Florida Boat man here, again. The Step hull Is Great for rough water, but ultimately slows you down. They're basically hooks. To achieve better performance you need Trim and Tilt, and Jack Plates. The trim and tilt will allow you to adjust the angle of thrust, making it easier to get on plane and reach a top speed. The jack plate will give you control over the depth of the engines, which also helps with acceleration and speed. Prop pitch Is super Important, but I'm not sure how that would translate into miniature applications, so you're sort of at a loss there. And finally, you made a very good observation not too many people would catch. The engines on the outside will get thrashed without something to help break the water. This is true for large applications as well. They're dragging more than providing thrust at that point. The ORIGINAL idea behind Multiple engines was to avoid getting stranded. If an engine failed, the remaining engines would provide enough power to pick the boat up and put it on plane. There's nothing worse than having to chug along at 5mph, 100 miles offshore, because you cant get on plane and cant risk burning all the fuel by plowing through the waves. Any number of engines past that is normally just a rich dude flaunting his cash and ego. And just for fun, I bet the hull you chose to model your "12 AM Quickee," after is either a Intrepid or a Contender (32'+ IRL)
I think he was also hitting the problem of not having enough weight in the nose.. The stack of three rows was definitely working though - so fast. All it needed was full all engine steer and that extra bit of weight..
*SOLUTION: You need a single toy boat mounted **_BEHIND_** the outboards but inline with original ship hull. With the three rows of motors only the first row is getting clean undisturbed water, everything behind it is just causing drag.*
You can get way more speed just by changing props. For the four motor set up the props are probably perfect for the power you have, but with the 12 motor setup you have tons of power you aren’t using. You can see this by the fact that the boat had an almost nonexistent 0 to top speed time. You need steeper pitched props to utilize all that power. For reference look at offshore race boat props. That’s probably the level of pitch you need. Where they are almost parallel to the direction of boat travel through the water. You could even do sequential pitch on each set of 4 motors. The ones closest to the boat being the shallowest pitch and the third set back being the steepest. You could definitely do a revisit video testing prop pitch.
It's the reason the ridiculous photoshop's even exist. It's because that is the actual mentality of Americans building/buying these boats. I even tried my hand at a silly photoshop like this one time.
I feel like the correct answer is that once you need more then 2, you probably need to consider inboard engines. 4 or more and you're kinda just showing off that you're a wealthy idiot.
Hey Peter, if you want the boat to be able to turn in the stacked rows of 4, you'll need to invert the direction of the second set of motors. Having multiple pulling in the same direction will result in a "crab walk" or "strafe". / = crab walk / = turn / \
With the addition of the smaller side boats, you created tons more drag. Also, the motors in rows wasn't effective because you wont go any faster without an increase in rpm, which would increase the drag from the slower motors. An impeller setup would be fun to watch!
Also the reduction in propulsion due to neighboring propeller wake causing cavitation interruptions and blades being out of water. Watercraft are several separate systems designed to work together; hulls, propulsion, etc. You just can't tack a random drive system on a sail boat, barge, or anything random that floats and expect performance or worthiness.
I am fairly confident peter knew exactly how this video would turn out to be even before doing all of this. Its just fun to go through the process even still :)
@@godsonjosephI find physical models help a lot when I comes to seeing what other options might work. Kinda like the turbo axle. What an innovative technique that flopped hard. I’ve always wanted to see it revisited with more modern tech. Plus some odd things are just cool. The rotary Motor has its mighty big list of downfalls but it’s such a cool system to see done well.
the prop pitch dictates the max speed. No mater how many motors you add, it will always reach the same max speed. You need to increase the pitch together with adding motors to gain more speed. Anyway, thanks for another hilarious project!
I pretty much had an idea about the outcome from the start, you guys confirmed it. It's not just the number that matters. There are fluid dynamics at play. That said you just need bigger faster motors, not more of them. Besides more =more headaches and maintenance
I like the attention to the little details, like the rotating radar on top. The original row of motors might done better if there was adjustable trim. Also more might be more beneficial to run at top speed even if towing a skier.
You have a planing hull, with lifting strakes and all the weight is at the rear which does not permit the lifting strakes to 'lift' the boat. Add some weight to the front and it may fix the issue, and will also reduce your rear drag.
How about glueing one of those spare outboards to the back of the boat, pointing straight down, to help lift the boat out of the water? It looks like a lot of the energy created by those 12 outboards was wasted in pushing the bow of the boat upwards....
I love this idea. From what I can tell, the motors on riggers was just too much, and putting them in rows behind might work if you make the propshafts longer on the motors the further back they are. Also the props are possibly too small since there is a bunch of bubbles from cavitation, but first try putting the props deeper in the water the further back they are and if you still see lots of aeration behind the boat when its not on plane, increase prop diameter and or pitch.
I agreed with the boat show guys "never enough motors" until you sent it...its be col to see some different prop configurations as well...and oh yeah you need to make it fly :)
For the amount of propulsion/engines you're wanting to use, the draft & water displacement is too shallow (or you need to switch to a more flat bottom, plane hull and/or a hydro-foil.) Increased surface area & buoyancy wasn't the solution, but increased ballast, changing the center point, and a longer, prouder keel. Your hull is the problem for the power you want to output - that hull will always turn submersible at excess speeds.
