Results 1 to 6 of 6

Thread: Scrap steel

  1. #1
    Join Date
    Jan 2016
    Location
    Wodonga Vic
    Age
    38
    Posts
    633

    Default Scrap steel

    I see a Clay Spencer power hammer in this pile of scrap

    What do you see?

    C24E957F-61D1-4465-A129-9943389C2299.jpg

    The round bar is 220mm diameter x 950 long, i milled the ends flat in case I do decide to lug it home and use it for a project. I think it’s 4150, I’ll have to look up the stock number and confirm.

  2. #2
    Join Date
    Jan 2016
    Location
    Wodonga Vic
    Age
    38
    Posts
    633

    Default

    In case anyone hasn't seen one, here's a pic of a Clay Spencer tyre hammer

    power hammer.jpg

    And now an electrical question for BobL;

    normally these hammers are powered by varying the friction of a constant running electric motor against the tyre flywheel, but I was wondering if ditching the tyre and using a 3 phase motor with a VFD would be a viable option? I'm thinking something like a modified sewing machine pedal for speed control.

    Cheers.

  3. #3
    Join Date
    Mar 2011
    Location
    Southern Flinders Ranges
    Posts
    1,536

    Default

    In theory possible, it would go in place of the variable pot you would normally use. Whether that works how you need it to may be a matter of some experimentation. My understanding of those tyre drives is you can unload the drive completely which won’t be possible with a VFD

  4. #4
    Join Date
    Nov 2017
    Location
    Geelong, Australia
    Age
    57
    Posts
    2,651

    Default

    A simple belt drive would allow easy drive disconnect.
    Either pivoting motor or a latching idler to release the belt tension.

    I’m guessing the tyre also acts as a flywheel, so you couldn’t just remove it completely without replacing it with something else.

    Steve

  5. #5
    Join Date
    Jan 2016
    Location
    Wodonga Vic
    Age
    38
    Posts
    633

    Default

    Quote Originally Posted by OxxAndBert View Post
    A simple belt drive would allow easy drive disconnect.
    Either pivoting motor or a latching idler to release the belt tension.

    I’m guessing the tyre also acts as a flywheel, so you couldn’t just remove it completely without replacing it with something else.

    Steve
    How come the need for total disconnect to the flywheel? With the top die at bottom dead centre it's still clear of the bottom die, would it be purely a safety thing?

    The plan was to ditch the large tyre for a smaller equally massed piece of steel (in abundance at work) and reduce the overall height of the hammer

    Ben

  6. #6
    Join Date
    Nov 2017
    Location
    Geelong, Australia
    Age
    57
    Posts
    2,651

    Default Scrap steel

    I hadn't actually looked at how they operate - was more just responding to racingtadpole's comment about not being able to get the complete disconnect with a VFD.
    Looking at a few videos of them in action - the hammer stops pretty much instantly when you take your foot off the pedal. There is a brake pad that is adjusted to press against the tyre as the drive is removed from it, but the drive needs to be removed first.

    To me, the tyre is an integral part of the design. You want to leave the motor running and control the engagement and speed with the pedal.
    You also need the jogging facility that it gives to be able to lift the hammer to insert the work or die etc, and the tyre diameter and rubber provides effective braking.
    A VFD and constantly engaged drive can't achieve it IMO - you need a clutch of some form.

    FWIW my Klopp shaper has a similar drive setup - a rubber drive wheel onto a flat metal one so effectively the reverse rubber/metal config as the hammer tyre drive. It has a normal friction lining style brake pad that engages on the output wheel to stop it.




    Its probably about 60 diameter rubber wheel, and 450 diam driven but I guess if you dropped the motor input speed with a VFD you could reduce that driven wheel. Reducing the driven wheel diameter means you need more brake pad pressure to achieve the same braking effect though. No free lunch I guess..

    Looks like an awesome project.

    While educating myself I found a couple of YT vids that others might enjoy.

    First is a hammer in action: https://www.youtube.com/watch?v=J1vi4pJxVWU

    Second is a group build of a bunch of them. Its a bit long, but shows a bit more construction and the brake setup. 18:13 shows one being run/tested and has a good view of the crankshaft action etc: https://www.youtube.com/watch?v=JfMckGW6kYs

    The hammer mechanism looks very similar to the "Little Giant" hammers (which seem to run conventional style clutches and brakes)

    Steve

Similar Threads

  1. The great scrap metal dealer Stainless Steel scam
    By bollie7 in forum METALWORK GENERAL
    Replies: 15
    Last Post: 7th Jan 2021, 10:44 PM
  2. Scrap !
    By BaronJ in forum METALWORK GENERAL
    Replies: 14
    Last Post: 28th Jul 2018, 11:59 AM
  3. Replies: 3
    Last Post: 25th Jun 2014, 12:44 PM
  4. Scrap steel - machining a drive shaft
    By nearnexus in forum METALWORK GENERAL
    Replies: 8
    Last Post: 2nd Jul 2013, 07:32 PM
  5. Scrap Steel/Copper prices
    By Pulse in forum METALWORK GENERAL
    Replies: 1
    Last Post: 16th May 2009, 07:31 PM

Posting Permissions

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