The LOOSE GOOSE Custom Build

Discussion in 'Boatbuilding' started by NeverYachtz, Aug 3, 2013.

  1. NeverYachtz
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    NeverYachtz Junior Member

    This thread will detail my summer project. I am a mechanical engineering student at Sacramento State, life long boater, and boat design enthusiast. My main inspiration for being an engineer in the first place was watching Fountains and Cigarettes cruise by at 80 mph when I was a kid. I've learned a lot about different aspects of engineering since then. But this project is going back to my roots.

    The plan is to design a custom stepped hull using CAD. Have the hull machined into a foam mold by a local company. Lay up the hull with either fiberglass, carbon, or a combination of both. Then install the parts, test, run, test, run, drink beer, etc.

    Another hobby of mine is using Solidworks, so the boat, and every part, will be fully modeled using that program. (I got the student edition for free :D)
     
  2. NeverYachtz
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    NeverYachtz Junior Member

    I originally started a build thread on the electric r/c boat forum here:

    offshoreelectrics.com/-The-LOOSE-GOOSE-Custom-Build

    Some of the first design iterations can be found there if anyone is interested (however the pictures might not work if you are not a member). I have been teaching myself about hydrodynamics and stepped hull design for the past year or so by reading threads on here and similar forums. The design is 100% my own, with cues taken from other r/c boats and successful production hulls as well.

    Here is the progress thus far:

    Design:

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    Molds:

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    Foam:

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    Styropoxy Coating:

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  3. NeverYachtz
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    NeverYachtz Junior Member

    SPECS:

    HULL
    LOA: 45" (1/12 scale, assuming full size boat is 45')
    Overall Beam: 11"
    Chine Beam: 10"
    Transom Deadrise: 24 degrees
    Maximum Deadrise: 43 degrees

    POWER
    Motor: 2x Leopard 4082-1600Kv
    ESC: 2x Hobby Wing SeaKing 180
    Battery: 4x 3s Lipo 5000mAh
    Servo: HS-5646WP
     
  4. NeverYachtz
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    NeverYachtz Junior Member

    The build plan is to use the foam as a plug, make a mold from that, then make the final hull using the mold. I'm trying to imitate a real life production process as much as I can because this is first and foremost an educational project.

    Everything will be laid up using vacuum resin infusion. The exact materials haven't been finalized yet. It will however be a combination of 3K carbon fiber, 6oz glass, and some kind of gelcoat.

    A lot of questions will be posted on here as I get closer to production. Everything I am doing is for the first time, so I will need a lot of help along the way.

    Thanks for taking a look, any comments or suggestions are welcomed.

    -Blake
     
  5. lewisboats
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    lewisboats Obsessed Member

    Not to be mean but you will have to reduce the size of your pictures. They are far too big and most people won't want to follow a thread that they have to wait interminably to read. Forum guidelines are for 640 x 480 to 800 x 600. Looks like a nice boat but even my 28" monitors are too small to see it all at once.
     
  6. PAR
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    PAR Yacht Designer/Builder

    Instead of having the foam milled so you can layup over them, you should consider having it milled so you create a female mold, laying up inside them. You'll have a much more precise control over surface quality and fairing chores.
     
  7. dougfrolich
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    dougfrolich Senior Member

    I'd give MPYD a call to make sure URAOK.
     
  8. NeverYachtz
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    NeverYachtz Junior Member

    Sorry about that, I re-sized the pics.

    To clarify, the mold I am making from the epoxy coated foam will be a female mold. That gives me the best surface finish and overall production quality. But I will be asking quite a few questions because I don't know much about gelcoat, layers, etc.

    And yeah, I would be overjoyed if Michael Peters took time from writing PMY articles and designing beautiful yachts to give me some pointers. Working for MPYD is my dream job. But the hull has already been cut and almost ready for the vacuum bag, so he will have to wait for Blake Hull #2 :(
     
  9. rwatson
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    rwatson Senior Member

    You dont use Gelcoat on models, you paint them. Its lighter, and you need all the weight savings you can get with this scale

    In full size boats, Gelcoat and Epoxy are not used together.