More engines give you more torque but not necessarily more speed. More speed would come with different props or faster prop speed. Also putting more weight on the front to balance out the boat better might allow it to get up on plane easier.
@@nielsdebakker3283 OK.... That confirms what I just commented elsewhere then... I felt like 2 is the sensible number, and if you need more, you probably want to consider inboard instead. I'd say 3 is the max you'd ever want outboard, and 4 or more is just showing you're a wealthy idiot.
Your prop pitch is basically your gear ratio... If you keep the same gear ratio and add more motors, it'll get to top speed quicker but will not go faster... Of you add more motors (more horsepower) you'll need to increase your prop pitch to give it a higher gear ratio which will give you more speed.
I'd be curious, whether cutting some holes in the middle of the boat and fitting more motors through there might solve things. Presumably, the water will no longer be as turbulent once it reaches the motors at the back, so it might function better than the stacked rows. Also, you could fit the propellers in the middle somewhat lower than those at the back to get the boat to naturally pitch upward a bit.
I just wanna point out an interesting thing the motors on the right side of the boat when you lined them up on both sides were making the down wash much less frothy that's normally a good indication that efficiency is going up. I know in planes they had some success with tip motors making a vorticy that helps drag. Might want to try making them turn the other way on the left side and making new props.
You just create more torque if you don't change the propellers. That's why it doesn't go any faster. Also adding counter-rotating props could be ideal for the stacked setup.
My thought on this is that more same motor is like connecting the engine with more wheels to spin, like fwd vs AWD. I'd say there is a slight improvement in initial acceleration. At the end of the day, you are reaching the top flow speed of the rotors.
Your always going to be up against the 'hull speed' of a boat, adding more motors just adds more drag once you go past the happy balance of power for the hull design
That's what I was taught by a sailor. He was training me on a sailing yacht. He said, while under motor power, don't push the RPMs past the point of diminishing returns. The hull speed maxes out, and more power just uses more fuel without much, if any more speed. This guy's hull seemed maxed out, and more motors just made more bubbles, not speed. He's gotta deal with drag as he adds more power.
That one boat in the intro had 6 of the 600 horse Verado motors....$77,000 each!!!!! That is just insane. The model engines here are SO cool! What a great use for 3D printing!!
Its like a Midnight Express, dude it is. I want that hull! Looks awesome. Oh, and I love the "Little" Johnson on the outboard cover. lol Great Job Peter!
I love the attention to detail, especially on the "little johnson 25" stickers. I grew up with a small johnson 15 outboard that looks just like the ones you made.
9:40 Yeah the issue is thrust basically your creating a vacuum under the hull causing it to stick to the water and drag down the rear end theres a couple ways to fix this one of the simplest however is extending the length so it takes more force to leverage it down or weights at the front
A propeller in water pushes water backwards, propelling the boat forward. The terminal velocity of the boat is the velocity of that backwards stream of water minus the drag of the boat. The more propellers in the water, the less effect the hulk drag has on decreasing that terminal velocity, but at some point you can only go as fast as the propeller spins and sends the water backwards. Basically the more motors you have the better at towing you will be at low speeds, but it won’t ever make you faster than the terminal velocity of a single engine propulsion stream … It’s like a car with tires that slip on the road surface. Making the tires wider will get you better grip, but won’t make you go faster..
@@PeterSripol any chance you have the stl files for the console and hard top?? I have been searching the internet with no luck. Just want to print a cool display model.
bro, look at the Viet Nam era PTR (Patrol boat, river). It had a two stage impeller and was SO fast for its size. I think it was probably converging on the limit of the maximum velocity of a traditionally hulled boat. Could be very cool to try on the RC scale... Especially as a test to model up for your new large boat....
The boat is already going at it's top speed with 4 motors on it. Adding more motors will not change the top speed. It'll just change how fast it gets to top speed. You could probably double the speed just by changing the pitch of the props on the 4 motor setup
0:10 - Just a friendly bit of advice... i would stay away from red, blue, and other bright colored drinks before/during you film. I have seen your other videos and nothing looked strange, but this one kept me glacing at your red teeth - no doubt temporary and from the drink - it still pulled attention away from the awesome content you put out. Outside of that, im glad i found the channel - i have been big into RC going back 20 years before drones, multi-access gyros, and even before decent ESC/Brushless motors when nitro helis ruled the competitive scene. Hope to see you at IRCHA some year, just as good as flight-fest but a bit more heli/quad oriented compared to the Flight Test crowd.
As noted by others here, there are a number of other factors that affect the performance that seem to be lacking proper consideration on this model boat: prop pitch and diameter, motor attitude (tilt/trim) and balance of the load--I can assure you that the boat will perform much better if those batteries are moved further forward, and that will decrease any need for additional lift at the stern (such as the empty plastic drink bottles or those smaller hulls), whether it's on a radio controlled model or the real thing--too much weight in the back and it's hard to get it to plane, the stern wants to drop down into the water, and your videos prove that--the extra width can also be a problem, but so can additional length--there is always going to be a point of diminishing returns, so YES, there can be such a thing as "too many" outboard motors--it was still a hoot to see all of the modifications and test runs, thanks for the laughs--
another issue you ended up running into was weight bias and trimming. with the weight in the rear it needed more trim down, or weight up front to balance out.
Great stuff!! Props in the 2nd and 3rd row cavitate and provide no thrust once the boat gets going; they just suck air from the props in the first row.
