Prop recommendations - Different pitches & diameters, plus 2-blade vs 3-blade

[eXoNerated]

Oh I'm def done but your post is refreshing enough. At least your honest, can spell, and kept your mouth closed because you did not know. I know you didn't make the comment but there is no need to address people that place no value in exacting science. Trail an error with no definitive initial direction or solid understanding of how they work from a physical sense, just isn't how I do things. Different strokes......

Without you knowing at least you can speak the language and value physical science. As an engineer I don't see this vast divide between theory and "empirical" evidence. To me empirical evidence is the information you gather when you remove the theoretical model from his controlled lab environment into an uncontrolled one with many variables, like water temp., density, etc. I spoke to that 1st but he couldn't understand it the way I told it to him. But its all good. I don't explain things a simple way simply because I'm not simple minded. Most times the optimal theoretical model still ends up being the best one to introduce to the empirical environment. isnt that the point of science

Regards
Hubert

[HTVboats]

I don't make any claim on being an expert. I do race and have been to record trials. So without an engineering degree (my college days were interrupted by the Marines and a trip to Viet Nam) I do know who Bernoulli is and what the shape and affect trailing edge water breaking off a prop does. Also you can affect pressure on the face of the blade with the TE shape and cup. I know a few guys who can take a pliers, bend some blades, and totally change how a boat runs. I bend some from time to time also but don't have the "black art" down.
I was testing motors this week on a "mule" (boat with known parameters) and with two different props. The motors are for a twin and I wanted to make sure they were close in watts. After seeing they were very close I looked at the slower prop which was cavitating getting on plane. So I cupped the tips (hammer and SS ball) not precision and went from 55 to 63mph. Amps went up from 170 to 220 and watts 2600 to 3300. Rpm dropped from 27000 to 24000. So trial and error with a bit of experience does pay off.
As I stated before know pitch and diameter and keep track of how it affects your boat. From there learn blade profiles and rake. Use good data loggers and GPS's that do more than give top speed
.72 mph 1817 38.jpg.
I don't do much with SAW runs antmore but do know my corner entry and exit speeds. I test off my dock quite a bit and keep a log book with info like amps, rpm, watts, speed, temps, motor and battery used, run distance and end voltage. I run mono's, hydro's, cats and OB tunnels.
No formal degree so I can't say the knowledge of vapor cavity shape or distribution will help me. I must be a failure. Oh yeah check the NAMBA and IMPBA record books, you might see my name or my son and grandson.
Mic

[eXoNerated]

Nice resume MIC. I know all about it already. Have fun with your tunnels. They are fast. You've come a long way in "FE" the last few years. Do you think that is that because of the PROP you run being so much better than everybody elses or can you actually drive and have a decent setup on your boats? That's not the same thang ya know..... Do you prepare you own props? What do you do that's special with them then?

THESE WOULD BE JUST SOME OF THE REASONS YOU EXAMINE THE PROP IN THE CONTROLLED ENVIRONMENT AND NOT THE ENTIRE VESSEL AND ALL THE OTHER VARIABLES A COMPETITIVE RACE WOULD ENTAIL . NOW THE OP CAN CHANGE HIS MIND BUT THE TOPIC WAS PROPS NOT COMPETITION TUNNELS AND THE BEST PROP FOR THEM

Theres no black art to ABC 's prop design. He uses MEF. Maritime Engineering Fundamentals



Regards
Hubert

[eXoNerated]

Black art is when someone that knows nothing about it but through empirical evidence of trying everything or plain luck they found something that worked. Many times they cannot tell you why if they did not have some right or wrong theory in their head, and approached it in incremental steps under that premise taking notes. Otherwise they can't really tell you WHY it works and thats what makes it so called a black art. Nah fam there's def people that have a good idea of exactly what to do without running the boat or being the driver. JS(ABC) is one.

