudpucker]

That Auto-prop looks something like an old Centrifigal prop I saw on a sail boat.
Either direction it was spinning, the prop blades flew open and cut the water.
When the shaft was not spinning, the blades were free to flop down next to the shaft and virtually out of the water. No resistance at all when the shaft was not turning.

Is something like that still around?

[kistinie]

Yes you are right but it seems it is also the fast low cost logic of our actual society, opposed to long term low cost that used to exist.

Do you think a cathedral builder was thinking of short term cost of his building to decide the size ?


Staying in CPP subject, how do you select the good pitch ?
For an electric engine, this is extremely easy as you just have to compare amps to speed, but for ICE i suppose a instantaneous fuel meter is compulsory or just searching for the highest boat speed at a given rpm is enough ?

[TeddyDiver]

Originally Posted by kistinie

Staying in CPP subject, how do you select the good pitch ?

Pyrometer... exhaust temp indicates the engine load.

There are other manufacturer's too but I believe they do bigger units for fishing vessels mostly (www.helseth.no www.hundestedpropeller.dk www.sabb.no www.smv-marine.no... if I recall them right) so two mentioned above are the most suitable for recreational boats.
Brunton's autoprop is actually a VPP (CPP, in my opinion, is just any adjustable propeller even when you got to take it of and/or use tools to set another pitch), not just a folding prop, as it adjusts it's pitch accoding speed and torque..

[FAST FRED]

"How could we correct this problem ?"

For most boats the best from an efficiency , engine service life and cost point is to STOP the owners from installing over sized diesel engines.

Gas car engines may need to run at a small proportion of "rated" power , but for a diesel its an expensive early death to underload.

80% of rated power at 90% rated rpm will keep the engine happy.

Installing a huge & stoopid size for use "when its blowing 40K and you want to blast to windward" is common , although the actual situation is rare.

When did you need it last?


FF

[kistinie]

Humans are very strange animals.

It is just like the 4X4 syndrome
If i want...i can...But it never happens. (for mathematicians, never is 1, 2, 3... % occurrence)

To answer your question
Last time was 2 years ago when on the oceanis 311 i was delivering the rudder control broke, safety rudder connection had too much play so could not stay in front of wind and reef.
Engine was too small also to face wind, so i went 45° to the wind. By chance wind stayed under 45, so i didn't had to cut the sail.
But even if i had no engine i would have found another solution.
Unless you get close to C, slowing time down , always faster, bigger, always more power is often leading to the level 0 of imagination and creativity

So the bigger your diesel is, the richer your dealers will get !
I love this "crime / benefit" approach !

[TeddyDiver]

With VPP a boat needs not a single hp more than with standard screw..
Benefit comes when there'a a need to use less than full power at hull speed or full power with reduced speed . In the first case we deal mostly with motorsailing and in the second one with fishing vessels, tugs etc..

Worst thing to do with diesel engines is to stay by the pier and load batteries engine running... Having an oversized engine doesn't have nothing to do with that

[kistinie]

Originally Posted by TeddyDiver

Worst thing to do with diesel engines is to stay by the pier and load batteries engine running... Having an oversized engine doesn't have nothing to do with that

This is exactly what happens for 90% of rented sail boats and a lots of privately owned.
Just search for serious solar panels and aero generator in an harbour, you get the answer of how energy is produced.
It was the case of my trimaran that only had a broken 25 watt solar panel for 2 pilots, PC, Radar, plotter, irridium, 5 electric pump....

Returning on low speed full power from CPP selecting small pitch, is this a solution to go against strong wind with low power engine, i guess yes ?

[apex1]

The statement that CPP disappeared is not right. The opposite is correct! There are more CPP manufacturers today than we had in the 60´s. Most of them are mentioned above, but do´nt forget "Maxprop" and "Gori" for the low power (or sailing) range; and "Piening" and "ZF" for higher outputs.
We install mainly Hundested in our displacement boats.
The often heared statement that these systems are expensive is definetily wrong! In a fair price comparison you´ll find a CPP installation is as cheap (or expensive) as a conventional gearbox and drivetrain of the same quality. Boatbuilders often compare the cheapest available gearbox, shaft and prop with the high end Scandinavian CPP installation and find a noticeable difference then. Naturally....
Edited: I just found an old calc.(2005) and the difference was 2.300€ per drivetrain (CPP above the gearbox), but that was on a 36mtr. and each engine was about 180.000€. So I do´nt call that a difference.
The whole Scandinavian fishing fleet uses CPP only! And we all know that fishermen have no money to waste.
The main advantage of a CPP is the fact that you allways operate your Diesel on a perfect load setting, that gives the most efficient consumption and keeps your engine happy.
Fast Fred, it is not the question how often you have to go uphill in a force 10 storm. But if your yacht crosses the Atlantic at 50% power setting or just the pond from Ibiza to Mallorca at 85% makes a huge difference. And that is everyday use on larger displ. yachts.
Regards
Richard

[kistinie]

Disappeared ...from leisure boats 20 to 40 feet it seems.

Not that expensive ? This can be a relative consideration :-)

What would be the minimum budget to equip a 10 to 15 hp motor for a true CPP i can control from 0 to + - max pitch ?
This size 10/15 even 20 hp is a very common size for sailing boat

Maxprop is a true full CPP ?
Can i change the pitch as i desire manually from a remote control or is it automatic ?

[apex1]

Originally Posted by kistinie

Disappeared ...from leisure boats 20 to 40 feet it seems.
There was never a big number of boats in that range equipped with CPP, so nothing could disappear.
Not that expensive ? This can be a relative consideration :-)

No that is not relative. I said "fair comparison"....

What would be the minimum budget to equip a 10 to 15 hp motor for a true CPP i can control from 0 to + - max pitch ?
This size 10/15 even 20 hp is a very common size for sailing boat
These questions the market should answer, not a boatbuilder.
Maxprop is a true full CPP ?
Can i change the pitch as i desire manually from a remote control or is it automatic ?
Are you shure, you know what a CPP installation is?

Regards
Richard

[kistinie]

Originally Posted by apex1

There was never a big number of boats in that range equipped with CPP, so nothing could disappear.

No that is not relative. I said "fair comparison"....

These questions the market should answer, not a boatbuilder.

Are you shure, you know what a CPP installation is?

Mmmmm I am dispointed, No informations ...
Stonewalling exercise