I'm pretty sure one optimally shaped and high powered prop is the most efficient, maybe two props rotating opposite directions to cancel out rotational torque. Using more than two IRL is more for compromise reasons than to be opttimal; e.g. more small propellers rather than one or two big ones to be able to go into shallower harbours; more props in pods around the ship to get more maneuverability at the cost of less optimal max speed, multiple outboards on a smaller boat to get around size limitations (both physical and legal maybe) of how large an outboard can be before it's impractical; or just because you want more power than the largest outboard that is made etc. (and for some reason you want the motor to be outboard). Outboard engines is already in itself a compromise; by having the engine and propeller combined as one unit you make it easier to add and remove the engine to the boat, and originally most people would detatch the motor and gas tank and keep it at home most of the time and only leave the boat outdoors or in the marina. But with the ridiculously large outboards, and particularly a complex multi engine steering setup it's a huge process to add and remove the engines anyway, so they might as well be inboard engines; but I guess some boys like to brag about how massive and how many engines they have and it's easier for everyone to see how excessive your setup is, if it's all outboards...
FYI; a Mercury 450R costs between $55,000 and $80,000 each, Each engine will consume 2 litres of petrol every kilometre at speeds over 25 kmh. So, six of them will use 12-litres per klick. In NZ, that would cost $34 per kilometre, for the fuel alone!
To me as a mechanical engineer the best solution was the first solution(all engines next to eachother). In your experiment due to the fact adding more weight to the back and the torque of the engines it didnt work as well as it could have. I think you should add more weight to the nose of the boat. this will result in better performance up until a certain point. Putting engines in front of another one will not result in an increase of power due to flow interferance of the engine in front. For the mentioned first setup: adding engines will work for increased acceleration(in my theory). however, top speed wise it wil not likely increase up until a certain point as the propellers of the engines will simply not turn faster then a certain rpm(adding 2 engines from 16-18 engines for example will not be likely to increase much top speed).
the problem you were having getting on plane wasn't the motor configuration as much as the motor "pitch". to get a boat on plane you have to trim the motors up so they try to thrust slightly downward which in turn lifts the nose of the boat and gets more of the hull out of the water so you go faster with less resistance.
you could also put the motors behind the boat but in a stair arrangement so that the turbulence from the motors closest to the boat doesn’t affect the other motors
Peter: Hull is what determines maximum speed, not the size of the motor. At a certain point the resistance of the hull on the water becomes maximum and no amount of added horsepower will make you go faster. instead: the excess pressure in the transom causes it to break the motor mount.
I love the thought and the execution, but i have some thoughts as well. with all the engines, as you said, adding them in a "series" manner does not increase the effect as much as side by side as there are props functioning on turbulent flow with a lot of cavitation (air bubbles created by unnder pressure for those unknown :) ). My immediate hypothesis is that when using more engines, the torque needed by each motor decreases, meaning you could increase the prop pitch to push more water pr. rpm, increasing the top speed. If the maximum rpm is reached, but the engine is "running loose" (definitian ad hoc now: push
Adding 3 more outboards, but not right behind the others... might be a bit better then 4x3 config. And turning on off the motors based on left/right would help turn
i think the motors set up at 12:30 would be a great idea if you raise them up as you ad rows on behind because with them the same height as the row in front of them when you take off buries the whole motor under the water and the water hits the big part of the motor and cancels out the water flow if they were raised then they wouldn't interrupt the flow of water so much and would help speed up the flow
A triangular transom might keep six to eight motors inside the critical footprint without overlapping cavitation. It's having hull in front of, or over the prop that stops the thrust burying the rear. It should work with the correct trimming to compensate but it would need to be dynamic with each motor adjusting its AOA in accordance to the trust torque .
I think that the main contributing factor to the top speed of the boat is how fast the motors themselves are spinning. To put it in a different example, lets say you have an RC car with a motor on each of the wheels. If the top speed of the motors will only push the RC car to 10mph, then it doesn't matter if you have 2, 4, 12, or 20 wheels driving it forward, the top speed will still only be 10mph. That is essentially what you have here. Having more motors that are also pushing at the same speed isn't going to make it go any faster. It might have more thrust, but that thrust still has a top speed. That said, the correct number of outboards = the least number of outboards it takes to give it the maximum amount of acceleration and top speed. If you can do it with less motors, than it's more efficient.
This kind of setup is usually used for boats that transport illegal substances over the sea. The only limit is fuel efficiency and the police boats (they have to be faster than a police boat).
More weight in the front will definitely help. I have a john boat that can only get on plane with 4 people if 3 of them are all the way at the front. Even if you added weight that wasn't there yet it may help
You came to the right conclusion about the motors. You didn't try adding ballast to the bow of the boat to keep the bow down and help it get on plane better. Doing this should help to reduce drag and increase speed. There is a fine line between balance and nose dive, have fun.
