3D printed in-frame plastic gas tanks

Discussion in 'Motorized Bicycle Welding, Fabrication and Paintin' started by KCvale, Nov 24, 2014.

  1. KCvale

    KCvale Active Member

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    I am a couple of months into creating a 3D CAD file to make plastic gas tanks that fit common beach cruiser bikes frames, have the base design .STL file and sent it to this Purple Porcupine rapid prototyping service and got this quote back to make 1 gas worthy gas tank to fit a 29" Macargi.

    [​IMG]

    So much for prototyping with the right material.

    $6,816.78 to print out one tank.
    Total does not include tax and shipping.

    I guess I shouldn't have said I was from NASA? hehe ;-}
     
  2. MotoMagz

    MotoMagz Active Member

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    That price isn't bad...after all the tooling is done the product price is cheap.Just the start up cost is what stops people really quick! Its very hard to get that start up cost back and then make any profit.
     
  3. MotoMagz

    MotoMagz Active Member

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    Those are so cool I saw a car they built with a huge 3d printer.$600 that's cheap for what they can do.
     
  4. atombikes

    atombikes New Member

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    It's the media that is expensive. This process is called "additive machining" btw.
     
  5. Harold_B

    Harold_B Member

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    Likely a big difference between the quoted part and what can be made on those little machines. The printer max space is 7.8" square meaning you'd have to print the tank in sections and glue them together. Not the end of the world but worth noting. The resolution of the $600 printer is nominal .010" with layer thickness at .020". Plan on spending some time with solvent and sand paper to get a smooth finish. I'm not at all sure about the material specs and compatibility with fuel but again worth noting in the price.
     
  6. Rudz

    Rudz New Member

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    Can you sell a hundred tanks at 70 bucks each? Maybe, but it will take a while.
     
  7. Desert Rat

    Desert Rat New Member

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  8. Dan

    Dan Staff
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    That's a great point, Rudz. And that's at prototype costs.

    ==========================================

    Guessing the potential customers are, for the sake of discussion 100,000 globally.

    That makes the break even point .001 of the market/sales.

    Even half that to be properly conservative is a really promising projection.

    But projections are just day dreams with supporting documentation. LOL, or the "Executive Summery" in a business plan......
     
  9. KCvale

    KCvale Active Member

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    That's just it, there is no tooling in 3D printing, I am supplying the .STL CAD file of printing instructions.

    The expensive part is the material, there are only a couple of Polyethylene plastic (HDPE, MDPE) that get a B grade for gas and
    STRATASYS says PPSF / PPSU (Polyphenylsulfone) is the gasoline-resistant 3D-printing medium you need:

    http://www.stratasys.com/~/media/Main/Secure/White Papers/Rebranded/SSYS-WP-Thermoplastics-03-13.pdf (scroll down to the last material)

    That means a special large 3D printer to handle it and apparently it's not cheap.

    I do have the option to have a mold made from the .STL and then have them injection molded, but again I'd need to make to make a couple hundred just to break even.
     
  10. Ludwig II

    Ludwig II Well-Known Member

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    #11 Ludwig II, Nov 25, 2014
    Last edited: Nov 25, 2014
  11. KCvale

    KCvale Active Member

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    Thanks Ludwig, I'll see what I can find, I also contacted a local injection molding place that looks promising with their services.

    http://www.4frontmfg.com/services.htm

    Even in an 'instant' world, some things still take a long time to see happen.
     
  12. Imthegrt1

    Imthegrt1 New Member

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    Sounds like a great idea seems like it should sell.
     
  13. Ludwig II

    Ludwig II Well-Known Member

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    There's also hydro forming, for those python-swallowed-the-baby expansion chamber shapes. It requires no heavy investment in plant, but there's more work involved in total to make a tank.

    http://www.eurospares.com/frame8.htm
     
  14. KCvale

    KCvale Active Member

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    All I care to do is sell enough to cover development costs and have a supply for my own builds.

    I am playing with some templates for something I can do in metal for flat base pieces and then see what I can do to soften the lines to fit the beach cruisers flowing lines.
     
  15. Harold_B

    Harold_B Member

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    Apparently not cheap would be an understatement compared to the prototype you were quoted. We have one of the small Mojo printers in our office capable of printing with the ABSplus material. It is a demo unit and was about $10K.
     
  16. joey1320

    joey1320 Member

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    You can find local 3d printers who would make this type of project for a fraction of that quoted cost. I found a few printers on Craigslist but I have never designed anything like this so I would have to pay for the designing too.
     
  17. Ludwig II

    Ludwig II Well-Known Member

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    The other solution is to make fibreglass tanks in two halves. The initial cost would be fairly low, but then it becomes labour intensive after that, and that costs money if someone else is doing the work for you.

    As a money making hobby, though, it would get you out of the house and into the workshop.
     
  18. Ludwig II

    Ludwig II Well-Known Member

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    I keep getting reminded of things. Blow moulding is one. You can have lots of shapes, but the surface finish is never very good. What about a simple, perhaps ready made, tank and a separate cover, styled to suit different frames?

    [​IMG]
     
  19. KCvale

    KCvale Active Member

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    Well ya, $6,800 to print out one tank is beyond outrageous.

    I am waiting on a quote from another local guy that does form and roll molding as well as dip molding but then there is the tooling for the mold.

    Now I can see paying $1-2K for tooling a mold good for 100 units or so, but that's another rub, how long the mold will last, they can be made from many different substances from 1 time use to hundreds of uses to thousands of uses each costing more because of the material it is made of and the cost to tool it.

    More as I learn more as this is all new to me.
     

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