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Ebay China Mecanum Wheel — Parallax Forums

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  • pmrobertpmrobert Posts: 677
    edited 2018-11-07 17:33
    The Honda tech writer must have moved to China!
  • Haha, nice find. Have you used anything like that? I feel it would get hung up a lot on anything but a smooth surface.
  • kwinnkwinn Posts: 8,697
    pmrobert wrote: »
    The Honda tech writer must have moved to China!

    LOL, brings back memories of setting up PC clone boards from a chinglish instruction sheet.
  • Heater.Heater. Posts: 21,230
    edited 2018-11-08 15:53
    On the first page of the repair manual for my Yamaha back in 1975 it advised that:

    "Repair of Yamaha motorcycle require great piece of mind".

    Advice that has held me in good stead for tackling any job since.

    I suspect it's where Robert M. Pirsig got his inspiration from !


  • kwinnkwinn Posts: 8,697
    Heater. wrote: »
    On the first page of the repair manual for my Yamaha back in 1975 it advised that:

    "Repair of Yamaha motorcycle require great piece of mind".

    Advice that has held me in good staid for tackling any job since.

    I suspect it's where Robert M. Pirsig got his inspiration from !


    Once more a post on this forum has caused me to go to Google Search. Surprising how often that happens. I did purchase and read the book in the late 70's, but by that time my motorcycling days had been over for a number of years. Not a practical means of year round transportation where I live. Miss it at times though.
  • Heater.Heater. Posts: 21,230
    Pirsig's book is not actually about motorcycle maintenance. Which was a disappointment because I was much into motorcycles at the time. Not sure it's even about Zen much. Also a disappointment.

    It was hugely famous back then so I tried reading it. Didn't get the idea and gave up half way through. Seemed like some ramblings of a lunatic.

    Perhaps I should try again.

  • kwinnkwinn Posts: 8,697
    Heater. wrote: »
    Pirsig's book is not actually about motorcycle maintenance. Which was a disappointment because I was much into motorcycles at the time. Not sure it's even about Zen much. Also a disappointment.

    It was hugely famous back then so I tried reading it. Didn't get the idea and gave up half way through. Seemed like some ramblings of a lunatic.

    Perhaps I should try again.

    The book title and the fact that I bought and read it is the only thing I can recall now so I guess I didn't get any great insights or inspirations from it either. Probably wondered what all the fuss over the book was at the time.
  • Pardon me, but what is a “mecanum wheel”?
  • Pardon me, but what is a “mecanum wheel”?

    https://en.wikipedia.org/wiki/Mecanum_wheel
  • The mecanum wheel is an improved version of the omni wheel, which was invented by Josef Blumrich in the course of interpreting the Biblical book of Ezekiel as an encounter with a spacecraft, one equipped with wheels that could move in any direction. And the omni wheel was featured as the tail dragger wheel on one other than the Parallax Stingray differentially steered robot.
  • W9GFOW9GFO Posts: 4,010
    edited 2018-11-09 03:06
    Pardon me, but what is a “mecanum wheel”?
    https://www.youtube.com/watch?v=_f_x0RgVzfc

  • ercoerco Posts: 20,257
    xanadu wrote: »
    Haha, nice find. Have you used anything like that? I feel it would get hung up a lot on anything but a smooth surface.

    Very true. I see a lot of "ball casters" used on robots large and small. But as our good forum friend and author the late Gordon McComb pointed out numerous times, these are designed to run upright, per the image. Only in this orientation (borientation, Toby) do the small internal balls actually roll and recirculate. When you invert it to use as a caster, all the balls fall away and there's massive internal friction and often the big ball just skids along instead of rolling. For many surfaces, you might as just glue or weld the big steel ball on and let it slide, essentially a larger radius version of this cap nut "mecanum wheel".

    ballcaster.png
    600 x 600 - 56K
  • WhitWhit Posts: 4,191
    erco wrote: »
    Very true. I see a lot of "ball casters" used on robots large and small. But as our good forum friend and author the late Gordon McComb pointed out numerous times, these are designed to run upright, per the image. Only in this orientation (borientation, Toby) do the small internal balls actually roll and recirculate. When you invert it to use as a caster, all the balls fall away and there's massive internal friction and often the big ball just skids along instead of rolling. For many surfaces, you might as just glue or weld the big steel ball on and let it slide, essentially a larger radius version of this cap nut "mecanum wheel".

    @erco - you could always just run the robot on the ceiling.

  • WhitWhit Posts: 4,191
    @erco - When you say gaster nut, I assume you are talking about the same thing as a crown nut or acorn nut - is that correct? What they call a "Mecanum Wheel" is really just a skid, right?
    321 x 125 - 30K
  • WhitWhit Posts: 4,191
    But the way, if we are going with a traditional erco all wood bot, you could just glue on a real nut.
    600 x 433 - 83K
  • Whit wrote: »
    But the way, if we are going with a traditional erco all wood bot, you could just glue on a real nut.

    Brilliant, Parallax could sell Walnuts, not Hazelnuts. All made in the US of A.

    The Parallax mecanum Walnut caster. @"Ken Gracey" a new venture on the horizon...

    Mike

  • YES! My VEX robot for school uses these! my classmates give me Smile because VEX makes an octagonal Holonomic Robot Kit using these "Mechanomic" wheels.
  • @erco Yes. The 'half ping pong ball' method worked better than the inverted metal ball casters as well. I have a box of 100 ping pong balls. That means I own 200 Mechanum wheels haha.
  • Erco,

    Have you see Dave Jones' video on the "Mad" 1 cent regulators?
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