Correct number of Outboards is what your boat transom tells you you can put on it which is normally in horsepower. I watched a fellow get a hard bottom inflatable boat which was rated for a two horse power motor and he put on a three and a half horse power motor because he said that number that was on the transom was just a suggestion which is not very smart of him. Eventually he might start having issues with his transom breaking or bending or cracking because of the extra weight. Always go by the manufacturer's recommendation
so glad you tried all the configurations and went 12x maybe a prop swap for the successive layers of motors like each row gets more agressive pitch props basically each row being a stage ... uh oh you forgot to do single file 12x outboards can't wait to see 🙈 the results ❤
Why not mount fore to aft Hull, so they are like "Bow" Thrusters, spacing them out under hull, staging port & Starboard there layout so they don't interfere with each others "wash" ... or just go with 2 ducted Fans (EDF's) on rear to push water ... ;)
If you wanna have more motors behind one and a other they need to rotate differently for it to have a effect And to boost this kind effect to the max the turbines need to be inside a tube So small explanation the one in front rotates left and the one in the beck rotates right and tada more speed this concept is used in some wind tunnels btw
I think you should have two long arms at the front with an air foil connecting between them with motors mounted on it... The air foil should be lower than the rear motors...
Some of these configuration I wonder how much you were limited by prop pitch and hitting pitch speed with the boat (speed where your prop has no slippage and theoretical max speed of a certain pitch/rpm combo)
You could have used toroidal propellers to reduce sound and increase efficiency. Its possible to print but bit more hard since its a complex shape in such size.
Got to change the pitch on the props to increase speed. Example, 5000 rpms at 12 inches (pitch of prop) of travel per revolution is a constant no matter how many horse power you have. 5000 rpms at 24 inches (pitch of prop) of travel is twice as fast. More horsepower (more motors) allows you to reach the 5000 RPMs at a higher 24 inch prop pitch
In addition to being in turbulent wake, realistically the props can only get the water up to some speed V_max. If the water a prop is ingesting is already near V_max, it's not going to make a huge difference in the speed of that water and thus the thrust produced is going to be marginal at best. At the end of the day the force you can produce is going to be the difference between momentum of the water in vs momentum of the water out. If there's a small difference in momentum, there's only a small difference in force.
The first outboard config was the best. Bring the nose down and your motors will work. Your fore is lifted too much with the aft propulsion and weight. Moving ballast to the front or a downturn hydrofoil to direct the fore down. I also think a hydroplane version of this would be pretty sick The in-line config interferes too much with the prop and rudder efficacy. Too many bubbles and not enough water to grab. A single row perpendicular to the keel is optimum rather than stacked, Moderate adjustments may be needed for the rudder config
I'm amazed how well the low camera angles make it look like a full size boat!
Agreed lol 😅😂
Was thinking the same thing!
@Karl with a K ?
@Karl with a K shut up carl
Agreed. The thumbnail got me until I started the video. But I'm drunk so it might not count.
Florida Boat man here, again. The Step hull Is Great for rough water, but ultimately slows you down. They're basically hooks. To achieve better performance you need Trim and Tilt, and Jack Plates. The trim and tilt will allow you to adjust the angle of thrust, making it easier to get on plane and reach a top speed. The jack plate will give you control over the depth of the engines, which also helps with acceleration and speed. Prop pitch Is super Important, but I'm not sure how that would translate into miniature applications, so you're sort of at a loss there. And finally, you made a very good observation not too many people would catch. The engines on the outside will get thrashed without something to help break the water. This is true for large applications as well. They're dragging more than providing thrust at that point. The ORIGINAL idea behind Multiple engines was to avoid getting stranded. If an engine failed, the remaining engines would provide enough power to pick the boat up and put it on plane. There's nothing worse than having to chug along at 5mph, 100 miles offshore, because you cant get on plane and cant risk burning all the fuel by plowing through the waves. Any number of engines past that is normally just a rich dude flaunting his cash and ego. And just for fun, I bet the hull you chose to model your "12 AM Quickee," after is either a Intrepid or a Contender (32'+ IRL)
Most definitely a contender
Just read Florida and he's qualified from the start and expert 🦅🇺🇸
thank god were moving to pensylvania this summer been stuck here in florida for 7 years! (that was just bad luck i can speel)
@@josephgraham3807 Pensylvania? Get a rope!
I think he was also hitting the problem of not having enough weight in the nose.. The stack of three rows was definitely working though - so fast. All it needed was full all engine steer and that extra bit of weight..
This channel is like _Tool Time_ with an insane amount of imagination and energy.
More power!! (Tim allen grunt noise)
If peter uses the boat to smuggle cocaine it would be perfect
Ahh the Binford Bad Boy Boat.
AEUHHH???
*SOLUTION: You need a single toy boat mounted **_BEHIND_** the outboards but inline with original ship hull. With the three rows of motors only the first row is getting clean undisturbed water, everything behind it is just causing drag.*
You can get way more speed just by changing props. For the four motor set up the props are probably perfect for the power you have, but with the 12 motor setup you have tons of power you aren’t using. You can see this by the fact that the boat had an almost nonexistent 0 to top speed time. You need steeper pitched props to utilize all that power. For reference look at offshore race boat props. That’s probably the level of pitch you need. Where they are almost parallel to the direction of boat travel through the water. You could even do sequential pitch on each set of 4 motors. The ones closest to the boat being the shallowest pitch and the third set back being the steepest. You could definitely do a revisit video testing prop pitch.
I love how everyone at the actual boat show was like “yeah never enough outboards”
That was funny. needs more
They were being nice and having fun.
It's the reason the ridiculous photoshop's even exist. It's because that is the actual mentality of Americans building/buying these boats. I even tried my hand at a silly photoshop like this one time.
