Ocean Running Techniques
#71
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Re: Ocean Running Techniques
You need to mark on your drive/tab indicator the neutral point. This will help you immensly.
#72
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Re: Ocean Running Techniques
Originally Posted by thisistank
You need to mark on your drive/tab indicator the neutral point. This will help you immensly.
#73
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Re: Ocean Running Techniques
Originally Posted by StillHaulin@61
I wonder how a 23' hull would react with a slightly negative tab, but a slightly positive trim. Which device would dominate, the trim tabs or the outdrive?
Seas permitting, I'll make a solo run on Saturday to try and find this elusive "edge". Obviously, I'll keep my speed down during this learning curve, but is there any kind of warning sign before going OVER this edge?
Seas permitting, I'll make a solo run on Saturday to try and find this elusive "edge". Obviously, I'll keep my speed down during this learning curve, but is there any kind of warning sign before going OVER this edge?
#74
The BAD Guy
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Re: Ocean Running Techniques
I just gotta say that Apache video was the $hit!! Thought those crazy mofo's were going to flip at the end
Sorry for the hijack.......proceed with discussion
Sorry for the hijack.......proceed with discussion
#75
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Re: Ocean Running Techniques
[QUOTE=noboat][QUOTE=StillHaulin@61It make sense that trimming down will make this type of launch less probable, but where is the balance point?[/QUOTE]
The Outrage replaced my model the Revenge; same hull just different deck styling, the latter version is nicer looking. If people are looking for a good center console with decent rough water capabilities in the 22 ft. range check out an Outrage.
The 22 Revenge cuddy; has a tendency to be bow heavy, forward center of gravity. They do fly and lands very nice if done properly, right trim, and shift the center of gravity more towards the stern via throttles. Not exactly sure how to explain the technique; other than if you tried it in another 22ft boat, you may recreate that famous vertical Super boat (I think) picture! The balance point is dif. On each model and make of boat, sometimes even models using the same hull design will require different technique. My Revenge was a hammy down from my Dad. He bought it new and without a sea trial, dealer because it was in the water already, plus we lived on a beach handed us the key’s and off we went. In defense of the sales guy, we happened to arrive at the marina by boat on a day trip. So the guy just assumed experience they are boaters. Think one of the things sellers even if private should tell people even if they are boat owners, little things that may help them figure a basic technique for that boat so they don't have to learn the edge the hard way. Insurance rates might go down if, less accidents occur. The balance point on the Revenge cuddy, is going to be a lot different than the Revenge center console with no cuddy.
The best defense for not stuffing it, is figure out the center of gravity:
----------------------------------------------------------------------------------
NASA wrote: The center of gravity is a geometric property of any object. The center of gravity is the average location of the weight of an object. We can completely describe the motion of any object through space in terms of the translation of the center of gravity of the object from one place to another, and the rotation of the object about its center of gravity if it is free to rotate. If the object is confined to rotate about some other point, like a hinge, we can still describe its motion. In flight, both airplanes and rockets rotate about their centers of gravity. A kite, on the other hand, rotates about the bridle point. But the trim of a kite still depends on the location of the center of gravity relative to the bridle point, because for every object the weight always acts through the center of gravity.
The center of gravity is a geometric property of any object. The center of gravity is the average location of the weight of an object. We can completely describe the motion of any object through space in terms of the translation of the center of gravity of the object from one place to another, and the rotation of the object about its center of gravity if it is free to rotate. If the object is confined to rotate about some other point, like a hinge, we can still describe its motion. In flight, both airplanes and rockets rotate about their centers of gravity. A kite, on the other hand, rotates about the bridle point. But the trim of a kite still depends on the location of the center of gravity relative to the bridle point, because for every object the weight always acts through the center of gravity.
Determining the center of gravity is very important for any flying object. How do engineers determine the location of the center of gravity for an aircraft which they are designing?
