Adjustable propeller pitch for surface pising propeller

[Ch.Lucas]

adjustable propeller pitch for surface pircing propeller

Hi,
something different, how can you make the propeller pitch adjustable for a semi-submersible propeller without the propeller blades having to be movable?
Here are a few pictures, in the case of semi-submersible propellers, only the blades that are immersed in the water are relevant for the drive. If two opposing propellers are placed next to each other, you can lift the propwalk on the one hand, but you can also adjust the angle of the valley to the straight line of travel as viewed in the angle of attack. Since it would be a bit cumbersome to adjust the whole propeller shaft, it is best to use two Arneson Drives. You have to remove the Skeg fins and put a rudder blade between the propellers.
Now you can adjust the propeller inflow at an angle and thus have the option to start with flatter propellers for better acceleration and then to switch to a higher propeller pitch to be able to reach a higher top speed. In order to relieve the joints at maximum performance, the drives are installed at an angle so that the couplings have to achieve as little angle compensation as possible on a steep incline. See the pictures of the drive in the boat.

Happy Amps Christian

[Ch.Lucas]

Hi,
more pics

Happy Amps Christian

[Ch.Lucas]

Hi,
more to know about. If you have run a outrigger in a corner , the normal,outrigger comptition has right hand corner, you will notice that the motot rev up and the load is lower. This is a function of to run with the propwalk and becaus the transo slide left that lower the propeller pitch. To run right hand corner comes from history of ic. motor racing , this combustion motors have less torque and get in problems when the load rise. So the right ha d corner let the engine lower load rev easyer. With electric motors you will accelerate the rigger in a corner if you run a counter rev propeller. Yes no easy theroetic lessen but it is.

Happy Amps Christian

[eXoNerated]

Hi Christian,
I have these photos from a year ago. Do you have it at least working with the radio yet? Can we see it actually work? A twin thai longtail could do the same thing an is less complicated. They have the rc model running very well already. There are videos of them working. Can we get a demonstration of yours and this thing it does when turning?


Regards,
Hubert

[Ch.Lucas]

Hi ,
but no one of all them has the idea to use such drive to get different propeller pitch and no one has a twin surface drive with counter rotating propellers to get the effect. You see you can not understand the innovation that is in this idea. If they have a twin drive , they use only different rev of the propellers to for stearing or the heve only a singel propdrive and do stearing , that all. That is old way everybudy knows. Yes i have testet it .

Happy Amps Christian

[Dr. Jet]

This is an interesting line of thinking and it took me a moment to realize exactly what you are doing, but something tells me you don't get something for free. Your concept seems workable in an ideal world, but at start-up, both propellers will be in a submerged condition. They will only go to surface-piercing mode when the hull is at planing attitude. How will your system work with this transition? I see you have it set-up in a cat; that's a good choice. Making it work in a mono hull that rolls to the side in a turn may be problematic.

Or perhaps this may work: The VAPSA System (Variable Angle Propeller Shaft Assembly) is only activated at speed when increased acceleration is required out of a turn. Things would have to happen really fast and it would probably need to be computer-programmed into the throttle system with some sort of override when the props are submerged. There's a lot of complexity and extra parts in your design, I would be interested in seeing how it affects performance.

[eXoNerated]

How do you know what they know over there? Theirs runs so where's the video of better from your test then? Same photo from 2 years ago theres no radio gear in it, You took this photo but not that one? Why would I understand theory doing nothing or understand a stand a still photo of it. The principles you read can be read in any maritime engineering book by anyone. What so special about this knowlegde? That sits on a lawn chair? You want people to understand and adopt theory without showing them it works. Thats grand. It will fall to the bottom soon enuf what I understand is you especially will never control it well enough while driving in a real situation to make any use of it other than fun running. Since you are no EE you cannot code autonomy but nice toy.

[Ch.Lucas]

Hi Dr. Jet,
there is no problem when starting off because you can easily adjust both propeller shafts parallel to the boat's central axis. The servos make every position of the propeller shafts possible. So if you stand in parallel, the boat drives like two normal counter-rotating propellers. When the boat has started to glide, you can move to different positions with the propeller shaft angles, depending on whether you need a little less incline to accelerate better out of a curve or the incline slowly increases to achieve a higher top speed. In curves you will support the rudder blade with the steering drives, as everyone does with a stearable Propshaft drive like a Arneson drive.
I have tested this with also a single drive with seperate ruder.
xboy you see you hav not understod this drives as everything you do not understand, go home or go fishing, the fish are happy because you can't catch one anyway.Trolling is the true , you are a Troll.

Happy Amps Christian

[Dr. Jet]

Hi Dr. Jet,
there is no problem when starting off because you can easily adjust both propeller shafts parallel to the boat's central axis. The servos make every position of the propeller shafts possible. So if you stand in parallel, the boat drives like two normal counter-rotating propellers. When the boat has started to glide, you can move to different positions with the propeller shaft angles, depending on whether you need a little less incline to accelerate better out of a curve or the incline slowly increases to achieve a higher top speed. In curves you will support the rudder blade with the steering drives, as everyone does with a stearable Propshaft drive like a Arneson drive..........

