Need a boat built

[flraptor07]

Keith Bradley 45" hull

Here's the new Keith Bradley 45" Full Carbon Fiber Cat hull, deffinetly the nicest hull I've worked with by far.. No need for a extra inlay with this one, it's already plenty thick. http://forums.offshoreelectrics.com/...adtek-Cat-Hull

[keithbradley]

I know you're not asking me, but I don't think these are otherwise going to be answered.

Ok. I don't mean to question you but amp draw would be a big part of a reliable setup correct?

Yes, of course.

How do you size the speed controller and batteries?

This would be relative to current draw and runtime.

In my other RCs we try to keep things cool. Does the water cooled boat speed controllers do a much better job of this?

Yes, but because of a much higher current draw, the cooling affect is pretty comparable to cars.

And what about motor load? I'm sure different props affect heat too. I only ask because I don't know. With car ESCs there is usually a data log. I assume boat ones are the same.

Yes, load is important and prop size/pitch/type obviously directly affect load. Excessive motor load will eventually cause parts failure EVEN when the current draw is well below the ESC's current ratings and temperature is within normal limits. This is why getting the right combo is so important when moving up to boats in the medium to high speed range.
Some marine ESCs have data loggers, some don't.

What have you seen with your other builds? Would you test it before shipping it? Thanks I really appreciate you taking the time to answer my questions. By the way, I saw how you seal your hatches. That is an awesome idea. I hate taping the hatch on my Revolt and Lucus boats.

Seen in other builds? Is this question in regards to current? This will depend on how well the boat is set up, but it will nonetheless take a given amount of power to go a given speed. Energy relative to speed is always squared, so it will take substantially more power as you go faster and faster. I've seen anywhere from 0 to 1200A in testing.
As far as testing a boat, I don't normally test customer boats, but I can't speak for other people. At this point, I've built enough that I feel confident in how they are going to run. I can typically hit a projected speed point within 1-2mph. My customers also know that I'm not taking a shot in the dark or guessing when I build their boats. I have enough experience and legitimate, documented runs to assure people that I can deliver on promises. If I was building something that I wasn't confident in, I would consider testing it out. I did this for a customer with a 47" cat that I built last summer. I didn't like the bottom design of the boat but he really wanted me to run it before changing it so we could make a comparison. I think the maiden was 49mph, and after some bottom changes I took it back out and ran 77mph.

[keithbradley]

Oh, and I agree...using a hatch seal was a great idea.

[keithbradley]

I'll shamelessly admit I haven't built enough boats to hit a projected mph by 1 or 2. The boat I'm building right will be tested before shipping. I'd rather catch any issues myself then have something happen after the person gets the boat. Like I said before, I'm not in business to build boats. It's a hobby to me. I enjoy building and take pride in my work.

No shame in that. It definitely took me a few before I could do it!
I think testing the boat in your case would probably be a good idea, but this presents a question...

What if someone wants a 85mph boat, and you test it and it only goes 80. What would you do then?

[flraptor07]

I can't speak for Travis but if I built someone a boat without having a lot of experience, I would not promise a specific speed. With that being said, if you're building someone a boat chances are they don't have the knowledge or experience to build thier own and probably would cr-p down both legs when they pulled the trigger on a 80mph boat..

[iridebikes247]

Just ship em a grossly over sized prop it'll go fast alright, just not for long lol. then say user error, musta done half throttle, etc etc.

In all seriousness I can't imagine building one of these things for someone that goes 81mph when the terms agreed on were 85, but im sure there are people out there that would want every cent back (imagine selling a full size car to them, lol).

Building for a customer is no joke, boats are hard enough to build but I imagine this is the easiest part as you're in complete control, from picking out a hull on a website to running it on their own lake at 85-100 mph is quite a process and could give both parties a big headache especially if they're separated by time zones, continents, etc.

