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Balancing Flywheels?

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  • Balancing Flywheels?

    Is it possible to balance a lathe lightened flywheel in a manner similiar to balancing a grinding wheel? Like a tight fitting arbour perhaps machined threaded with two cones mounted one on each side of the shaft that could sandwich a flywheel between the two tapers accurately? HMNM Thanx Mike

  • #2
    I see no problem, should work on any rotating piece, whether a grinding wheel or a flywheel as long as it is centered.JIM


    • #3
      While at first glance it seems pretty obvious, I might have a look to see what's up with dynamic vs. static balancing. The couple reciprocating assemblies I had done over the years were dynamically balanced by House of Balance in Baltimore.

      They match all the components, calculate a bob-weight, and go from there. All these engines were eerily smooth, and in the case of a really crappy looking FZ600 racebike, it added significant power, and no one ever would have suspected amount of blueprinting, balancing, and head development that went into such a truly sorry looking bike. Good balancing is worth the time or expense.
      "Lay on ground-light fuse-get away"


      • #4
        If you are talking about automotive flywheels not all are balanced equally. The 289/302/351 Fords had an off balance flywheel and front balancer. They were either 28 oz or 50 oz out of balance depending on the year. Im not sure how many others were like that. Wow, 50 oz, isnt that about 3lbs wizzing around at up to 6000 rpm. I wonder what the internal forces are.



        • #5
          An acquaintance ran a hi perf engine shop and grocery getters if times were slow, he showed me one of his pride and joy machines his crankshaft balancer, basically a small lathe with an Oring to drive the crank and the speed was absurdly slow 70 rpm or something, it would run then stop and tell you where and how much to drill to remove weight or add mallory, he claimed it was 9000rpm Nascar technology????

          MM I know your into Japanese bikes but I recall harleys being always balanced at a percentage, must have been for their close firing order or long stroke combos??????
          Opportunity knocks once, temptation leans on the doorbell.....


          • #6
            Mike, if you got your hands on Harley flywheels I can send you a relative pdf..
            Excuse me, I farted.


            • #7
              "...3lbs wizzing around at up to 6000 rpm. I wonder what the internal forces are."

              Probably not much different than if it were balanced. However, the crankshaft is really taking it on the flange.

              Any products mentioned in my posts have been endorsed by their manufacturer.


              • #8
                I once found some accelerometers used in dynamic balancers. Pretty neat. Really expensive. Sold them on ebay...

                I have a another accelerometer at home and a amp to go with it. pretty darn sensitive. I set the sensor on the pool table and dropped a ball from couple inches from the carpet next to the table and it showed up clearly on the scope. Even just slowly waving it in the air will cause noticeable deflection. I am thinking of attaching the sensor to the headstock of my lathe to check out the bearings.


                • #9
                  madman, a shop I worked at used static balancers that had A frames on each end with two dry ball bearing sharp edge rollers at the top of each A frame. The part to be balanced was mounted on a shaft and laid in the rollers and rotated and allowed to stop. The bottom was the heavy spot and continued drilling and rotating would ballance it staticly and that is a rough balance but to be exact it needs dynamic balancing.
                  It's only ink and paper


                  • #10
                    Rough Balance

                    Wouldnt machining the fly wheel in machined soft jaws for accuracy and then removing a exact amount almost guarantee No need for balancing? I once Hacksawed a few crank counterweights of a 750 Honda four that ran a big bore (made from suzuki engine parts pistons liners Yamaha con rods and it ran on alcohol) kit home brew and after hacksawing and smoothing it out never balancing it whatsoever it actually ran mighty smooth? Explain this if you can guiys?? thanx Mike the Mad Balancer