I feel like the correct answer is that once you need more then 2, you probably need to consider inboard engines. 4 or more and you're kinda just showing off that you're a wealthy idiot.
Hey Peter, if you want the boat to be able to turn in the stacked rows of 4, you'll need to invert the direction of the second set of motors. Having multiple pulling in the same direction will result in a "crab walk" or "strafe".
/ = crab walk / = turn
/ \
I would be surprised if he wasn't aware of this since this is also true for planes with twin props or more.
@@FtanmoOfEtheirys you misunderstand, he means the steering direction not the prop rotation direction. airplanes do not steer the prop.
@@bigiron4018 Thanks
@@FtanmoOfEtheirys Also, misunderstanding or not, knowing something and thinking to do something are two very different things.
Although I did just realize only the first set of motors turns, hence the issue.
Ok, I really want to see 1:30 done with a full size outboard now lol
The baby outboards are so cute!
With the addition of the smaller side boats, you created tons more drag. Also, the motors in rows wasn't effective because you wont go any faster without an increase in rpm, which would increase the drag from the slower motors. An impeller setup would be fun to watch!
Also the reduction in propulsion due to neighboring propeller wake causing cavitation interruptions and blades being out of water. Watercraft are several separate systems designed to work together; hulls, propulsion, etc. You just can't tack a random drive system on a sail boat, barge, or anything random that floats and expect performance or worthiness.
13:38 covered this...
I am fairly confident peter knew exactly how this video would turn out to be even before doing all of this. Its just fun to go through the process even still :)
@@godsonjosephI find physical models help a lot when I comes to seeing what other options might work. Kinda like the turbo axle. What an innovative technique that flopped hard. I’ve always wanted to see it revisited with more modern tech. Plus some odd things are just cool. The rotary Motor has its mighty big list of downfalls but it’s such a cool system to see done well.
Hydrodinamics failed him here
the prop pitch dictates the max speed. No mater how many motors you add, it will always reach the same max speed. You need to increase the pitch together with adding motors to gain more speed. Anyway, thanks for another hilarious project!
I pretty much had an idea about the outcome from the start, you guys confirmed it. It's not just the number that matters. There are fluid dynamics at play. That said you just need bigger faster motors, not more of them. Besides more =more headaches and maintenance
Nowadays such real life boats are using toroidal props for propelling themselves they're quite efficient too
I like the attention to the little details, like the rotating radar on top.
The original row of motors might done better if there was adjustable trim.
Also more might be more beneficial to run at top speed even if towing a skier.
You have a planing hull, with lifting strakes and all the weight is at the rear which does not permit the lifting strakes to 'lift' the boat. Add some weight to the front and it may fix the issue, and will also reduce your rear drag.
Good idea. I was thinking about weight too when it wasn't working well also.
Exactly this👌
Trim the motors down a little maybe ?
It is a ballast and center point issue, but I believe that specific hull will always plow-under and turn sub at an excessive speed point.
How about glueing one of those spare outboards to the back of the boat, pointing straight down, to help lift the boat out of the water? It looks like a lot of the energy created by those 12 outboards was wasted in pushing the bow of the boat upwards....
I love this idea. From what I can tell, the motors on riggers was just too much, and putting them in rows behind might work if you make the propshafts longer on the motors the further back they are. Also the props are possibly too small since there is a bunch of bubbles from cavitation, but first try putting the props deeper in the water the further back they are and if you still see lots of aeration behind the boat when its not on plane, increase prop diameter and or pitch.
I agreed with the boat show guys "never enough motors" until you sent it...its be col to see some different prop configurations as well...and oh yeah you need to make it fly :)
Hydrofoil it!
I like sailing, I think ONE engine is one too many xD
@@power21100 hydrofoil...to float plane takeoff.
For the amount of propulsion/engines you're wanting to use, the draft & water displacement is too shallow (or you need to switch to a more flat bottom, plane hull and/or a hydro-foil.) Increased surface area & buoyancy wasn't the solution, but increased ballast, changing the center point, and a longer, prouder keel. Your hull is the problem for the power you want to output - that hull will always turn submersible at excess speeds.
I was waaaay to happy to just keep watching B-Roll of the 4 motor setup. I am so easily entertained......
More engines give you more torque but not necessarily more speed. More speed would come with different props or faster prop speed. Also putting more weight on the front to balance out the boat better might allow it to get up on plane easier.
More outboards also means more drag. A pair of big outboards for a certain powerlevel is more efficient than more smaller ones.
@@nielsdebakker3283
OK.... That confirms what I just commented elsewhere then...
I felt like 2 is the sensible number, and if you need more, you probably want to consider inboard instead.
I'd say 3 is the max you'd ever want outboard, and 4 or more is just showing you're a wealthy idiot.
Your prop pitch is basically your gear ratio... If you keep the same gear ratio and add more motors, it'll get to top speed quicker but will not go faster... Of you add more motors (more horsepower) you'll need to increase your prop pitch to give it a higher gear ratio which will give you more speed.
I'd be curious, whether cutting some holes in the middle of the boat and fitting more motors through there might solve things. Presumably, the water will no longer be as turbulent once it reaches the motors at the back, so it might function better than the stacked rows. Also, you could fit the propellers in the middle somewhat lower than those at the back to get the boat to naturally pitch upward a bit.