Regards
Hubert

[eXoNerated]

And then why does it always come to this between theorist and empiricist? Here's the difference between the two. An empiricist may say remove material "here" and "here" from a prop because when I did it was fast. The theorist or "Thinker" would possibly use the information in the attachment to determine exactly where to remove material for the best surface piercing super cavitation performance. Where they may consider things like leading edge flutter. The empiricist may run into a snag at some point. A wall in which he cannot increase his performance. He cant see through racing what's happening now.So he becomes dogmatic and now he's surely done because what he saying may be or may not be correct. The other problem is it usually takes the empiricist much longer to arrive at the same level of performance as the theorist/empiricist.

Regards
Hubert

[HTVboats]

Hugh just keep talking, you're good at the keyboard. So what races have you actually run? Let alone show up and prove your great knowledge. Been waiting since you spouted off in 2012. Still no Hugh sightings. You keep name dropping. AB JS JA like your one of the boys. Until you actually do something off the keyboard your just a "troll". How many forums have you been banned from? You will post again as you always have as you have a need to get the last word in. Panther who started this now epic Hugh babble thanked me for basic knowledge and you just spew things you feel make you superior. Sorry Panther.
Mic

[eXoNerated]

I wont go there with you Mic it's nothing "personal" . Just talking about the props buddy is all.

Regards,
Hubert

[HTVboats]

[Ch.Lucas]

Hi Mic,
thanks for you wise words, we know from IW .
@Panther6834,
i try to bring some understanding into the context. But it doesn't necessarily have to be that way, I don't know your boat and not all components of the drive.
The smaller two-bladed propeller that has the same slope as the slightly larger three-bladed propeller can make the boat faster for the following reason. The small propeller puts less strain on the engine and therefore the speed will be higher. Even with the smaller two-bladed propeller, the higher speed can pass through the same amount of water as the larger but lower-rotating three-bladed propeller. The thrust would be about the same. If the boat is still running in a speed range in which the resistance is not very high, then the higher speed can be converted into a higher top speed with the same gradient. The braking effect of the boat does not seem to brake so that there is no more speed increase. This is actually a very good sign for the boat as it also converts small but faster propeller flow into speed. In the oval race, however, the three-bladed propeller can accelerate out of the curve better due to its additional propeller blade and thus arrive at the next bend a few feet before the two-bladed propeller. Do you still know Ed Fischer's Circus Circus Cannard? That was e.g. a boat that did not drive the highest speed on a straight line for a long time, but in the curves the boat has first been driven around the buoys on the inside and has lost little speed. This led to the fact that it was almost unbeatable at the RC racing boat races and was only taken out of the races by exile. You just have to experience and test and test these things, you can't get around. As Mic wrote, even small changes to the propeller themselves make very big differences in what makes lift, thrust, propwalk and smoothness. It doesn't help if you have installed the best propeller according to the latest knowledge of fluid dynamics on the boat, but then the boat jumps around like a billy goat and cannot build a proper thrust at all. Then there is the knowledge of experienced boaters who then make the boat more drivable and faster. You have to work hard to achieve that. The cupping of the propeller blades accelerates the current at the tear-off edge and makes the propeller reach faster in the water, usually you get a better acceleration of the boat. If you give the propeller blades a little cupp on the outside, i.e. on the cutting edge almost entirely on the outside, the boat is reduced in the lift and it does not jump with the stern.

