Chris Wood
Well-Known Member
- Joined
- Jan 4, 2002
- Messages
- 3,493
Lifting Or Non-Lifting Prop - How Can You Tell?
- Thread starter Tim van Schyndel
- Start date
Help Support Intlwaters:
Chris,
When I repitch a well known boaters ABC 1614/3 chopper for a 21-mono, I bend out aprox. .040" to .050"
On the leading edge from .3 to .6 on the leading edge. Then I repitch the center of the
Blade which also changes the trailing edge. So it keeps the progression that I am looking
for throughout the whole blade. I can tell you not many people have enough motor to pull
A really modified propeller. I think you would do better by just stepping up to the next size
propeller and just reduce the blade area and diameter. Now you will have another option available, just buy a
ABC 1615/3 chopper with a 20 degree rake. These have 10 % more pitch and 5% more rake and you will see
around a 3 to 5 MPH change in speed and the roosertail will only raise about 12" off the water.
We are currently working with a 1815 and 1817 with 17 degrees of rake on our 21 hydros and we have seen
some very good results so far. The fun part is to try and figure out what the best progression of numbers that work
the best throughout the whole blade area. I can tell you when you get close you will be amazed how fast these
new blades accelerate with just 5 to 7 more degrees of rake angle added. We have added anywhere from 3 to 7 MPH
on three different set ups so far. I will be able to tell you more in the next three weeks once more testing is done and
we go to our first race and see how they handle the competition.
Keep Testing With Good Record Keeping,
Mark Sholund
When I repitch a well known boaters ABC 1614/3 chopper for a 21-mono, I bend out aprox. .040" to .050"
On the leading edge from .3 to .6 on the leading edge. Then I repitch the center of the
Blade which also changes the trailing edge. So it keeps the progression that I am looking
for throughout the whole blade. I can tell you not many people have enough motor to pull
A really modified propeller. I think you would do better by just stepping up to the next size
propeller and just reduce the blade area and diameter. Now you will have another option available, just buy a
ABC 1615/3 chopper with a 20 degree rake. These have 10 % more pitch and 5% more rake and you will see
around a 3 to 5 MPH change in speed and the roosertail will only raise about 12" off the water.
We are currently working with a 1815 and 1817 with 17 degrees of rake on our 21 hydros and we have seen
some very good results so far. The fun part is to try and figure out what the best progression of numbers that work
the best throughout the whole blade area. I can tell you when you get close you will be amazed how fast these
new blades accelerate with just 5 to 7 more degrees of rake angle added. We have added anywhere from 3 to 7 MPH
on three different set ups so far. I will be able to tell you more in the next three weeks once more testing is done and
we go to our first race and see how they handle the competition.
Keep Testing With Good Record Keeping,
Mark Sholund
Christian Lucas
Well-Known Member
- Joined
- Aug 23, 2012
- Messages
- 339
Hi,
about history of the x4.. serie Octura propellers . for me the blue Z50 is the grandpa of this propellers . Mybe allso the Graupner x serie are close and a very old propellerserie back from the 60ties you will find them in Graupner catalog early made of red nylon plastic .
But the x4.. serie was the first that has a light cuping at the trailing edge that make this propeller the first easy starting propeller . With all other befor you have to push the boat and not everytime the propeller bit and acclerates the boat. In Germany we bend a small cuping in the trailing edge of the red nylon propeller and get so the good starting . This was the basic of fast electric as this guys want to lay down the boat in the water and switch on the motor to rn the boat. With the old style propeller this was imposible. The propeller turn high and sucks air and makes crazy sound . That's all. We start at Graupner with a new hydropropeller serie with wedge cuping at the trailing edge that worke easy and everybody could run now surface pircing propeller driven boats.
The pic show comparison but as you see not 100% .
Last pic i will show you a ruschian tethered line propeller that was designet to counteract lift and hold stren down so the rigger was able to run on calm ,windy conditions when other get not trust in the water as the boat was jumping to high.
The drawing is from the book "High Speed Small Craft " written by Comander Peter Du Cane . Head designer of Vosper In Great Britain that show the rake in the blade .
Last some experiance ,i solder the blade of a x440 to a conical hub and the other are to compare a x440/3 with a higher pitched x440/3 where i cout small slot at the hub for leading edge and trailing edge bend them and hard solder it in this position . runs great but need moore cup to start.
about history of the x4.. serie Octura propellers . for me the blue Z50 is the grandpa of this propellers . Mybe allso the Graupner x serie are close and a very old propellerserie back from the 60ties you will find them in Graupner catalog early made of red nylon plastic .
But the x4.. serie was the first that has a light cuping at the trailing edge that make this propeller the first easy starting propeller . With all other befor you have to push the boat and not everytime the propeller bit and acclerates the boat. In Germany we bend a small cuping in the trailing edge of the red nylon propeller and get so the good starting . This was the basic of fast electric as this guys want to lay down the boat in the water and switch on the motor to rn the boat. With the old style propeller this was imposible. The propeller turn high and sucks air and makes crazy sound . That's all. We start at Graupner with a new hydropropeller serie with wedge cuping at the trailing edge that worke easy and everybody could run now surface pircing propeller driven boats.
The pic show comparison but as you see not 100% .
Last pic i will show you a ruschian tethered line propeller that was designet to counteract lift and hold stren down so the rigger was able to run on calm ,windy conditions when other get not trust in the water as the boat was jumping to high.
The drawing is from the book "High Speed Small Craft " written by Comander Peter Du Cane . Head designer of Vosper In Great Britain that show the rake in the blade .
Last some experiance ,i solder the blade of a x440 to a conical hub and the other are to compare a x440/3 with a higher pitched x440/3 where i cout small slot at the hub for leading edge and trailing edge bend them and hard solder it in this position . runs great but need moore cup to start.
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