I just wanna point out an interesting thing the motors on the right side of the boat when you lined them up on both sides were making the down wash much less frothy that's normally a good indication that efficiency is going up. I know in planes they had some success with tip motors making a vorticy that helps drag. Might want to try making them turn the other way on the left side and making new props.
what if u use real boat engines
He’d be even more broke😂
frfr
And TV wonders why their ratings are down. Channels like this are the new entertainment! Cheers!
You just create more torque if you don't change the propellers. That's why it doesn't go any faster. Also adding counter-rotating props could be ideal for the stacked setup.
My thought on this is that more same motor is like connecting the engine with more wheels to spin, like fwd vs AWD. I'd say there is a slight improvement in initial acceleration. At the end of the day, you are reaching the top flow speed of the rotors.
Very close too if not reached.. I think you have the real answer here.. Need faster propellers.
I love how the consensus of the boat show was "never enough motors"😂
5:17 that 80s montage is sick, spectacular work yet again
The lil spinning radar is the cherry on top 🤌
You should have Tried Counter Weight
Your always going to be up against the 'hull speed' of a boat, adding more motors just adds more drag once you go past the happy balance of power for the hull design
you're
@h2s142 hey man, I'm just doing my job to help fight the "your you're there their they're our are" pandemic.
That's what I was taught by a sailor. He was training me on a sailing yacht. He said, while under motor power, don't push the RPMs past the point of diminishing returns. The hull speed maxes out, and more power just uses more fuel without much, if any more speed. This guy's hull seemed maxed out, and more motors just made more bubbles, not speed. He's gotta deal with drag as he adds more power.
Peter: drops 3D printed outboard in fishtank
Fishes: "ahhh noooo... not again !"
The fish looks sad enough in that tank already
@@markchinguz4401 Yeah, straight up r/shittyaquariums material.
yeah, wtaf, animal abuse right there
so this is how to turn a 12 AM quickie into an orgy, btw, if you want it to go faster with more motors increase the pitch of the props.
would love to see more along this idea, like dedicated turning props, and submarines!
you could also 3d print internal channels and make jets!
@@PabloEdvardo Subs that can fly it is!
That one boat in the intro had 6 of the 600 horse Verado motors....$77,000 each!!!!! That is just insane. The model engines here are SO cool! What a great use for 3D printing!!
Its like a Midnight Express, dude it is. I want that hull! Looks awesome. Oh, and I love the "Little" Johnson on the outboard cover. lol Great Job Peter!
I lost it when I read "12am quickie"
I don't know how easy it would be but you should make an rc gatortail surface drive
Government: oh no! We must regulate that!!
Damn!😂
i love the little garmin GPS thing on the top spining its so cool to see all these parts work.
I think my favorite thing about this and many of Peter's videos is the chemistry between him and his brother.
Pitching the motors will give you more speed, plus counter rotating motors might be helpful too.
Hi Peter love your videos. You should make a dermal boat.
SKINBARGE
Oh, you meant Dremel!
I love the attention to detail, especially on the "little johnson 25" stickers. I grew up with a small johnson 15 outboard that looks just like the ones you made.
buy mini tug boat hibda 15 hp 21 moh 18 inch draft dowñ
Support from Philippines 💪☝️
9:40 Yeah the issue is thrust basically your creating a vacuum under the hull causing it to stick to the water and drag down the rear end theres a couple ways to fix this one of the simplest however is extending the length so it takes more force to leverage it down or weights at the front
great to know i'm not the only one who thinks they put way to many on there
I mean.. in my opinion once you go over.. 3 it's already stupid, but if they have the money... idk
A propeller in water pushes water backwards, propelling the boat forward. The terminal velocity of the boat is the velocity of that backwards stream of water minus the drag of the boat. The more propellers in the water, the less effect the hulk drag has on decreasing that terminal velocity, but at some point you can only go as fast as the propeller spins and sends the water backwards. Basically the more motors you have the better at towing you will be at low speeds, but it won’t ever make you faster than the terminal velocity of a single engine propulsion stream …
It’s like a car with tires that slip on the road surface. Making the tires wider will get you better grip, but won’t make you go faster..
I really clicked on this video thinking it was a full size boat lol
Those funny configuration after the failed one was hilarous
Going to need them stl files I’m going to need something to do this weekend. Bad ass build buddy
they're up for the boat now! motors are still in the works
@@PeterSripol any chance you have the stl files for the console and hard top?? I have been searching the internet with no luck. Just want to print a cool display model.
bro, look at the Viet Nam era PTR (Patrol boat, river). It had a two stage impeller and was SO fast for its size. I think it was probably converging on the limit of the maximum velocity of a traditionally hulled boat. Could be very cool to try on the RC scale... Especially as a test to model up for your new large boat....
We need more motors
The boat is already going at it's top speed with 4 motors on it. Adding more motors will not change the top speed. It'll just change how fast it gets to top speed. You could probably double the speed just by changing the pitch of the props on the 4 motor setup
my brother tried to set fire to my house while watching this 🤷♂
Me in build a boat for treasure roblox when i want to drive a really big ship:
I'd say 750000 is too many and 0 is too little. So somewhere in between.