In general, determining the center of gravity (cg) is a complicated procedure because the mass (and weight) may not be uniformly distributed throughout the object. The general case requires the use of calculus which we will discuss at the bottom of this page. If the mass is uniformly distributed, the problem is greatly simplified. If the object has a line (or plane) of symmetry, the cg lies on the line of symmetry. For a solid block of uniform material, the center of gravity is simply at the average location of the ^M physical dimensions. (For a rectangular block, 50 X 20 X 10, the center of gravity is at the point (25,10, 5) ). For a triangle of height h, the cg is at h/3, and for a semi-circle of radius r, the cg is at (4*r/(3*pi)) where pi is ratio of the circumference of the circle to the diameter. There are tables of the location of the center of gravity for many simple shapes in math and science books. The tables were generated by using the equation from calculus shown on the slide.
For a general shaped object, there is a simple mechanical way to determine the center of gravity:
1. If we just balance the object using a string or an edge, the point at which the object is balanced is the center of gravity. (Just like balancing a pencil on your finger!)
2. Another, more complicated way, is a two step method shown on the slide. In Step 1, you hang the object from any point and you drop a weighted string from the same point. Draw a line on the object along the string. For Step 2, repeat the procedure from another point on the object You now have two lines drawn on the object which intersect. The center of gravity is the point where the lines intersect. This procedure works well for irregularly shaped objects that are hard to balance.
If the mass of the object is not uniformly distributed, we can characterize the mass distribution by a function w(x) which indicates that the weight is some function of distance x from a reference line. If we can determine the form of the function, there are methods to perform a calculus integration of the equation. We will use the symbols "S[ ]dx" to denote the integration of a continuous function. Then the center of gravity can be determined from:
cg = (S[x * w(x)]dx) / (S[w(x)]dx)
If we don't know the actual functional form, we can numerically integrate the equation using a spreadsheet by dividing the distance into a number of small distance segments and determining the average value of the mass (or weight) over that small segment. Taking the sum of the average value times the distance times the distance segment divided by the sum of the average value times the distance segment will produce the center of gravity.
--------------------------------------------------------------------------------
I plan on going to Tres Martin more for interest, but, I also support his efforts in making better and therefore safer go fast driver's.
Originally Posted by noboat
Every hull is different, so you have to find it. Mine is right before the hull really loosens up for top speed. It's hard to describe but you can kind of feel it slightly holding you back and keeping the boat more level. This obviously scrubs speed but it also makes the boat stay level. Like I said, it's about neutral trim and slightly negative tab.
Unfortunately the only way to find the "edge" is to go past it a few times. So get some passengers that don't scare easily!
Unfortunately the only way to find the "edge" is to go past it a few times. So get some passengers that don't scare easily!
Originally Posted by thisistank
Nothing floats (in the air) and lands like a whaler. There is no other feeling like it in a boat. I absolutely love 'em. the 22 (Outrage if I'm not istaken) is the best boat in their line up. IMHO.
it's small craft warning time....then I call no joy.
it's small craft warning time....then I call no joy.
Originally Posted by StillHaulin@61
WOW!
Now I understand how you can stuff it!
Correct me if I'm wrong ..... but it seems that if you launch at an angle which allows the drive to return to the water first, it's impact, and resulting drag will virtually pull the nose down hard into the water.
It make sense that trimming down will make this type of launch less probable, but where is the balance point?
In average 2-4' seas, how much of the hull should be in the water to achieve a reasonable balance?
Now I understand how you can stuff it!
Correct me if I'm wrong ..... but it seems that if you launch at an angle which allows the drive to return to the water first, it's impact, and resulting drag will virtually pull the nose down hard into the water.
It make sense that trimming down will make this type of launch less probable, but where is the balance point?
In average 2-4' seas, how much of the hull should be in the water to achieve a reasonable balance?
The 22 Revenge cuddy; has a tendency to be bow heavy, forward center of gravity. They do fly and lands very nice if done properly, right trim, and shift the center of gravity more towards the stern via throttles. Not exactly sure how to explain the technique; other than if you tried it in another 22ft boat, you may recreate that famous vertical Super boat (I think) picture! The balance point is dif. On each model and make of boat, sometimes even models using the same hull design will require different technique. My Revenge was a hammy down from my Dad. He bought it new and without a sea trial, dealer because it was in the water already, plus we lived on a beach handed us the key’s and off we went. In defense of the sales guy, we happened to arrive at the marina by boat on a day trip. So the guy just assumed experience they are boaters. Think one of the things sellers even if private should tell people even if they are boat owners, little things that may help them figure a basic technique for that boat so they don't have to learn the edge the hard way. Insurance rates might go down if, less accidents occur. The balance point on the Revenge cuddy, is going to be a lot different than the Revenge center console with no cuddy.
