Free 173 Best Homemade Tools eBook:  
Become a founding member: 500+ tool plans, full site access, and more.

User Tag List

Results 1 to 10 of 10

Thread: Wood chipper - video

  1. #1

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

    nova_robotics (May 6, 2021)

  3. #2
    Supporting Member
    Join Date
    Sep 2018
    Posts
    392
    Thanks
    1,550
    Thanked 96 Times in 77 Posts

    nova_robotics's Tools
    That thing scares the poop out of me. The fasteners aren't captive. Run that for 15 seconds and the bolts are going to back off. That's when you catch one of those sharpened blades in the forehead.

  4. #3

    Join Date
    Jul 2017
    Location
    Waimauku NZ
    Posts
    35
    Thanks
    18
    Thanked 32 Times in 14 Posts

    Daturat100r's Tools
    Helluva dangerous it will smash itself to pieces with failure to chip limit as well as what Nova pointed out. Industrial chippers use and anvil and blade that cuts all but flush with anvil so the feed controls the chip size.This thing, before it spits its blades out will grab a huge bite and drag the wood at a speed close to or equal to knife tip speed.Terrifying really would not want to be anywhere near it

  5. #4
    Supporting Member schuylergrace's Avatar
    Join Date
    Sep 2020
    Posts
    12
    Thanks
    7
    Thanked 4 Times in 2 Posts
    All the extra effort to cut slots in the blade blanks, when they would have been much safer and just as easy to install with the original clearance holes for the attachment screws. And I'd also put thread locker on the bolt threads and safety wire them to make sure they don't back out. Just one of those bolts could put a serious hurting on a fellow if it came flying out. At least a blade coming off would require failure or loosening of three bolts. I'm assuming, at this point, the feed issues have been worked out, but we'll see in the next installment.

  6. #5
    Supporting Member NortonDommi's Avatar
    Join Date
    Jul 2014
    Location
    North Island, New Zealand.
    Posts
    523
    Thanks
    1,169
    Thanked 288 Times in 177 Posts

    NortonDommi's Tools
    Common in Much of Europe. https://remetcnc.cz/141-rezaci-mechanismus/ is just one manufacturer. If you want to make one that works better here is a Rebak Wolcowy from your own hands: https://chertegnik.ru/oborudovanie/5...chertezhi.html
    If you plug Rebak walcowey into YouTube you will see everything from professionally manufactured to barely together grenades waiting to go off.
    The types of burners used demand smaller pieces. These things process wood very fast but regardless of the diameter of the cutting circle chip length varies depending on wood diameter.

  7. #6
    Supporting Member
    Join Date
    Feb 2021
    Posts
    2
    Thanks
    0
    Thanked 0 Times in 0 Posts
    What kind of cut-off wheel are you using on your angle grinder? It's very impressive!

  8. #7
    Supporting Member
    Join Date
    Nov 2017
    Posts
    166
    Thanks
    7
    Thanked 94 Times in 53 Posts

    Math

    Quote Originally Posted by Daturat100r View Post
    This thing, before it spits its blades out will grab a huge bite and drag the wood at a speed close to or equal to knife tip speed.
    The comparable one NortonDommi linked to runs at 540rpm. Assuming that the diameter of the rotor is 3 inches that puts the knife tip speed at 20 feet per second* or 13 miles per hour. A broomstick shoved through it and shot out at that speed It would certainly hurt, but it's not likely to fly very far.

    * Double-check that math: 3 inch diameter squared is 9 times 3 (pi) = 27 inches per rotation * 540 rpm = 14580 inches per minute /60 = 243 inches per second /12 = 20.25 feet per second * (3600 seconds per hour/5280 feet per mile) = 13.8 miles per hour.

    As it's feeding wood through the blade is being shoved back onto the bolts, so for knife ejection to happen it would have to snap all three of the retaining bolts. I don't know enough engineering to know if that's a likely failure scenario, but for scale the single shear strength of a grade 8 1/2" bolt through 1/2" material is a several tons. Your scenario of it grabbing the wood and pulling through seems more likely, but it would require all of the blades to be too loose to cut through the material at the bottom of the cutting cycle. This seems like it would get more likely over time as the middle of the blades started to wear.

    Here's hoping they put an E-stop bar on the feed-in. An arm stuck in that would be horrific.

  9. #8
    Supporting Member
    Join Date
    Nov 2017
    Posts
    166
    Thanks
    7
    Thanked 94 Times in 53 Posts

    Wink

    He finished it, and it's every bit as terrifying as you could imagine. No E-stop, spinning terrifying fast, and yeeting out foot-long vampire killers out the back.


  10. #9
    Supporting Member
    Join Date
    Sep 2018
    Posts
    392
    Thanks
    1,550
    Thanked 96 Times in 77 Posts

    nova_robotics's Tools
    Quote Originally Posted by Elizabeth Greene View Post
    He finished it, and it's every bit as terrifying as you could imagine. No E-stop, spinning terrifying fast, and yeeting out foot-long vampire killers out the back.
    Can you submit a Youtube link as part of a coroner's report?

  11. #10
    Supporting Member schuylergrace's Avatar
    Join Date
    Sep 2020
    Posts
    12
    Thanks
    7
    Thanked 4 Times in 2 Posts
    To be fair, and e-stop would probably just prolong the agony. Might as well get sucked all the way in and get it over with.



    173 Best Homemade Tools eBook

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Bookmarks

Posting Permissions

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