Happy Amps Christian

[Ch.Lucas]

Hi Panther6834,
one more thing . I often just stood by the sink in the kitchen and turned on the tap, so a strong jet of water comes out. Then I took a piece of aluminum sheet and held it in the beam and then used pliers or a hammer and various steel balls or other rounded solid steel parts to bend in various curves. The cutting edges are ground and bent and so on. You can clearly feel with your hand what creates a little more distraction and what doesn't work so well. Simply hold a normal spoon in the water jet. The outside does not exert much force and thus directs the beam around the curve, which is simply not a good thing. The hollow spoon side, on the other hand, generates a lot of distraction force and you can deflect and steer the water jet much more violently than with the outside. Everyone has certainly played it that way somehow. But if you take a closer look and observe what the water does, these are very important findings that help you a lot in improving the drives and the boat itself. Tomorrow I'll take a picture of the tread of one of my 1:12 hydroplanes that won some races, although I didn't always have the batteries with the highest energy content. The boat just runs quite easily.
Happy Amps Christian

[Panther6834]

Panther6834,
i try to bring some understanding into the context. But it doesn't necessarily have to be that way, I don't know your boat and not all components of the drive. he smaller two-bladed propeller that has the same slope as the slightly larger three-bladed propeller can make the boat faster for the following reason. The small propeller puts less strain on the engine and therefore the speed will be higher. Even with the smaller two-bladed propeller, the higher speed can pass through the same amount of water as the larger but lower-rotating three-bladed propeller. The thrust would be about the same.

If the boat is still running in a speed range in which the resistance is not very high, then the higher speed can be converted into a higher top speed with the same gradient. The braking effect of the boat does not seem to brake so that there is no more speed increase. This is actually a very good sign for the boat as it also converts small but faster propeller flow into speed. In the oval race, however, the three-bladed propeller can accelerate out of the curve better due to its additional propeller blade and thus arrive at the next bend a few feet before the two-bladed propeller.

Happy Amps Christian

Thanks for the info...definitely helpful (again, for me, as well as for others in need off this type of info).

Since you mentioned it, and worded it in such a way as to appear actually interested in knowing, here's my current lineup:

Atomik Barbwire 3 (upgraded to Seaking 60A ESC & Dynamite 8-Pole 2950kV outrunner motor, on 3S)
ProBoat ShockWave (my "rescue boat", so no need to change props)
ProBoat SonicWake (currently running stock electronics, but soon to be running Seaking 180A ESC & Leopard 3674 1400kV motor, on 6S)
ProMarine Skater X2 (dual Seaking 120A ESCs & ProMarine 3674 2075kV motors, on dual 4S) - for NAMBA P-open
TFL Pursuit carbon fiber (Seaking 180A ESC & SSS 3656 6-Pole 2030kV motor, on 4S) for NAMBA P-Open

You'll probably notice that the SonicWake's "upgrade" motor is actually less than the stock motor. I'm currently running the stock motor on 4S...but, in swapping the ESC & motor, and moving up to 6S, I'm not trying to make the boat faster - I'm trying to make it run cooler (meaning, the electronics), and give it a longer run time. If it happens to be faster (than the stock electronics on 4S), that's a 'bonus'...but, it's not a "requirement".

No later than next March, I also plan on adding a TFL Zonda to the collection, although I'm still debating which version to get: the fiberglass, the all-carbon fiber, or the carbon/Kevlar. This one probably wouldn't be for racing, as the only class (as far as I'm aware) it qualifies for is is S-SAW, which they don't run in District 9 (again, as far as I'm aware). Whether sometime this year, or sometime after getting the Zonda, I'd also like to add a race-capable hydro to the lineup...although, I haven't yet decided if it will be a commercially-available boat (such as the ProBoat UL-19), or something custom-built for me.


~ More peace, love, laughter, & kindness would make the world a MUCH better place

[1coopgt]

I also plan on adding a TFL Zonda to the collection, although I'm still debating which version to get: the fiberglass, the all-carbon fiber, or the carbon/Kevlar. This one probably wouldn't be for racing, as the only class (as far as I'm aware) it qualifies for is is S-SAW, which they don't run in District 9 (again, as far as I'm aware). Whether sometime this year, or sometime after getting the Zonda, I'd also like to add a race-capable hydro to the lineup...although, I haven't yet decided if it will be a commercially-available boat (such as the ProBoat UL-19), or something custom-built for me.


