Results 1 to 7 of 7
  1. #1
    Senior Member
    Join Date
    Feb 2008
    Location
    Boston, MA
    Posts
    549
    Thanked: 124

    Default $15 Grinder Project

    Grinding with a coarse whetstone has got to be the world's most tedious activity, and I wasn't very far at all into my utility knife making project when I got tired of it and decided to build the fabulous feat of redneck engineering you see here. My original intention was to cut up the frame and arrange it so I can pedal with my feet, but it seems to work OK so far turning it by hand. Total cost; $15 for the bicycle at the thrift store.

    The disc is a standard angle grinder disc, whose hole is the perfect size to accept a skateboard bearing. The spacer is a skateboard wheel bearing spacer, and the bolt is a 5/16" UNC bolt (standard skateboard axle size).

    I cannibalized the sprocket off the rear hub of the bike. I used hot glue to secure both the wheel bearing and the sprocket, but the sprocket attachment didn't last, so I'm going to have to come up with something better.

    Edit; for the record, I mean no disrespect to the rednecks, on the contrary, I admire their resourcefulness & their ability to do a lot with a little, as ought to be evident by my imitation.
    Attached Images Attached Images     
    Last edited by Johnny J; 10-17-2010 at 11:18 PM.

  2. The Following User Says Thank You to Johnny J For This Useful Post:

    Shoki (10-17-2010)

  3. #2
    Senior Member Shoki's Avatar
    Join Date
    Sep 2010
    Location
    Los Angeles, CA
    Posts
    553
    Thanked: 179

    Default

    You might be a redneck if...

    Awesome contraption!

  4. #3
    Senior Member TrilliumLT's Avatar
    Join Date
    Oct 2010
    Location
    Everett, Ontario
    Posts
    1,500
    Thanked: 298

    Default

    Awesome. I love it.

  5. #4
    Senior Member blabbermouth Geezer's Avatar
    Join Date
    Jul 2010
    Location
    EauClaire,WI
    Posts
    6,105
    Thanked: 2734
    Blog Entries
    1

    Default

    YeeHa~
    respectfully
    ~Richard
    "There's a fine line between hobby and mental illness." - Anon.

  6. #5
    Admin & Forum fixer Bruno's Avatar
    Join Date
    Nov 2006
    Location
    Belgium
    Posts
    13,812
    Thanked: 3982
    Blog Entries
    9

    Default

    This is a novel idea
    And instead of the grinding disc, you could use a contact wheel or a drum, and make adecent belt sander. Bicycle frames + bearings are a dime a dozen (or rather, for free at the recycling center)

    And perhaps an electro motor for the drive ...
    Happiness is a field, littered with the mangled corpses of your enemies. - Vlad III of Wallachia

  7. #6
    Senior Member
    Join Date
    Feb 2008
    Location
    Boston, MA
    Posts
    549
    Thanked: 124

    Default

    I put the sprocket back on with plumber's epoxy & have been using the grinder. It's maddeningly slow due to the low RPMs. The right way to do this would be with a variable speed motor. A bicycle derailleur seems like an appealing way to get adjustable speed, but I'd be leery of working around a device where chains & sprockets are being driven by an electric motor. There have been quite a few finger amputations caused by fixed-gear bicycles.

    Edit: in the end, I am forced to declare this a failure. The grinder definitely works, but when you put things together in this cheesy way (e.g. epoxy instead of screws) it works for a little while, then it breaks. My ability to build things is definitely being hampered by my inability to machine real parts.

    The idea of a hand-crank grinder, however, is far from absurd. Even with the setup you see here, it's easy to overheat the metal. I'm tempted to try to build a hand-crank grinder where the wheel rotates in water, with no gearing at all. I'd have to find a local machine shop that can make the parts that I'm unable to make.
    Last edited by Johnny J; 10-18-2010 at 08:41 PM. Reason: More info

  8. #7
    Senior Member blabbermouth nicknbleeding's Avatar
    Join Date
    Oct 2009
    Location
    Springfield,Ma
    Posts
    3,083
    Thanked: 1275

    Default

    I dont know how old you are but if you have children flip the bike over. Make a brace, and have your kids power it for you. Child labor is the last of the untouched resources

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •