I need a small hydo-turbine

Discussion in '3D Design Requests' started by HawaiiUAV, Nov 20, 2013.

  1. HawaiiUAV
    HawaiiUAV New Member
    Here are the parameters:

    * An inlet and exhaust that is threaded with some standard size fitting I can buy pieces for at the local hardware store.
    * It needs to hold high PSI, enough to get the RPM really high to say maybe 6,000 RPM or greater.
    * It needs to be fitted with a shaft.
    * It will need to be air tight.
    * Roughly 1.5 inches diameter
    * Hydro (water) powered

    I don't know if there is already a design out there? I'm curious if anyone knows how to engineer this not just to make it work but make it work as efficiently as possible.

    I'm looking forward to feedback from you the expert(s) :)

    Last edited: Nov 20, 2013
  2. I hate to put a damper on anyone's enthusiasm for innovation, but...

    It is illadvised to use any 3D printing material for any pressurized item. These are NOT engineeried materials. Printing of the impeller or inserts for shaft bearing mounts might be ok, but all pressure containment bodies should be considered out of bounds. I would suggest that this includes bronze and brass prints. Yes, brass fittings are available at the hardware store and are pressure rated, but these parts are manufactured under the governance of strict engineering controls and governing bodies, including audited quality control systems. Even civic water supply pressures are too high to risk playing with. If the cessel is completely filled with water, a rupture is merely an annoyance. If there is trapped air, however, you have created a small bomb whose casing may become shrapnel.

    If you do get an impeller printed, please be sure to have it balanced - preferably dynamically balanced, but statically balanced at a minimum - as anything expected to spin at 6,000rpm will be subject to significant centripetal forces at that speed.
  3. HawaiiUAV
    HawaiiUAV New Member
    Thx for your input but what about 3D printers that print in metal?
  4. Same deal. Pressure bearing items are manufactured under strict control. You might get away with it, but you might be making the cause of a lawsuit. Maybe.

    Cast materials are prone to porosities, inclusions, and other flaws. Cast plumbing items are scrtinized quite heavily in the manufacturing process compared to forged or machined components. The processes Shapeways are using to produce metal products are (as far as I've been lead to believe) NOT subject to such scrutiny. Generally speaking, these parts are intended to be "ornamental" in application, even if practical in design.

    For prototyping purposes, having a proper housing made should be reasonably inexpensive, as machining from bar stock should be fairly simple. No, it's not going to be as light and pretty as the final product, but it should give valid performance data otherwise. As I said previously, the impeller should be fine so long as it gets properly balanced. (Actually, 3D printing should be the cheapest way, short of mass manufacture, to make a turbine impeller.)

    I'm not saying it can't be done. If you do it, be sure to get the part examined and tested thoroughly prior to practical use.

    Hmm... in re-reading your post, perhaps you meant the DMLS process, as is used for making titanium parts? This may be a better alternative, but I'd still advise extreme caution and rigorous testing. Contact those who manufacture using this process and ask their advice on suitability of their technology in your application. Your mileage may vary.
    Last edited: Nov 20, 2013
  5. HawaiiUAV
    HawaiiUAV New Member
    I can have a machine shop build it but I still need the design. I'm not worries about law suites. This is just for me not for mass production.