Aggressive Mini Speed Boat Sketch...would it work?

Discussion in 'Boat Design' started by LilWake, Jan 17, 2013.

  1. WestVanHan
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    WestVanHan Not a Senior Member

    Wow...you not even gonna bother replying to the insults.

    For one thing,you think because a boat won't sink it's safe....you should talk to an acquaintance's widow and kids,see how they feel about that.

    Guess you've heard about lawsuits? You and a friend crash,he's paralyzed,injured or dead. A boat designed by you= their lawyers are going to jump up your a55 and you'll lose everything you have,or will ever have.
    You'll be living in a van,as your insurance company will wash their hands of you.

    You get hurt badly or killed-same as above. Your life insurance will be voided-nice thing to leave your family.

    Ought to be grateful people have replied.
     
  2. johneck
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    johneck Senior Member

    When you start a design it is useful to know what your design goals are. In this case it seems that you just want "different". So in that case go for it. I looked at the log of your conversion of an outboard to a jet, so I have no doubt that you can build it. And judging by the previous build it will probably look beautiful. The issue is how will it perform? Will it be as fun to drive as look to at sitting on the trailer. Since you will only build one, you probably should stay closer to something you know works below the waterline and let your creativity go above. Jetski manufacturers have spent years and built and tested hundreds of prototypes to get where they are now. Why not piggyback off that effort and make the hull something close to a 3 person jetski hull? They are about the same size, weight and use the same powerplant. Seems like a no-brainer. I would even go as far as saying makybe you could cut the top off a 3 seater and build your own thing on top of it. You are much more likely to get a great boat that way.
     
  3. LilWake
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    LilWake Senior Member

    I have considered designing from the lower hull of a large jet ski, but the problem with that is the narrow beam. Because they are meant to sit on top of they are generally pretty narrow to have side by side seating. I'm sure it would perform great though. I wonder if there would be a good way or widening a ski hull, though that might be just as likely to impair the performance.
     
  4. Jet_Love
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    Jet_Love Junior Member

    I'm a shade tree engineer and builder as well as the open water test polite. I like your outside the box thinking lilwake and think you should build the first sketch. It looks like a newer Yamaha bottom design to me. I can see how your thinking might work. The mini I built out of a three seater pwc runs faster on top end then the ski did its self with the same stock engine. I'm thinking its from more air under the hull or the hull being wider but not sure as I'm only a shade tree engineer and did more than one thing at a time. I have over 100 hours of run time on my the boat. It has shown no ill tendices what so ever. Its has been 3 to 4 feet out of the water at over 35 mph many times. It has been crossed up in the air and straighten up once back in the water. The more weight you put in the better it handles and rides.

    The thing I see most by looking at your sketch is seat placing. I don't see how you could get the cg's right setting so far up front on a 12 footer. To get 60 mph your going to have to be on the pad and to get on pad cg's have to be right, not so much the amount of hp you have to work with. I'm getting mid to high 50's with 110 hp.

    I have piled up and burned projects with lots of hours and dollars to appease the boat gods. Lots of great cutting edge out of the box designs came from people with no degree at all not even high school. Bottom line it's only one way to find out, Build It! Good Luck...



    Here are some pix one boat I built out of a three seater ski you may have seen.
     

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  5. Jet_Love
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    Jet_Love Junior Member

  6. LilWake
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    LilWake Senior Member

    Jet_Love, I love your boat man! I know another guy building a 1300cc JetMate almost exactly like you did yours. If you hit high 50's with yours I can't imagine what his will do! He's almost done but the winter kinda stalled his build. Do you have more pics of yours or a build thread somewhere. I would love to see the entire build and finished photos!
     
  7. Jet_Love
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    Jet_Love Junior Member

    Thanks Wake,
    No build thread sorry. They take so much time and your's pretty much covers it how to.

    Now that I know it going to work. I'm getting ready to tear it down and slick it out with turf and a woody wrap. I call it log ride. I was going to do the bigger 1300 cylinder but no need to for me. It's fast as I care to go and does good on fuel.

    Starting with a proven bottom like some said is the easiest way for me. It makes for a very simple build and its a bolt in bolt out. I'm building a FX140 Mate now and it has somewhat of a steeped bow.
     

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  8. LilWake
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    LilWake Senior Member

    LogRide...that is epic! bahaha! That's going to look so cool! You should do green hydro turf cut out in leaf shapes pattern
     
  9. johneck
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    johneck Senior Member

    Jet_love, your boat looks great and appears fast. It looks to me that you did exactly as I described; you took a jetski hull and modified it above the working part to make the boat you wanted. When you are running flat out, you basically have a jetski. The added beam probably does help a bit and you are right on about the CG location. Weight and CG are the key elements for a successful planing boat.
     
  10. Jet_Love
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    Jet_Love Junior Member

    Hi John,
    Thank you sir. I did do as you descrided. People started grafting just pump's from ski's and the fabing up engine mounts. I learned quick it less work to do the whole bottom. Plus if its a old design hull you get a new one of your liking and yes it's pretty much a PWC. The cg's are so close I can trim by leaning forward or back(I got lucky). The Kawasaki Jet Mate I started with was a flat bottom jet. The PWC gave me a V bottom.



    Hahaha, good ideal, green might look good . I'll have to find a palm tree um brella too.

    I did a little work to your drawing. I was thinking if you build a boat from stratch make it all around. Two seaters are cool for crusing but in most states you have to have at least a three seter to pulla skier. A seat for the driver,spoter and the person being pulled in case something go's wrong. So build it more like a Jet Mate lay out is my thinking.
     

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  11. Jet_Love
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    Jet_Love Junior Member

    Here's a bottom bow pic of a Yamaha 02' FX140 hull. You can see it's steped. It's what's going in my next Jet Mate build. I think this design is still being used in 2013 Yamaha PWC's. "They" say it makes for more of a dry ride, better handling and speed.
     

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  12. PAR
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    PAR Yacht Designer/Builder

    Lilwake's boat as drawn will not plane off, without an atomic reactor, and with that, it'll trim at about 20 degrees bow up. Jet-Love, that's not a step, but merely a spray stripper, which is quite different. A stripper on PWC is of dubious effect, though it can help shear/deflect spray to some degree.
     
  13. LilWake
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    LilWake Senior Member

    It's comments like this that make you look like a giant douche. Couldn't this post have been made without it? The answer is yes. This type of comment might fly by me if you were a friend, but I don't know you so you come across as somewhat bitter and senile. I know there is a fine line here that you seem to be completely oblivious of.

    Why don't you stick to what you know...yachts?
     
  14. Boat Design Net Moderator
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    Boat Design Net Moderator Moderator

    Let's please try and keep the forums polite to one another and not go further with the jabs or insults. Sometimes someone's intent doesn't come across in writing as it would face to face.
     

  15. WestVanHan
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    WestVanHan Not a Senior Member

    There are miniboat forums around...
     
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