The best defense for not stuffing it, is figure out the center of gravity:
----------------------------------------------------------------------------------
NASA wrote: The center of gravity is a geometric property of any object. The center of gravity is the average location of the weight of an object. We can completely describe the motion of any object through space in terms of the translation of the center of gravity of the object from one place to another, and the rotation of the object about its center of gravity if it is free to rotate. If the object is confined to rotate about some other point, like a hinge, we can still describe its motion. In flight, both airplanes and rockets rotate about their centers of gravity. A kite, on the other hand, rotates about the bridle point. But the trim of a kite still depends on the location of the center of gravity relative to the bridle point, because for every object the weight always acts through the center of gravity.
The center of gravity is a geometric property of any object. The center of gravity is the average location of the weight of an object. We can completely describe the motion of any object through space in terms of the translation of the center of gravity of the object from one place to another, and the rotation of the object about its center of gravity if it is free to rotate. If the object is confined to rotate about some other point, like a hinge, we can still describe its motion. In flight, both airplanes and rockets rotate about their centers of gravity. A kite, on the other hand, rotates about the bridle point. But the trim of a kite still depends on the location of the center of gravity relative to the bridle point, because for every object the weight always acts through the center of gravity.
Determining the center of gravity is very important for any flying object. How do engineers determine the location of the center of gravity for an aircraft which they are designing?
In general, determining the center of gravity (cg) is a complicated procedure because the mass (and weight) may not be uniformly distributed throughout the object. The general case requires the use of calculus which we will discuss at the bottom of this page. If the mass is uniformly distributed, the problem is greatly simplified. If the object has a line (or plane) of symmetry, the cg lies on the line of symmetry. For a solid block of uniform material, the center of gravity is simply at the average location of the ^M physical dimensions. (For a rectangular block, 50 X 20 X 10, the center of gravity is at the point (25,10, 5) ). For a triangle of height h, the cg is at h/3, and for a semi-circle of radius r, the cg is at (4*r/(3*pi)) where pi is ratio of the circumference of the circle to the diameter. There are tables of the location of the center of gravity for many simple shapes in math and science books. The tables were generated by using the equation from calculus shown on the slide.
For a general shaped object, there is a simple mechanical way to determine the center of gravity:
1. If we just balance the object using a string or an edge, the point at which the object is balanced is the center of gravity. (Just like balancing a pencil on your finger!)
2. Another, more complicated way, is a two step method shown on the slide. In Step 1, you hang the object from any point and you drop a weighted string from the same point. Draw a line on the object along the string. For Step 2, repeat the procedure from another point on the object You now have two lines drawn on the object which intersect. The center of gravity is the point where the lines intersect. This procedure works well for irregularly shaped objects that are hard to balance.
If the mass of the object is not uniformly distributed, we can characterize the mass distribution by a function w(x) which indicates that the weight is some function of distance x from a reference line. If we can determine the form of the function, there are methods to perform a calculus integration of the equation. We will use the symbols "S[ ]dx" to denote the integration of a continuous function. Then the center of gravity can be determined from:
cg = (S[x * w(x)]dx) / (S[w(x)]dx)
If we don't know the actual functional form, we can numerically integrate the equation using a spreadsheet by dividing the distance into a number of small distance segments and determining the average value of the mass (or weight) over that small segment. Taking the sum of the average value times the distance times the distance segment divided by the sum of the average value times the distance segment will produce the center of gravity.
--------------------------------------------------------------------------------
I plan on going to Tres Martin more for interest, but, I also support his efforts in making better and therefore safer go fast driver's.
Last edited by Zudnic; 07-25-2006 at 08:42 PM.
#76
Gold Member
Gold Member
Re: Ocean Running Techniques
Originally Posted by Panther
Just a little tab and that trip/stuff would have never happened.
WHAT TABS?????