~ More peace, love, laughter, & kindness would make the world a MUCH better place

After watching MRMAD2424 hit 111mph with a stock(other than Dasboata Props) fibergass TFL Zonda I decided to add one to my collection. Now I wait. What stinks is there isn't a lot of info on this boat in the forums. It's been out since 2013. You would think there would be all kinds of information in the forums about this boat .

Sorry for the subject change/ highjacking . I couldn't resist when I saw you were thinking about a Zonda. I'm also building a 1/8th scale Hydro.

[eXoNerated]

@ Lucas the persistent troll who's every thread gets banned in Germany.

There's no wise word from IW just more of your gang violence and silly unfinished projects and dead end threads. Will you be a man stop lying and grow up? These papers I looked up at university of Florida here in the USA. What one you author All you did is showed me a 5j profile in a page in a book online. That post can be brought in but I don't care really I just wish you'd get off the sunk sofa in Bayern and stop harassing F3S pilots in Germany and me here in the USA. You turned out to be a real enigma. Jim showed me things u never did and you spoke on what you knew but I sought a million times more information on my own than any man has ever taught me PERIOD u can keep talking but you aint saying a thing true. That's why the most recent literature on super cavitating props went from me to you. I don't know why you keep bringing up Jim you met him thru me. He has nothing to say and cares less about this or you. And why would I need you or any other man to do my own trig? Get lost your trolling hard. If you have so much time complete a project and stop playing in the pool. Jim will tell me anything I wanna know anytime and you are not really his friend . You are very immature and hadn't run a boat in 30 years. Jim like me has logged time on the water in this millennia when will you? Jags was right you are a "F-wit". Jim Schaefer and I have shared many emails over the years. You have a special power and know what people you never met in your life do. Its freaking amazing. You must sit in my pocket, a portable bobble head, so insecure about yourself you have to sit here and lie online. ABC saw no need for a 5 Johnson profile to run SAW. The one you learned out of a book just like me. That's how far that help went and is applied to any boat I have. Zero it's Mystic! Apply it to your own boat this year why don't you. I maintain 2 million dollars worth of 7 axis fanuc paint robots with estat paint applicators for Mercedes Benz as well as a 1/4 of the entire plants automation line BY MYSELF. These robots paint 153 buses and travel on the 7th axis rack 10 kilo meters every three days I DON'T NEED U YOU FOR S*%T and never did you need to get that clear Gibroni! MAKE A WAY BACK TO BAVARIA!

Transfer efficiency improvements, Day tank automation commission, waste recovery refinements. Positive displacement pump rebuilding. I'm the spearhead pimp! When you hire me? And when you teach me this? NEXT YEAR when I HIT E3 I WONT HAVE TO PAY FOR MY GT OR THE GAS!

Christ, GET A LIFE!
Hubert

[eXoNerated]

What are the moderators going to do ? Hes been braking the rules for awhile now and you can see that I've clearly tried to maintain a sense of civility and even left his thread totally alone, but this old ass fool in Germany who thinks hes graduating genius men in the US is really staring to get on my damn nerves! I don't know what educational value the forum finds in his bs ad hominem but I don't find any in it. Whens it stop?


Regards
Hubert
IMPBA 20779S

[Panther6834]

What are the moderators going to do ?

Say what you will, but Lucas is one of only two people who've commented with something that actually makes sense (the other person knows who he is, as I PMd him directly)...and, you are, most definitely, NOT one of the two I'm referring to. You drone on & on, without ever saying anything meaningful. You've spouted off a bunch of double-talk, workout ever saying anything of importance that's truly relevant to the queries I posted. I never asked for "empirical evidence", or any scientific proof. If you had even the most minute ability to comprehend what I was inquiring about, you would have realized I was strictly talking about REAL-WORLD use. Your comments have been disruptive...and, quite honestly, have been a waste of space.


~ More peace, love, laughter, & kindness would make the world a MUCH better place