[


Ok ... so then with our little guys cranking out at roughly 40 MPH and an average length of 36 inches ... and say a racing airboat meaures roughly 18 foot , then that would mean that those RACING airboats crank out at roughly 240 MPH

[X(][X(][X(][X(][X(][X(][X(][X(][X(][X(][X(][X(][X(][X(][X(][X(][X(][X(][X(][X(][X(][X(][X(][X(]


So , what does this mean in short ? It means that WE have to configure OUR little guys WAY more , than those bigger ones ...

Terbo, the drag boats are only 11-12', not 18'. An 18' boat is used as tour rides and such.

What I am saying is that they use the same physics and principles as the big boats. My boats are 1/6 scale and hitting 40, possibly even faster. So yes, I am running faster than the big boys. The top fuelers are hitting 140+

My horse power to weight ratio is real close to the full size pleasure boats. Just like my lil boats, the full size boats that my friends build are around 5 lbs per horse. The top fuelers are running around 1/2 lbs per horse, some guys are running between 2500-3500 hp on their boats.

When I started into the r/c boating world, I also had the thinking of, being around and building full size boats, the little boats should be a walk in the park. My first hull was perfect to scale, not one defect, I was all smiles until I put that bad boy in the water. It ran great until I tried to make that first turn, look like a tornada reached down on it.
Main Entry: horse·pow·er
Pronunciation: 'hors-"pau(-&)r
Function: noun
1 : the power that a horse exerts in pulling
2 : a unit of power equal in the U.S. to 746 watts and nearly equivalent to the English gravitational unit of the same name that equals 550 foot-pounds of work per second(lift 550lbs one foot in one second)
If we used only the HP to weight ratio, the full size boat should run alot faster than 140+mph, the truth is there is too many more factors that must be added in. ex: 30" boat with a 2hp engine has a speed of 40mph(just a given speed) does that mean if you was to replace that engine with one that has 4hp, the boat will have a speed of 80mph? Would be nice if it did. Or if you replaced the 30" boat with a 15" boat(also 1/2 of the weight) that it would have a speed of 80mph? Also would be nice if it would work that way. The main thing that I'm trying to say is a boat that is perfectly scaled down from the full size will not have the near the preformance that it could have.

There ya go ... Hal hit it RIGHT on the head of the nail

One more thing to note ... we ALSO have to our adjustments a bit more precise as well .
For those that know nothing about real , full sized boats , then go in the opposite direction ...
Say , you are running the same 36 inch boat , now make that a 18 inch boat and try running it at the same speeds ... ( gonna need a LOT more fine tuning that what you had to do on the 36 incher )

So, Bob, where is it you do your skiing and surfing? You seem to know quite a bit about these water sports, for one who is landlocked. yes surfers move on the board, this is what makes the board turn. If the rider stands still, the board runs straight (though this does not give points in a competition) And perhaps you did not notice that on water skiis, the riders feet are strapped down, no way to move them, and again shifting weight only results in manuvering the ski. I use these as examples because I know them(skiing since age 4, surfing since about age 8 - piloting ski boats, powerboats, sailboats since age 12) if you want to know what kind of forces occur in a system, there is nothing like sticking your face in it. BTW the forces applied to skiers and surfers are both internal and external, just like a 'self contained' boats. Gravity pulls on surfboards (at a rather constant rate), the surfer must push back, the rope of a water skiier pulls him along, he must pull back. An airboat prop pushes or pulls on the air, and the air pushes or pulls back. Newtons' second law - for every force, there is an equal, but opposet force.

LOL ... I guess becuase I LIVE currently in Iowa , means that this is where I was born ? Up , untill 15 yrs ago , I was in Florida , BORN AND RAISED . ( Still own a home on 7.5 acres in Brooksville on Old California - for those that know/live in the area ) Also ... I did a WHOLE lot scuba diving ( down at John Penacamp park ) went sking ALL the time ( mostly out at Homasassa Springs and Hernando Beach - had a buddy who had water front property ( in Hernando beach )where my boat was docked - since I was "land-locked" LOL ( as well as snow sking on Mt Diamond in R.I. ) , and tried surfing ( but did NOT like it . )
So , yes , I DO know about these .
Background - Was born in Andytown Fl ( which is no longer there , was at the junction of US27 and Alligator alley ( when both were skinny 2 lane ) , then moved to Davey , lived there for quite a few years , then went down and thought I was rich and lived on the inter-coastal in Ft Laud , then moved to Brooksville .
Did LOTS of sking ... so yes , I DO know about it .
And why did I move ? Because I got tired of all the drugs and BS there , along with NO SNOW and NO change of seasons ( per say )
here , there are NO scorpions , no swamp smelling rains , and no , N.Y.'ers .
Anywho....
If an airboat ran better with the engine located in the middle of the hull ... they would ( the manufacturers of real ones ) would have come up with something by now )