We had none!!! We discovered a electrical problem on the Team Apache Boat at the start of the race. That’s why we started 15 minutes late. We had a lot of time and water to make up… Every time I touch the trim tabs or the drives. The engines would lose power. Too much voltage needed to run all the trim motors with shorted batteries. So I set all the trims to a “happy medium general type setting” and told the crew to hold on baby!!! We are going for it..
Surprisingly we finished only of few seconds behind the first boat in spite of the spine and wound up in second place UIM world Champions 1985
Ahhh the good old days
Bobby Saccenti
Last edited by Bob Saccenti; 07-25-2006 at 09:03 PM.
#77
Registered
Re: Ocean Running Techniques
Originally Posted by Bob Saccenti
WHAT TABS?????
We had none!!! We discovered a electrical problem on the Team Apache Boat at the start of the race. That’s why we started 15 minutes late. We had a lot of time and water to make up… Every time I touch the trim tabs or the drives. The engines would lose power. Too much voltage needed to run all the trim motors with shorted batteries. So I set all the trims to a “happy medium general type setting” and told the crew to hold on baby!!! We are going for it..
Surprisingly we finished only of few seconds behind the first boat in spite of the spine and wound up in second place UIM world Champions 1985
Ahhh the good old days
Bobby Saccenti
We had none!!! We discovered a electrical problem on the Team Apache Boat at the start of the race. That’s why we started 15 minutes late. We had a lot of time and water to make up… Every time I touch the trim tabs or the drives. The engines would lose power. Too much voltage needed to run all the trim motors with shorted batteries. So I set all the trims to a “happy medium general type setting” and told the crew to hold on baby!!! We are going for it..
Surprisingly we finished only of few seconds behind the first boat in spite of the spine and wound up in second place UIM world Champions 1985
Ahhh the good old days
Bobby Saccenti
AWESOME JOB!!!
#78
Geronimo36
Gold Member
Re: Ocean Running Techniques
Originally Posted by Bob Saccenti
WHAT TABS?????
We had none!!! We discovered a electrical problem on the Team Apache Boat at the start of the race. That’s why we started 15 minutes late. We had a lot of time and water to make up… Every time I touch the trim tabs or the drives. The engines would lose power. Too much voltage needed to run all the trim motors with shorted batteries. So I set all the trims to a “happy medium general type setting” and told the crew to hold on baby!!! We are going for it..
Surprisingly we finished only of few seconds behind the first boat in spite of the spine and wound up in second place UIM world Champions 1985
Ahhh the good old days
Bobby Saccenti
We had none!!! We discovered a electrical problem on the Team Apache Boat at the start of the race. That’s why we started 15 minutes late. We had a lot of time and water to make up… Every time I touch the trim tabs or the drives. The engines would lose power. Too much voltage needed to run all the trim motors with shorted batteries. So I set all the trims to a “happy medium general type setting” and told the crew to hold on baby!!! We are going for it..
Surprisingly we finished only of few seconds behind the first boat in spite of the spine and wound up in second place UIM world Champions 1985
Ahhh the good old days
Bobby Saccenti
I'll give you a call soon!
Frank
#79
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Re: Ocean Running Techniques
Originally Posted by BajaRunner
Chicken
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Re: Ocean Running Techniques
Originally Posted by Bob Saccenti
WHAT TABS?????
We had none!!! We discovered a electrical problem on the Team Apache Boat at the start of the race. That’s why we started 15 minutes late. We had a lot of time and water to make up… Every time I touch the trim tabs or the drives. The engines would lose power. Too much voltage needed to run all the trim motors with shorted batteries. So I set all the trims to a “happy medium general type setting” and told the crew to hold on baby!!! We are going for it..
Surprisingly we finished only of few seconds behind the first boat in spite of the spine and wound up in second place UIM world Champions 1985
Ahhh the good old days
Bobby Saccenti
We had none!!! We discovered a electrical problem on the Team Apache Boat at the start of the race. That’s why we started 15 minutes late. We had a lot of time and water to make up… Every time I touch the trim tabs or the drives. The engines would lose power. Too much voltage needed to run all the trim motors with shorted batteries. So I set all the trims to a “happy medium general type setting” and told the crew to hold on baby!!! We are going for it..
Surprisingly we finished only of few seconds behind the first boat in spite of the spine and wound up in second place UIM world Champions 1985
Ahhh the good old days
Bobby Saccenti