Happy Amps Christian

Here's a hypothetical thought that would be easy to program into a radio. I haven't fully contemplated how it would work, but it would be something like this: Forget about using the drives for steering. Use the rudder. Then, slave the drive angle servo to the steering channel in such a way that the more you turn the rudder (in either direction) the closer together the propellers become. In other words; when turning , you would have low pitch, when going straight, you would have high pitch. That's easier than fooling with a separate input on the transmitter. You could even program this feature to be "On" or "Off" at any given time.

[eXoNerated]

Now you just need to see it run. You see the Thai that "dont know" about your genius are running very flat without it.

Regards
Hubert

[eXoNerated]

Does your boat run 50 mph? Can we see? U see the super simple construction of the longtail? The 3rd world engineer u claim cannot match you genius for Less than 2 dollars in brushed motors runs your record speed still with brushed power and a 5 dollar 2 channel radio. I could build this in 30min and smoke the Arneson drive boat. It can also handle more torque than a plastic arneson drive and will last virtually forever run after run. This is "fun" running for cheap and without great complication. They build their own props too .

Regards
Hubert

[Ch.Lucas]

Hi,
all this boats have nothing to do with changing propeller pitch . You see , you do not understand this technic . Better you play with your boat.

Happy Amps Christian

[eXoNerated]

I understand pitch and how it works every bit as well as you but I also wonder why anyone other than a didactic toymaker would be interested in SLOWER with more complications and broken parts on a "fast" electric boat forum? What good is this when it's still sitting at the start line broken or delayed as it requires the sailor to throw gang signs at the radio while the other boat has finished the race?
Complicated slower and less durable is the genius ill never understand.

Plastic arneson drive is also worthless for any real torque handling. No good except for a pool toy. Evolve and I guess if it runs at all it doesnt run 50 or we's get to see it. When you ran the boat what esc did you use? More durable is to put the standard solid prop/shaft combos on tilt pan apparatus. Very simple and maintains a bullet proof trasmission THAT WILL LAST with much more range to adjust pitch. Copying the Arneson drive (someone elses genius) is easy coming up with something practical on your own for an FE model no so much. Put this through the paces with anything other than toy power and it falls apart. Submit it back to Graupner. The Thai dont understand according to you but they are the ones with boats that use this pitch changing priciple on the regular and post the faster small twin the forum can actually see run. They reached 50 mph with very little effort in a boat with simple hardware that will last forever.

But anyway here is a real arneson drive for a rc boat wheres the "innovation"?






“Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius — and a lot of courage to move in the opposite direction.”
― E.F. Schumacher

Regards
Hubert

[Ch.Lucas]

Hi,
so for all Reader here what is the innovation ? The innovation is that the boat can accelerate faster . It hit topspeed in shorter time as the motor see a lower pitch propeller that produce higher trust as the motor are less load rev higher . When the boat reach the speed of the lower pitch propeller the pitch can now rised like it is used to get the topspeed that is needed for the race. Not a fixed pitch propeller has only a fixed topspeed that can only raised by rising the motor rpm. This is only possible for phase switch or flux changing motors but always with the coast of much higher load for the motors. The propeller pitch changing is the better and energy saver way. Have a look at airplanes , most airplane have a pitch control for propeller driven planes. Every pilot know how to use this extra trust changing device.
Also a boat can not only better accelerate it has better race performance as the pilot can fast and easy control the trust this way has higher efficance than to control trust by electronic esc wenn control rpm. Part speed has less efficancy and it works by lowering the rpm. If you then want to accelerate out of a corner the motor has to rev up. With changing pitch the drive rev higher at lower speed and now after the corner the motor has much higher power stored in it selv that helps much when the boat accelerate for the straight lane.
So with such system the over all efficancy is much higher by faster respond time faster acceleration and higher topspeed.
For all this you have to pay with electronic esc devise with less efficancy with slower acceleration and higher energy consumption and slower topspeed. So i hope that you have now understod the dirffence of the longtail boats and the twin arneson drive . I have a arneson drive ,i need no picture from you . This cheap and good working stearable drives are made by me and sold by Graupner million drives a year. Spend me a high free income doing nothing only hold open my hands. Many modelboater in the world have used this drive mounted on the hydrocup racer , the KeyWest offshore tunnelboat and the Corbra monohull and many more .

Happy Amps Christian

[eXoNerated]

If the other is already faster without it coz you start with no pitch so it wont make a difference. Driving It that way will require a real technique you will not master in a pool to say it will work. Definitively "innovation" is supposed to be something new. The arneson drive has been around a long time and could have always been used this way. The one u posted has no real kahunas for a high performance boat. So whats new. The higher pitch also comes with amperage draw and by the time you throw your gang signs at the radio the competition has the hole shot simply on reaction time and gone you lost!!! Where you think you run the Bonneville flats? If u think there's an advantage in these short periods of time show us . Theory sounds good but nothing practical is considered. You aslo cannot writre the code. I already have written it for the canards. Now they need a flux switching motor to run this thing. Come on man really? You dont have that yourself or a drive to run it. What modeler here will? What a dream Chris what a dream but it might bring validation of your genius to everyone. Isnt that the true purpose of the thread anyway?


Regards
Hubert