    The optimal weight model boat is built using 3mm high density foam sheet, covered in lightweight fg on both sides, not solid glass.

    Its not too late to do that. Pin the flat foam on your polystyrene mould, then glass them with 6 oz fg and epoxy.

    Pull them of the foam mould, and do the same with lighter fg scrim on the inside.
     
  10. NeverYachtz
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    NeverYachtz Junior Member

    I am not quite sure what you mean that gelcoat and epoxy are not used together. I thought gelcoat is sprayed into a mold before the epoxy and glass/carbon combination is laid up. Is that not how gelcoat works?

    The boat is model size, but it could see speeds of 60 mph or more if I dial the cg and props right. From what I have heard from other r/c boaters, 4-6 layers of carbon is the minimum for a boat capable of those speeds.

    Here is a boat running similar power, and dialed in perfectly. It's one of my favorite r/c videos due to the crazy speed, and I love Silverhook's design.

    http://www.youtube.com/watch?v=lEUjcYyuqgI&list=FL_tcTLSKehV3Qvdk7z13p0g&index=6
     
  11. rwatson
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    rwatson Senior Member

    Thats how gelcoat workes with Polyester resin, but its rarely if ever used with Epoxy. Gelcoat is a heavy layer designed to help non-waterproof Polyester resin cope with immersion. Its heavy, non structural and a waste of time on a boat this size.

    " 4-6 layers of carbon" is meaningless unless you specify the weight of the fabric. I think you have been fed a line

    here is advice i have found on RC World that expresses my experience

    "It depends on how the carbon fiber is utilized. Many manufacturers just simply replace a few layers of standard glass with carbon fiber in a wet layup system which does little as far as offering the properties available in a post cured pre preg epoxy laminate. I have seen some pretty high end builders just drop the final layer of glass and replace it with a 2X2 twill weave carbon (which is generally a cosmetic product) and state some kind of "I beam" advantage (BS). Having a boat constructed in carbon fiber can certainly be a big plus but a lot of the advantages can be lost in the process when building a pleasure boat. Find out how they plan to integrate the carbon into the schedule and if it will be post cured. Dont confuse the carbon fiber used in the aerospace/aircraft industry with carbon used in the marine biz. These are laminates that are autoclave cured and carry strength and tensile properties unobtainable in a wet bag system. Carbon is certainly cooler and has a higher "gee-whiz" factor but i sometimes wonder if its really that much better then a well thought out properly bagged S glass layup in the real world ......"


    The need to do vacuum bagging may also be a time sink, as this size of build may be just as good using peelply to optimise the resin/glass ratio.
     
  12. michael pierzga
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    michael pierzga Senior Member

    Boat looks great.

    In winter model enthusiasts race speedsters around the harbour basin. These boats are very fast.

    Ive never seen carbon in these models ?

    They appear to be.... from outside skin... a layer of lightweight CSM, a layer of lightweight uni directional eglass and a layer lightweight eglass cloth with model aircraft type plywood longitudinals, transom and bulkheads .

    Perhaps Gran Prix jobs are more sophisticated
     
  13. liki
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    liki Senior Member

    Could be wiser - and easier - to use kevlar instead of carbon.
     
  14. rwatson
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    rwatson Senior Member

    I dont think either are required. Simple S glass is way more than adequate. It might be fast, but its very light.
     

  15. NeverYachtz
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    NeverYachtz Junior Member

    Sorry I didn't mention the type earlier. It's 2/2 twill 3k.

    The reason I envisioned using this material from the start was due to an airplane I helped build with the aerospace club on campus. We used 1 layer of this fabric, with a thin layer of fg inside. Vacuum bagged, no post curing. The plane ran off the runway and hit a metal pole at about 20 mph. Didn't damage it one bit.

    So for the boat I figured I would do 2 layers of the cf for some exterior impact resistance, and reinforce it with fg behind that. No reasoning other than I've seen that configuration work well before. However I do appreciate the ideas and will look into some of them as well.

    And thank you for the info on gelcoat, I totally forgot it's just used with polyester. It's definitely better to just lay up the epoxy and then paint it once the boat is all put together. I wanted to get experience with gelcoat, but I guess I'll save that for another project.
     
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