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Need source for very quiet motors and omni wheels — Parallax Forums

Need source for very quiet motors and omni wheels

W9GFOW9GFO Posts: 4,010
edited 2012-12-24 09:51 in Robotics
I have been tasked with putting together a small robot that operates as quietly as possible. Silent would be ideal. I'm looking for some input as to which are the absolute quietest running gear motors. They need to be small: 20 to 50 oz-in torque and run about 120 rpm.

I have also been trying to find some small omni wheels. The problem is that they all seem to have either plastic or hard rubber rollers. If someone could point me to some 40 to 50 mm dia. omni wheels with soft rubber or foam rollers I would be very grateful.

Comments

  • Roy ElthamRoy Eltham Posts: 3,000
    edited 2012-12-22 23:02
    These aren't cheap and they aren't omni wheels, but mecanum wheels which might work for you: https://www.sparkfun.com/products/10543
    Those are semi soft rubber rollers, you'll need to do a little extra gluing or something to make them really stay together well, but they work decently enough.

    Not sure how you are going to get small motors that are also quiet. Usually small equals loud in my experience with motors. The big worm worm gear motors parallax sells with the 12v wheel/motor kit are super quiet... probably way too big though.

    Roy
  • W9GFOW9GFO Posts: 4,010
    edited 2012-12-23 00:36
    Yeah, I've seen those. Too expensive, and I need a three wheel omni anyway. Those Parallax motors at 1/4 the size would be ideal!
  • Roy ElthamRoy Eltham Posts: 3,000
    edited 2012-12-23 00:48
    I have a bunch of the different motors from pololu, when I get back next weekend I can do some sound tests on them for you. I suspect they will all be too loud, but we shall see.
  • ercoerco Posts: 20,256
    edited 2012-12-23 07:55
    Those Sparkfun wheels are pure Smile, do not consider them. Kornylak (?) makes some small omniwheels with a variety of plastic and rubber rollers. Google them.

    Motor mounting (rubber) and chassis design & material might be more important than motor selection, noise-wise.

    So who are you trying to sneak up on? :)
  • ercoerco Posts: 20,256
    edited 2012-12-23 08:16
    Robotshop has many omniwheels, some down to 40mm.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-12-23 10:44
    Compared with Vex's Mecanum wheels those FingerTech wheels are very disappointing (I have a set of each).

    Rich, I'd be surprised if you don't know about Vex's omni wheels. They use the same green rubber on the omni wheels as they do on their Mecanum wheels. I'm guessing this isn't soft enough for your needs. I've used their 4" wheels, they also have some nice 2.75" omni wheels. I'm guessing they're too big and too hard.

    One of our forum members pointed out these omni wheels. I'm not sure if you (Rich) have seen them.

    Roy, you need to get yourself a set of Vex's Mecanum wheels. They're much nicer than the FingerTech wheels. Have you seen Rich's robot with the Vex Mecanum wheels? (It's very cool.)
  • W9GFOW9GFO Posts: 4,010
    edited 2012-12-23 11:08
    I have looked into the Kornylak wheels. Problem is that the smallest ones do not have soft rubber rollers. I have doubts that I will find a small omni with soft rollers. Since their primary purpose is material handling it wouldn't make sense to mass produce them with soft rollers that would wear out quickly.

    @Duane, We have tons of those Vex wheels at the robotics club. I need them to be less than 60mm diameter so that leaves out all of the Vex offerings.

    @Roy, thanks, that will be helpful. I've been doing the same thing here but my selection of small motors is pretty unspectacular.

    @erco, it will be moving in a very quiet environment where audio is being recorded, no sneaking. Nothing earth shattering - but my customer would not appreciate me talking about it.
  • Roy ElthamRoy Eltham Posts: 3,000
    edited 2012-12-23 11:28
    Duane,
    I already have a set of the Vex ones, and yes, I saw Rich's bot with them at the expo.

    erco,
    Yeah they are kind of Smile, but I was able to make them function, and they were fairly quiet. They come apart if you just leave them press fitted together, but some glue would solve that. I definitely wouldn't put them under heavy load either.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-12-23 11:35
    Rich,

    I have code for controlling a three wheeled omni bot, so if your robot is going to use three wheels and you'd like to see/use my code, let me know.

    I wonder if you'd have better luck finding a quiet motor/gearbox, if you use a motor with much more power than you need and just run it slow? (Just a guess.)
  • PMAC57PMAC57 Posts: 1
    edited 2012-12-23 11:54
    For a quiet wheel with soft rollers you might try http://www.hitechnic.com/cgi-bin/commerce.cgi?preadd=action&key=HRC2148 or http://www.rotacaster.com.au/shop/category/cat10325/Rotacaster_Robotic_Wheels_Lego_NXT_Compatible.html. Kornylak sell the the industrial version but without a hub insert. Depending on selected motor you could modifiy or make a 0.5" keyed hub to suit fairly simply.
    Peter
  • CrazyrabbitCrazyrabbit Posts: 116
    edited 2012-12-24 06:15
    Just an idea. I got a Wow Wee Rover from ebuy. Works good except it eats batteries and won't dock. It does have 3 excellent omniwheels and motors to hack. It even goes sideways on medium carpet.
  • prof_brainoprof_braino Posts: 4,313
    edited 2012-12-24 09:51
    3d printable omni wheels from our old friend Cliffe Biffle

    36mm Omniwheel

    http://www.thingiverse.com/thing:705
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