That actually was a pretty sick 80's montage, and now that song is stuck in my head 😆
0:10 - Just a friendly bit of advice... i would stay away from red, blue, and other bright colored drinks before/during you film. I have seen your other videos and nothing looked strange, but this one kept me glacing at your red teeth - no doubt temporary and from the drink - it still pulled attention away from the awesome content you put out. Outside of that, im glad i found the channel - i have been big into RC going back 20 years before drones, multi-access gyros, and even before decent ESC/Brushless motors when nitro helis ruled the competitive scene. Hope to see you at IRCHA some year, just as good as flight-fest but a bit more heli/quad oriented compared to the Flight Test crowd.
As noted by others here, there are a number of other factors that affect the performance that seem to be lacking proper consideration on this model boat: prop pitch and diameter, motor attitude (tilt/trim) and balance of the load--I can assure you that the boat will perform much better if those batteries are moved further forward, and that will decrease any need for additional lift at the stern (such as the empty plastic drink bottles or those smaller hulls), whether it's on a radio controlled model or the real thing--too much weight in the back and it's hard to get it to plane, the stern wants to drop down into the water, and your videos prove that--the extra width can also be a problem, but so can additional length--there is always going to be a point of diminishing returns, so YES, there can be such a thing as "too many" outboard motors--it was still a hoot to see all of the modifications and test runs, thanks for the laughs--
I would have tried 6 tight on the transom. But you did so much work, well done and nice work.
another issue you ended up running into was weight bias and trimming. with the weight in the rear it needed more trim down, or weight up front to balance out.
Great stuff!! Props in the 2nd and 3rd row cavitate and provide no thrust once the boat gets going; they just suck air from the props in the first row.
I'm pretty sure one optimally shaped and high powered prop is the most efficient, maybe two props rotating opposite directions to cancel out rotational torque. Using more than two IRL is more for compromise reasons than to be opttimal; e.g. more small propellers rather than one or two big ones to be able to go into shallower harbours; more props in pods around the ship to get more maneuverability at the cost of less optimal max speed, multiple outboards on a smaller boat to get around size limitations (both physical and legal maybe) of how large an outboard can be before it's impractical; or just because you want more power than the largest outboard that is made etc. (and for some reason you want the motor to be outboard). Outboard engines is already in itself a compromise; by having the engine and propeller combined as one unit you make it easier to add and remove the engine to the boat, and originally most people would detatch the motor and gas tank and keep it at home most of the time and only leave the boat outdoors or in the marina. But with the ridiculously large outboards, and particularly a complex multi engine steering setup it's a huge process to add and remove the engines anyway, so they might as well be inboard engines; but I guess some boys like to brag about how massive and how many engines they have and it's easier for everyone to see how excessive your setup is, if it's all outboards...
FYI; a Mercury 450R costs between $55,000 and $80,000 each,
Each engine will consume 2 litres of petrol every kilometre at speeds over 25 kmh.
So, six of them will use 12-litres per klick.
In NZ, that would cost $34 per kilometre, for the fuel alone!
I love the silliness of this project, but man, that boat looks really nice.
To me as a mechanical engineer the best solution was the first solution(all engines next to eachother). In your experiment due to the fact adding more weight to the back and the torque of the engines it didnt work as well as it could have. I think you should add more weight to the nose of the boat. this will result in better performance up until a certain point. Putting engines in front of another one will not result in an increase of power due to flow interferance of the engine in front. For the mentioned first setup: adding engines will work for increased acceleration(in my theory). however, top speed wise it wil not likely increase up until a certain point as the propellers of the engines will simply not turn faster then a certain rpm(adding 2 engines from 16-18 engines for example will not be likely to increase much top speed).
If i may, try a hydrofoil setup on it with different stages for the motors. 1st is the original 4. 2nd is the additional 8 once the lift is achieved.
the problem you were having getting on plane wasn't the motor configuration as much as the motor "pitch". to get a boat on plane you have to trim the motors up so they try to thrust slightly downward which in turn lifts the nose of the boat and gets more of the hull out of the water so you go faster with less resistance.
you could also put the motors behind the boat but in a stair arrangement so that the turbulence from the motors closest to the boat doesn’t affect the other motors
Peter: Hull is what determines maximum speed, not the size of the motor. At a certain point the resistance of the hull on the water becomes maximum and no amount of added horsepower will make you go faster. instead: the excess pressure in the transom causes it to break the motor mount.
When you lined them up behind each other, I legit had a flashback to how I used to draw boats as a kid. Literally exactly like that, lol
I know it could just be appearance but all the motors within the width but behind the boat was faster. Its awesome!
That was extremely interesting.
I was surprised that was even a relatable problem!
I love the thought and the execution, but i have some thoughts as well.
with all the engines, as you said, adding them in a "series" manner does not increase the effect as much as side by side as there are props functioning on turbulent flow with a lot of cavitation (air bubbles created by unnder pressure for those unknown :) ). My immediate hypothesis is that when using more engines, the torque needed by each motor decreases, meaning you could increase the prop pitch to push more water pr. rpm, increasing the top speed. If the maximum rpm is reached, but the engine is "running loose" (definitian ad hoc now: push
I like how Peter talked trash on the Miami water when his fish tank was absolutely foul smh
Im enjoying all the boat stuff your doing , hopefully your viewers and the algorithm works together to make it sustainable
I grew up down the street from Shawnee Park, literally used to live on N Monroe it's so nostalgic to see it in your videos.