That is because it isn't pratical. If the prop was more forward in the full size, you would not have any room for passengers or cargo. Each person has their inspiration for their building...mine comes from tweaking what I know about full size boats, then pushing the limits of the physics of the airboat into the little ones....then let the videos do the talking.

Are there any engineers around here? There are five significant forces that any engineered boat of any size has to deal with; weight, buoyancy, hydrodynamic lift, drag, thrust, and power. This applies to airboats as well, but with significant more difficult calculations to figure. Therefor making testing key. You need a high thrust to weight ratio with a hull design and center of gravity placement that stabilizes the craft at all speeds. The debate of puller or pusher is an irrelevant question without knowing specifics of the hull size/weight, engine type and its position on the hull, as the center of gravity can not be calculated otherwise. With all that said, a given hull will react and handle differently with one setup vs the other, but can be made to work successfully, but with varying results.

The original question, which is better and why? is unanswerable without specifics.

Your absolutely right Cochese!

Did you consider everything into your calculations? Such as....the weight of the cage, the weight of the motor, the CG of the boat, the balance point, the weight of the grass rake, rudder proportion, the actaul boat weight, etc. If your gonna be precise, then you have to include everything. If you do not scale this down from the full size also...your not getting a "perfect" scale down...probably why you were disappointed.

I may be right, or not. But I know I would not ride on a fullsize airboat with a prop swinging a few feet away and nothing between it and me. I agree with the idea that a puller design not being produced in a fullscale airboat is any indication that a pusher is better, is irrelevant. Design possibilities with scale models allows for many more design choices and ideas since rider safety is not required in the design. I have seen both pullers and pushers run and they both appear to run real good if dialed in and designed well. Oh, and let us not forget the driver skill is a big factor on how a boat appears to perform and handle versus its maximum potential performance and handling.

Ok ... now that we are trying to get into the engineering aspect of things ... lets go this route ...
It takes an architect/engineer to desing things , like houses and such , BUT ... it takes the carpenter to make the alterations needed for the architect/engineer's design to work .

Now ... Who...
besides HAL and myself, has ACTUALLY done this TRUE comparison on the SAME hull , WITH the SAME engine ?
So ... before all you "guess'ers" start flapping ... please ... try doing .

Again , I did NOT say ... same type of designed hull ... I said SAME actual hull , SAME actual engine .

Apparently you know very little about the construction industry. The carpenters (or any trade) can not make ANY alterations to the bluleprints with out submitting a "change order" to the engineer, who will review the "change order" with the architect (you know, the guy that designed it for the carpenters). By the way, I work in the construction industry too....18 yrs now.



I have. There was two gentlemen here in town that built some full size looking boats with pushers. When they were complete, they would barely move on the ground. After talking them into turning the motors around before giving up (they were frustrated, ready to start over)...they scooted across the ground nicely with the switching. Instead of building new boats, they ran the ones they had!

I have been building rc airboats for 8 yrs solid, I built my first airboat 16 yrs ago, not to mention being raised around them. I am closing in on around 200 hundred boats that I have built in my time. I have boats in 3 countries on two continents....I've done some howework over the years. I am just voiceing my opinion on what I base my buildings on.

Which reminds me.....where are your vids? You talk the talk...show us your walk.

Next time you start "flapping"....think about it.

I too would like to see what you are talking about.

