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Wheels with a 1/2" (13mm) hub? — Parallax Forums

Wheels with a 1/2" (13mm) hub?

MarkSMarkS Posts: 342
edited 2007-10-01 13:15 in Robotics
I want to build a robot for my nephew. He loves robots and this could be fun for both of us. I've settled on the BaneBot 42mm gear motor from Trossen Robotics, but I cannot find a wheel or hub that supports a motor that size and they couldn't answer that question when I called. I need a wheel no more than 6" OD x 2.5" wide.

Any ideas?

Comments

  • Ken GraceyKen Gracey Posts: 7,392
    edited 2007-09-07 22:37
    Hello Mark,

    Pending completion of our electronics, we're about to release a complete motor and wheel mount package:

    http://forums.parallax.com/showthread.php?p=654636

    The wheels have a 1/2" hub ID, 7" OD and about 1.25" wide.

    Our system is best used with the motor, bearing block and wheel that we provide.

    Ken Gracey
    Parallax, Inc.
  • MarkSMarkS Posts: 342
    edited 2007-09-07 22:43
    Actually, that's not bad. When will you have some engineering drawings ready? I'm building the bot around the motors/wheels, so I need detailed drawings of the drive system. Is it still going to be about $199 for a pair? I've been following that thread, but forgot about it when I started looking today. I'm looking to start the build in about a month, so hopefully you'll have them ready by then.
  • DgswanerDgswaner Posts: 795
    edited 2007-09-09 07:23
    Home Depot sells lawn mower wheels, which have a 1/2 diameter hub, the problem with them is connecting it to the shaft.

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  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2007-09-09 10:40
    The best deal ever is bicycle training wheels. Very cheap compared to all else and appropriately sized.· These are 5" OD and· freeturning 1/2 shaft.

    Industrial wheels are expensive if bought separately. But if you buy a hand truck [noparse][[/noparse]maybe at a garage sale] and remove the wheels, you have a bargain.

    Broken wheel barrows are good too. But where do you get 4 of them?

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    "Everything in the world is purchased by labour; and our passions are the only causes of labor." -- David·Hume (1711-76)········
    ···················· Tropically,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan

    Post Edited (Kramer) : 9/19/2007 9:15:35 AM GMT
  • Joe "Bot" RedJoe "Bot" Red Posts: 81
    edited 2007-09-10 01:51
    Similar to Kramer's idea... I found Stroller wheels great, they are light and rugged, with pretty good traction. I have been lucky to find a few in the trash, but you can look at craigslist.org there are always posts in the free section...

    I hope this helps... happy roboting!
  • StampNut2StampNut2 Posts: 224
    edited 2007-09-10 06:08
    Ken: Could you let me know what it would be to send a pair to NZ.

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  • slashsplatslashsplat Posts: 63
    edited 2007-09-23 01:19
    Wheels at
    www.allelectronics.com/
    search for
    wheels 6"
    and they are $1.50 or so with a 9mm hole. I have some and they are hard rubber, narrow, but VERY functional on hard surfaces. They also have multiple sizes. See WH-17 and WH-17 parts. The hole can be drilled to size.

    Tower has a pair of 6" strong foam wheels, great traction, for $16.75 www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXB934&P=7 that fit a 4mm shaft, but can be drilled to larger axles.

    Neither types of wheels have any locking mechanism included - slot, key, setscrew...

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  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2007-09-23 10:16
    The nice thing about the trainer wheels is that they are heavy plastic, not steel hubs.

    For the DIYer, one can easily epoxy them directly to a drive shaft or create brass or plastic inserts to make the shaft smaller. They have a solid rubber tread for traction. I think one could even leave them freespinning and easily mount a steel chain drive sprocket. In this way, a higher RPM motor could be geared down and you could get higher chassis clearance at the same time. The teeth in a sprocket might even work as a source for a DIY encoder to count RPM.

    In most cases, true pneumatic wheels and steel hubs are intended for hefty weight - over 70 lbs or more. The trade off is that they also add weight and are more difficult to drill and modify. Many have built-in ball bearings that render them useless for direct connection to a drive shaft.

    So if you are planning a 30 pound robot, you don't really need to be than beefy. You can save time and money.

    Wheels with a square shaft keyway are intended for high toque, usually gas engines, chains, and gears. In other words, if you want to drive them with multiples of horsepower. That is going to be a heavy electric motor and heavy battery, unless you are going to something like Parallax's Hybrid that generates electricity from a 1HP gasoline engine to a MINI alternator.

    Again that is okay, if you want that - but it usually means finding motors with matching keyway or having a local machine shop mill a keyway into an existing shaft. Of course, you can ignore the keyway, hope that the setscrews will do it all, and live with potential slippage.

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    "Everything in the world is purchased by labour; and our passions are the only causes of labor." -- David·Hume (1711-76)········
    ···················· Tropically,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan
  • Jan EJan E Posts: 11
    edited 2007-10-01 13:15
    Hello Ken,
    You are about to release... Yes but when? I need them...
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