Adding 3 more outboards, but not right behind the others... might be a bit better then 4x3 config. And turning on off the motors based on left/right would help turn
i think the motors set up at 12:30 would be a great idea if you raise them up as you ad rows on behind because with them the same height as the row in front of them when you take off buries the whole motor under the water and the water hits the big part of the motor and cancels out the water flow if they were raised then they wouldn't interrupt the flow of water so much and would help speed up the flow
What if you gave it 12 engines, but made them really small so they would fit behind the boat? OR what if you just had one giant motor
A triangular transom might keep six to eight motors inside the critical footprint without overlapping cavitation.
It's having hull in front of, or over the prop that stops the thrust burying the rear. It should work with the correct trimming to compensate but it would need to be dynamic with each motor adjusting its AOA in accordance to the trust torque .
Peter Sripol is Aeromodelling enthusiasts best 👌 buddy..We as enthusiasts love all your experiments, Hope more from you, Love you 😍
I think that the main contributing factor to the top speed of the boat is how fast the motors themselves are spinning. To put it in a different example, lets say you have an RC car with a motor on each of the wheels. If the top speed of the motors will only push the RC car to 10mph, then it doesn't matter if you have 2, 4, 12, or 20 wheels driving it forward, the top speed will still only be 10mph. That is essentially what you have here. Having more motors that are also pushing at the same speed isn't going to make it go any faster. It might have more thrust, but that thrust still has a top speed.
That said, the correct number of outboards = the least number of outboards it takes to give it the maximum amount of acceleration and top speed. If you can do it with less motors, than it's more efficient.
This kind of setup is usually used for boats that transport illegal substances over the sea. The only limit is fuel efficiency and the police boats (they have to be faster than a police boat).
More weight in the front will definitely help. I have a john boat that can only get on plane with 4 people if 3 of them are all the way at the front. Even if you added weight that wasn't there yet it may help
You came to the right conclusion about the motors. You didn't try adding ballast to the bow of the boat to keep the bow down and help it get on plane better. Doing this should help to reduce drag and increase speed. There is a fine line between balance and nose dive, have fun.
That's a sweet looking 3D printed Center Console 🤙🏻
Correct number of Outboards is what your boat transom tells you you can put on it which is normally in horsepower. I watched a fellow get a hard bottom inflatable boat which was rated for a two horse power motor and he put on a three and a half horse power motor because he said that number that was on the transom was just a suggestion which is not very smart of him. Eventually he might start having issues with his transom breaking or bending or cracking because of the extra weight. Always go by the manufacturer's recommendation
Looking forward to your stl file. I'm waiting here
Trim the first configuration either in total, but at least the left and right 4 motors. Fun video.
The one thing I didn't see you try, was to change the pitch of the motors to help get the boat 'on plane' as it comes up to speed.
can we just point out for a moment what a beautiful boatdesign this is! 😀
so glad you tried all the configurations and went 12x maybe a prop swap for the successive layers of motors like each row gets more agressive pitch props basically each row being a stage ... uh oh you forgot to do single file 12x outboards can't wait to see 🙈 the results ❤
Those stl files would be sweet! I really dig the hull design
Stls for the hull are up now!
Why not mount fore to aft Hull, so they are like "Bow" Thrusters, spacing them out under hull, staging port & Starboard there layout so they don't interfere with each others "wash" ... or just go with 2 ducted Fans (EDF's) on rear to push water ... ;)
If you wanna have more motors behind one and a other they need to rotate differently for it to have a effect
And to boost this kind effect to the max the turbines need to be inside a tube
So small explanation the one in front rotates left and the one in the beck rotates right and tada more speed this concept is used in some wind tunnels btw
I think you should have two long arms at the front with an air foil connecting between them with motors mounted on it... The air foil should be lower than the rear motors...
Some of these configuration I wonder how much you were limited by prop pitch and hitting pitch speed with the boat (speed where your prop has no slippage and theoretical max speed of a certain pitch/rpm combo)
You could have used toroidal propellers to reduce sound and increase efficiency. Its possible to print but bit more hard since its a complex shape in such size.
Good vid. Have been considering adding a 2nd motor on my dinghy.
Got to change the pitch on the props to increase speed. Example, 5000 rpms at 12 inches (pitch of prop) of travel per revolution is a constant no matter how many horse power you have. 5000 rpms at 24 inches (pitch of prop) of travel is twice as fast. More horsepower (more motors) allows you to reach the 5000 RPMs at a higher 24 inch prop pitch
In addition to being in turbulent wake, realistically the props can only get the water up to some speed V_max. If the water a prop is ingesting is already near V_max, it's not going to make a huge difference in the speed of that water and thus the thrust produced is going to be marginal at best.
At the end of the day the force you can produce is going to be the difference between momentum of the water in vs momentum of the water out. If there's a small difference in momentum, there's only a small difference in force.
Looking forward to those stl files!
Great video!
The first outboard config was the best. Bring the nose down and your motors will work.
Your fore is lifted too much with the aft propulsion and weight. Moving ballast to the front or a downturn hydrofoil to direct the fore down. I also think a hydroplane version of this would be pretty sick
The in-line config interferes too much with the prop and rudder efficacy. Too many bubbles and not enough water to grab. A single row perpendicular to the keel is optimum rather than stacked,
Moderate adjustments may be needed for the rudder config
you would need props that are designed to run at a higher speed. the extra outboards would provide the torque to pull a taller gear.