2x72" Belt Grinder as a Foundry-Related (Pattern-making) Tool

Discussion in 'Foundry tools and flasks' started by Melterskelter, Oct 4, 2021.

  1. Melterskelter

    Melterskelter Gold Banner Member

    Today I did a bit of a vibration test demo:



    The grinder is turning at just under 6000 feet per minute.

    Denis
     
  2. Zapins

    Zapins Gold Banner Member

    Man these grinders are super tempting to build. I'd love to have one. There is a plasma cutter shop nearby about 2 hr drive away I could probably have the patterns cut out if I had the 3d model plan. But the wheels are the part I don't want to spend a huge amount of cash on. I wonder if I could make my own on the lathe that would be any good?
     
    DavidF likes this.
  3. Melterskelter

    Melterskelter Gold Banner Member

    The guy who made the plans will supply CAD files for just that purpose. Thet is how our group had them laser cut. Plasma would be OK but realize plasma cut surfaces are darned hard---nitrided due to heat and atmosphere. Water jet would be better. He suplies paper templates in his plans download.

    The planms are dirt cheap for what you get. 30 bucks.
    https://www.etsy.com/shop/Jerswoodshop

    Note: he sells metric and Imperial plans. They are each optimized for raw stock that is metric or imperial. Buy metric if you will use metric stock and Imperial if you will buy Imperial stock.

    You save a lot of time getting parts CNC cut. I have some thoughts about where to deviate from the plans too as I think there are some ways (that I implemented) that work better than a few things he suggested.

    Denis
     
    Last edited: Nov 25, 2021
  4. Zapins

    Zapins Gold Banner Member

    What about motor size? I'm guessing a faster >3,000 rpm motor in the 2 to 4 hp range would be best? I'd love to take some super aggressive cuts through metal. I've seen some bigger sanders made using go-cart wheels that really eat metal for breakfast.
     
  5. Melterskelter

    Melterskelter Gold Banner Member

    2 HP 3-phase 3750 that I will be over-driving to 4500 or so. It's induction so no moving coils. Will provide 6000 SFM on the belt.

    Denis
     
  6. Zapins

    Zapins Gold Banner Member

    Gotcha. I have a 1 or 1.5 hp 3750 motor in the shop that I salvaged. Might work always nice to have more power though.
     
  7. Melterskelter

    Melterskelter Gold Banner Member

    With respect to the motor you have, it may be adequate at 1.5 horses. But, if you use it, buy a VFD for a two, just in case. The cost difference is small. That way you can upgrade painlessly if needed now or the salvaged motor fails at some point.

    Denis
     
  8. Melterskelter

    Melterskelter Gold Banner Member

    I have mentioned the fibrous nature of the swarf produced by the belt grinder in a couple places. Well, today I decided to get out a ten power magnifier and exam a somewhat cohesive mat not pile of swarf I made doing some grinding yesterday. I have no special macro photo gear so I just let my iPhone look through the magnifier. A rather marginal work-around but one that still produced a couple images that makes the point of how different the swarf produced by the belt grinder is compared to the granular stuff that comes off a snag wheel. The belt used was a Norton Blaze 60 grit.

    Here is an image of a mat of fibrous swarf suspended in mid air and holding together.
    8BA878C8-9113-4523-80CB-74C54FA8CAA2.jpeg

    And here is a magnified view of the swarf showing its fibrous nature. Magnifying the material first hand I can actually see little balls of steel on the ends of the fibers where the molten metal coalesced on the end of the fiber. Interesting.
    734D8FD0-C0A7-4D21-9B06-6289776323D6.jpeg 1DF59A5F-EE48-41F5-ADD8-B328AA08AE58.jpeg



    I found this material to be fascinating and quite unexpected. Probably very old hat for long-time BG users.

    Denis
     
    Last edited: Dec 15, 2021
  9. I've seen the same from a surface grinder with a very coarse wheel on mild steel and thought about how steel wool get made.
     

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