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Re: [mill_drill] Re: new article available: An Experimental Way toStat ically Balance a Bench Grinder

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  • Bill Stietenroth
    The biggest problem I have with new bench grinder wheels is the crappy little plastic center bushing that those cheapskates provide with the wheels. I have
    Message 1 of 4 , Jul 31, 2011
      The biggest problem I have with new bench grinder wheels is the crappy little plastic center bushing that those cheapskates provide with the wheels. I have made some aluminum bushings that I use instead which eliminates most of the problems before I even start mounting a new wheel. After mounting it and running it for a minute, I true it up with an abrasive stick and diamond. If it still vibrates, I change wheels and take that one back to the vendor. Bad wheel. I get very few, most will true up very well.
      On this subject, does anyone know why the shoulder for the inside washer on most grinder shafts is so small? I made a special tight fitting inside washer for mine to keep it from trying to over run the shoulder.
       
      Bill in Houston

      ---------- Original Message ----------
      From: Rick  Sparber <rgsparber@...>
      To: "mill_drill@yahoogroups.com" <mill_drill@yahoogroups.com>
      Subject: Re: [mill_drill] Re: new article available: An Experimental Way toStatically Balance a Bench Grinder
      Date: Sun, 31 Jul 2011 08:12:00 -0600

      Denis,
      Yup, that was where I started. To me, their product is a proof of concept. There is no way I would pay that kind of money for something that is easy to make.
      In the end I came to realize that I did not need to add an external weight in order to balance my grinder. The problem was in a defective wheel. It must have a non-uniform distribution of grains in the wheel. It looks OK but when mounted and trued, still causes a lot of vibration. Its replacement runs much smoother. I did try to improve the balance of the new wheel but could not by simply adding a weight. My guess is that the static balance is good but the dynamic balance is a little off. In order to correct for dynamic balance, I need to be able to place a weight at a given distance from the center of rotation at a given angle plus a given point along the center of rotation. Not so easy to do on a grinder.
      So in the end I pulled the article you read from my site and left a more traditional one.

      Rick

      On Jul 31, 2011, at 7:55 AM, "zapvss" <zapvss@...> wrote:


      Hello Rick,
      Here is  link you may be interested in for a gadget used to balance grinding wheels.

      http://oneway.ca/index.php?page=shop.browse&category_id=42&option=com_virtuemart&Itemid=2

      Denis

       

      --- In mill_drill@yahoogroups.com, "RG Sparber" <rgsparber@...> wrote:
      >
      > This article presents a way to statically balance a bench grinder using a
      > piece of steel strap and a marker pen. I was able to greatly reduce
      > vibration in my grinder but until other are able to reproduce this work, I
      > am reluctant to say it really works.
      >
      >
      >
      > If you are interested, please see
      >
      >
      >
      > http://rick.sparber.org/gsb.pdf
      >
      >
      >
      > Your comments and questions are always welcome. All of us are smarter than
      > any one of us.
      >
      >
      >
      > Rick
      >

       

    • Rick
      Bill, My guess is they save significant money on the smaller diameter shaft and a few pennies on the junk washers. As for those plastic inserts, they are the
      Message 2 of 4 , Jul 31, 2011
        Bill,

        My guess is they save significant money on the smaller diameter shaft and a few pennies on the junk washers.

        As for those plastic inserts, they are the first to go. 

        Rick

        On Jul 31, 2011, at 3:50 PM, "Bill Stietenroth" <k5zty@...> wrote:

        The biggest problem I have with new bench grinder wheels is the crappy little plastic center bushing that those cheapskates provide with the wheels. I have made some aluminum bushings that I use instead which eliminates most of the problems before I even start mounting a new wheel. After mounting it and running it for a minute, I true it up with an abrasive stick and diamond. If it still vibrates, I change wheels and take that one back to the vendor. Bad wheel. I get very few, most will true up very well.
        On this subject, does anyone know why the shoulder for the inside washer on most grinder shafts is so small? I made a special tight fitting inside washer for mine to keep it from trying to over run the shoulder.
         