--Its easy to call em toy boats but the building processes, knowledge and fundamentals aren't easily learned or acquired, thats why of the thousands on this forum and others there I'd trust very few building a boat.

[T.S.Davis]

Is it still a toy at 80mph? IDK. 80 is a bunch O' miles per hour.

Keith, you must walk this line all the time. You simply can't know the experience level of guys wanting you to build stuff for them. Then you build it and release it unto the world. "Fly be free!" Then you hear it was burned into a seawall at 80 mph or maybe something worse. Scary. Might be worth having a piece of paper that says you're not liable.

I was asked to build a 96" twin cat for Borsch. 3080's, 12s2px2, Schulze 300's, the works. Him with twin turbine experience but zero FE experience. Kinda glad that fell through.

[nata2run]

Couple of things I would consider.... If getting a high performance hull like the mentioned HPR, MHZ or what ever in the 40" plus class, then twins are the go. That's what they are designed for, and that's where you get the best performance out of the hulls. Those hulls usually have hardware matched, MHZ have theirs and so do HPR. Other manufactures have hardware that will fit, but you should consider those maybe in a later build, or down the track when you decide on a new boat. Unless of cause you insist on particular hardware or someone recommends it for you. Why Lehner? What do you want to achieve and how much do you want to run your boat? Did you know that a HPR 115 with TP motors can make it way past 100mph? Safely, if setup correct. I would honestly recommend, since you are in the US get Keith to set you up a quality hull with budget electronics and see how you go. When you feel ready to step it up and spend an extra 2.5k on motors and ESC's then you can upgrade. I Would not recommend a high performance setup for you, doing 100+ mph it's simply dangerous... Pick someone with experience to do your boat, and make it clear you want to be able to upgrade when your ready. People that are asking questions about motor size or kv, cell count and so on, would not be the right boat builder for you. They should simply know what a safe setup for you should be.

[properchopper]

I can't speak for Travis but if I built someone a boat without having a lot of experience, I would not promise a specific speed. With that being said, if you're building someone a boat chances are they don't have the knowledge or experience to build thier own and probably would cr-p down both legs when they pulled the trigger on a 80mph boat..

Very well said - Thank you

[tlandauer]

not just toy boats..

I have seen this picture half dozen times, only now in my hotel room in China do I realize it is a real boat!
ANOTHER REASON WHY I SHOULD NOT AND COULD NOT RACE!

[keithbradley]

Is it still a toy at 80mph? IDK. 80 is a bunch O' miles per hour.

Keith, you must walk this line all the time. You simply can't know the experience level of guys wanting you to build stuff for them. Then you build it and release it unto the world. "Fly be free!" Then you hear it was burned into a seawall at 80 mph or maybe something worse. Scary. Might be worth having a piece of paper that says you're not liable.

I was asked to build a 96" twin cat for Borsch. 3080's, 12s2px2, Schulze 300's, the works. Him with twin turbine experience but zero FE experience. Kinda glad that fell through.

You're right Terry. There are a lot of people who have never even ran a boat and want to start out in this hobby at 100mph. Many don't understand that a boat needs to be set up properly to run those types of speeds, and a bit of driver experience and caution is needed as well. I have been asked by a number of people to guarantee that their boat will go a given speed when they run it, and of course I decline to make any such guarantee. This is the part where me and the customer have a talk about what it takes to run boats at high speeds, and the value in starting slower and learning how to set up a boat before jumping in head first.

Shawn is a member on this forum and KBB (Screen name Apophis) who is the perfect example of what "speed chasing" looks like when done intelligently. Shawn posted on KBB about a year ago after seeing a youtube video with a Daytona running fast (I think maybe in the 80s if I remember correctly). He wanted to build a boat and run 90mph but was doing research before starting. I thought I was breaking his heart when I told him he needed to start slow and learn how to tune the boat while moving up in speed, and I fully expected him to move on with a "screw that" attitude. (I don't mean to be pessimistic, but that's the most common reaction). Instead, he took it slow and learned how to set the boat up at lower speeds and learned how to go fast without just adding voltage and prop size to a bad setup. I think his best speed with his Daytona so far is now 98mph, and I expect that he will break 100. He now has what I'm pretty sure is the fastest Daytona on the planet, and he did it by learning what works best, not by reading someone else's thread or watching someone else's youtube video and trying to copy their setup. Not to bad for someone's very first build I think...

