small prototype engine with bearings

Discussion in 'My Work In Progress' started by BluesRocks, Aug 28, 2009.

  1. BluesRocks
    BluesRocks Member
    Help
    I'm seeking help with drive shaft bearings for my new compressed air engine/turbine design. I've seen youtube vids of 3D printed plastic bearings. But maybe I'd be better off with buying off the shelf bearings. Have you printed functional bearings? If so, what are the functional limitations and long term wear issues?

    Engine/Turbine
    It will be about 4x4x5" with numerous 3/8" drive shafts delivering about 1/3 horsepower. Just enough to drive 300lbs of bicycle and cyclist about 25mph on a flat road. I can't really disclose the working design without giving away most of the entire idea.

    Modified Drawing
    Maybe I could offer a modified drawing to illustrate what I'm dealing with. What sorts of file formats do you accept? I use Solidworks mostly, but also have Sketchup and TurboCad. I'll try to host a doc somewhere and see if I can link to it here.

    Off The Shelf
    Maybe I should buy off the shelf bearings (the shafts need to spin without vibration, tight tolerances) and gears and just build the rest of the engine/turbine in plastic.
     
  2. 21170_deleted
    21170_deleted Member
    Greetings!

    I would say real bearings. I make allot of widgets for RC cars and trucks and the such and I routinely design for Bearing mounts in my models. A printed bearing, even if precisely designed and crafted, would still be made out of a polymer (Plastic) . So it would wear quickly and get that vibration that you are trying to avoid. And metal bearings are very reasonably purchased if bought in bulk.
     
  3. Dalhimar
    Dalhimar Member
    Well i would say your optimal choice would be to use premade bearings. Though for small prototypes you can use the printed, they use a nylon type plastic which though durable, will not be good for long term use. Though now that shapeways offers metal printing, you could try that but i can garuntee that the surface will be no where as flawless as the premades you can purchase for cheaper. The metal printing is somewhere around 10 USD per cubic cm if i remember right, so yea... just do the math for it and it should become pretty clear =P