        Bill in Houston

        ---------- Original Message ----------
        From: Rick  Sparber <rgsparber@...>
        To: "mill_drill@yahoogroups.com" <mill_drill@yahoogroups.com>
        Subject: Re: [mill_d rill] Re: new article available: An Experimental Way toStatically Balance a Bench Grinder
        Date: Sun, 31 Jul 2011 08:12:00 -0600

        Denis,
        Yup, that was where I started. To me, their product is a proof of concept. There is no way I would pay that kind of money for something that is easy to make.
        In the end I came to realize that I did not need to add an external weight in order to balance my grinder. The problem was in a defective wheel. It must have a non-uniform distribution of grains in the wheel. It looks OK but when mounted and trued, still causes a lot of vibration. Its replacement runs much smoother. I did try to improve the balance of the new wheel but could not by simply adding a weight. My guess is that the static balance is good but the dynamic balance is a little off. In order to correct for dynamic balance, I need to be able to place a weight at a given distance from the center of rotation at a given angle plus a given point along the center of rotation. Not so easy to do on a grinder.
        So in the end I pulled the article you read from my site and left a more traditional one.

        Rick

        On Jul 31, 2011, at 7:55 AM, "zapvss" <zapvss@...> wrote:


        Hello Rick,
        Here is  link you may be interested in for a gadget used to balance grinding wheels.

        http://oneway.ca/index.php?page=shop.browse&category_id=42&option=com_virtuemart&Itemid=2

        Denis

         

        --- In mill_drill@yahoogroups.com, " RG Sparber" <rgsparber@...> wrote:
        >
        > This article presents a way to statically balance a bench grinder using a
        > piece of steel strap and a marker pen. I was able to greatly reduce
        > vibration in my grinder but until other are able to reproduce this work, I
        > am reluctant to say it really works.
        >
        >
        >
        > If you are interested, please see
        >
        >
        >
        > http://rick.sparber.org/gsb.pdf
        >
        >
        >
        > Your comments and questions are always welcome. All of us are smarter than
        > any one of us.
        >
        >
        >
        > Rick
        >

         

      • Bill Stietenroth
        I m not going to stand in front of an 8 grinding wheel turning 3600 rpm if it doesn t balance after putting a true bushing in the center hole and trueing the
        Message 3 of 4 , Jul 31, 2011
          I'm not going to stand in front of an 8" grinding wheel turning 3600 rpm if it doesn't balance after putting a true bushing in the center hole and trueing the OD. If it still vibrates after that, it is defective and defective wheels turning 3600 rpm are subject to come apart, balancing weights or not. If I pick up my hand grinder and it stings my hand with vibration when I start it, I change wheels. No balancing. When a grinding wheel comes apart, it does damage. Supply companys take defective wheels back, why fool with them?
           
          Bill

          -------- Original Message ----------
          From: Jerry Durand <jdurand@...>
          To: mill_drill@yahoogroups.com
          Subject: Re: [mill_drill] Re: new article available: An Experimental Way toStatically Balance a Bench Grinder
          Date: Sun, 31 Jul 2011 17:51:27 -0700

          Same here but there seems to be a lot of people who wind up with unbalanced wheels (otherwise various people wouldn't sell wheel balancers).

          On 07/31/2011 05:03 PM, Rick wrote:
          My experience was that non-defective wheels don't need the extra balancing weights. 

          Rick

           
          -- 
          Jerry Durand, Durand Interstellar, Inc.  www.interstellar.com
          tel: +1 408 356-3886, USA toll free: 1 866 356-3886
          Skype:  jerrydurand
        • Rick
          Bill, Someone new to our hobby might be confused by your statement. If the grinder is dancing around the bench it is due to vibration and is certainly a
          Message 4 of 4 , Aug 1, 2011
            Bill,

            Someone new to our hobby might be confused by your statement. If the grinder is dancing around the bench it is due to vibration and is certainly a danger sign. But I'd you place your hand on the motor housing and can feel the difference between on and off, that is vibration too. That is why I made the YouTube video. Words alone don't convey how much vibration is ok.

            Rick
            rick.sparber.org

            On Aug 1, 2011, at 1:47 AM, "Bill Stietenroth" <k5zty@...> wrote:

            >
            >
            > I'm not going to stand in front of an 8" grinding wheel turning 3600 rpm if it doesn't balance after putting a true bushing in the center hole and trueing the OD. If it still vibrates after that, it is defective and defective wheels turning 3600 rpm are subject to come apart, balancing weights or not. If I pick up my hand grinder and it stings my hand with vibration when I start it, I change wheels. No balancing. When a grinding wheel comes apart, it does damage. Supply companys take defective wheels back, why fool with them?
            >
            > Bill
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