I guess what I'm trying to say without actually saying it is that NOTHING can replace experience. Now that Shawn has figured out how to run 98mph in a Daytona (without parts failures I might add), I think it would be relatively easy for him to do it again as well as go even further. I would feel comfortable with him building me a boat to run 90s because I know he's already done it.

Why did Tom have you build that boat Terry? Too busy buying big expensive mystic cats?

[Waverider]

I know you're not asking me, but I don't think these are otherwise going to be answered.


Yes, of course.


This would be relative to current draw and runtime.


Yes, but because of a much higher current draw, the cooling affect is pretty comparable to cars.


Yes, load is important and prop size/pitch/type obviously directly affect load. Excessive motor load will eventually cause parts failure EVEN when the current draw is well below the ESC's current ratings and temperature is within normal limits. This is why getting the right combo is so important when moving up to boats in the medium to high speed range.
Some marine ESCs have data loggers, some don't.


Seen in other builds? Is this question in regards to current? This will depend on how well the boat is set up, but it will nonetheless take a given amount of power to go a given speed. Energy relative to speed is always squared, so it will take substantially more power as you go faster and faster. I've seen anywhere from 0 to 1200A in testing.
As far as testing a boat, I don't normally test customer boats, but I can't speak for other people. At this point, I've built enough that I feel confident in how they are going to run. I can typically hit a projected speed point within 1-2mph. My customers also know that I'm not taking a shot in the dark or guessing when I build their boats. I have enough experience and legitimate, documented runs to assure people that I can deliver on promises. If I was building something that I wasn't confident in, I would consider testing it out. I did this for a customer with a 47" cat that I built last summer. I didn't like the bottom design of the boat but he really wanted me to run it before changing it so we could make a comparison. I think the maiden was 49mph, and after some bottom changes I took it back out and ran 77mph.

Thank you for this response.

[Waverider]

this is exactly the reason I'm building a rivercat for my customer. because im comfortable with it. Also the same reason its a single, because i'm comfortable with it and I know it works. His setup is extremly close to mine, just done a little nicer than mine (not taking anything awayfrom mine...just learned more since that build). Like Ive stated before, Im still failrly new and constantly learning but I'm
bowing out of the building for people. My experience pales in comparison to most people on here so i guess i dont need to build anything for anyone but myself.

Now I'm really confused. You offered to build a 45" twin motor boat with my 80 mph goal in mind. Then you say you have never built or run anything like that before but you would still built it. And now you won't build one for the same reason. The reality is I was just tossing out an idea. If you would of said you are more comfortable building a smaller single motor boat I would of respected that. Maybe I would of asked someone else or maybe you could of talked me into one. I just want something better then what I have now. I'm disappointed. I will look at options with the other builders recommended. Thanks everyone for their response and input.

[revoltrunner]

Its a real shame this thread had to turn into what it did.

[Waverider]

In all honesty, If you want a boat built, you should lower you speed goal right out the gate. You might have owned fast rc cars but a boat is a whole different ball game. 60mph is a good starting goal. Then you move up from there. But Like I said, i'm bowing out of this. You choose whomever you like. At this point, Ive lost all interest.

Now you're being honest? Before you were ready to take my money and build the boat "no problem"! Now you say I should lower my goals? You wouldn't answer my questions directly but told me in a message you "just know from experience" what parts to use. I think we are done here. I'm glad your customers are happy with your service. I just hope you don't mislead any future customers.