Ok Chris ,
Quite playing the games ... you KNOW that they were posted at each time they were taken .... And your claims about all those airboats and the constuction business ....
Well , yeah ... right , ok ....
Anyway .... If you Are , or WERE in the construction business and you do NOT know what I meant ... then it kinda makes me wonder WHAT you do ? I also WAS in construction when I lived down there . I was a Brick layer ... NOT block layer and I also layed stone as well !
When you work with dimensional wood ... they have a tendency to WARP and twist ... but its up to the carpenter to WORK with that wood that the arch/eng draws as a PERFECTLY STRAIGHT/square piece of wood . And a Plumber has to work in same way .... ADAPTING !
And doing what I did as well applies .... Lay a stone chimney and tell me you can go EXACTLY by the prints and I'll tell you , you know ABSOLUTELY nothing about this !
YOU are NOW talking the talk ... so start crawling Jose' ... :cause you SURELY can't walk it !
And FTR - You think because you started this RC bus you are doing AFTER this forum got started ( and NOT by you , I might add ) that now you are some kinda "expert" , think again ....
HAL is the only one that I know of that builds a professional looking and running RC AIRBOAT ... MADE of WOOD ... not foam , like some Toy .
And since you are trying to sound like you make such a PROFESSIONAL rc airboat , then explain to me WHY , in ALL your vids , your boats PORPOISE ! And the vids I seen of HAL's boats , do NOT ? Are you gonna claim that 'hopping" - aka porpoising , is SUPPOSED to be the way they run ( since you build REAL airboats also , as you claim )

or maybe what I am seeing is these vids is just a figment of my imagination ..

http://rcairboats.net/v-web/gallery/...Blue/BBwet.wmv

http://rcairboats.net/v-web/gallery/...fulgainer2.wmv

And there are others as well ... these are not just a few "select" few ...
Seems with yours , each time you get them opened up , they hop . Whys that , if your such a PROFESSIONAL builder that has been building for


And FTR - I think you need to go BACK and re-read what I ALSO said ...
Those were IMO ( which , FTR means In My Opinion , oh , and FTR means - For The Record )

Now ... AGAIN ... what I said , was based on what I HAVE DONE ... And anybody that has been here LONG enough , KNOWS that I reversed my engines ( AND posted vids of it EACH time ) and showed how it ran EACH way ! No .. I did NOT do a vid to vid comparison .... I simply was "trying" things at the moments .
AND , as I stated early in my posts ... those are based on what I posted as results ...
And I am done wasting space on this thread with this ....
We can at this all day long ... like the old arguement about Chevy and Ford ....
So ... I am done

You know the more you open your mouth...the more you show your true colors. Let's take construction for instance. I work as a foreman for a "General Contractor", I am responsible for the job from start to finish. You are/were a mason. There's a big difference being a mason and general contracting. A mason holds a specialty license and can ONLY do mason work. Unlike a General Contractor, who is unlimited with their building capabilities, a GC does the job from the property being surveyed right down to polishing the door knobs when it is ready to be "CO-ed". I'm in charge of the trades on my jobs. I also know the proper procedure for making "alterations" to a project. So, take your "flapping" and your "guessing" somewhere else.

Lets talk about them videos...you still haven't showed us any! Come on, show us your capabilities and how perfect your boats run.
My videos you are referring to...I still don't see the porpoise. I see a flat bottom airboat running over choppy water. And if you had any full size boating experience, you'll know rough water and airboats are a bad combination. In the vids, I am running on 1.5" chop, my sides are only 2"....so how can you expect the boat to run flat on rough water? (another indicator of your experience).



LOL...I started a website because of my passion that I have for the little airboats and I wanted more out the forum and site than what others were offering. My site is totally dedicated to rc airboats, unlike the others which cater to other forms of rc's also....which makes neither site better than the other.

Do some research before you make allegations. I build from wood and foam. And I will take you on with my "toys" anyday. Once again....show us some of your work. I have videos posted all over.

I never stated that I built full size boats. I said that I have a couple of friends that build them for a living which also drag race them. I have grown up around them all my life. I was born and raised on a 750 sq mile lake. So be sure of what you read before you start "flapping".

I don't care if you think my small businees with the airboats is phony......Yes, I do and have sold the little airboats, when my full time jobs allows the time for it. (we have had a few hurricanes down here in the past years which has created alot of work in the construction industry, which hasn't left much time in the past months for my building, when you work 6 days a week to bring home the bread for the family) I'm closing in on 200 boats built and I do have them on 2 continents. Believe it or not.....its a fact.

I have met alot of great friends throughouot the world on the internet since I have been on the net. Those that know me know, know who I am and the passion I have for my hobby. Just because I started a site dedicated entirely to rc airboats doesn't mean that I am any better than anyone else, besides, its the members of the site that make the site what it is, I just have the rights to the domain. I am proud of everyone of them just as much as I am proud to be a member also! Just like I'm proud to be a member here!

With that said...I will no longer waste RCU's or my time and space on you.