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  • Rake Crank Rod

    Hi all....I have several machines where the rake crank rod has worn a groove into the frame. The area worn is directly beneath the rod itself and the wear happens when the rod is as far down as it can go while 4:1 is moving. These worn places have been there since Ive worked there (2.5 yrs). However, one lane is shiny looking and Im finding small chips of metal around the area so this particular lane is in mid griding! Id like to find the cause/fix of/for this as the crank rod shows signs of being worn badly. The owner of the house thinks there is an adjustment, but cant remember where it is. Looking at the rake crank assm. it seems that possibly there might be an eccentric adjustment, but Im only guessing and I dont want to start extracting bolts until Im sure. Any thoughts?? I hope to tackle this in the morning.

    Thanks in advance....rob
    Space is the Place!

  • #2
    Re: Rake Crank Rod

    Rob:
    This happens when the rod is bent, with the bend curvature on the down side. Either replace the rod, or losen jam nuts and position the curvature to the top. As that will require approx. 1/2 turn of the rod, make certain you are lengthing it rather than shortening.(Important)
    Roscoe.
    rfm

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    • #3
      Re: Rake Crank Rod

      Roscoe......thanks. But the rods dont seem to be bent. I am in a 24 lane house and somewhere around 12 lanes are like this. Ive had bent rods before and have found that they effectively shorten the rods and cause problems with the rake hook either with regards to timing or in its ability to stay on the block....neither of which is happening to any of these approx. 12 lanes. This particular lane Im writing about now is grinding right now. The rod appears straight from any angle.

      Converted A2's with shotguns BTW.

      Any other ideas???
      Space is the Place!

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      • #4
        Re: Rake Crank Rod

        Planet:
        What are the serial #s of machines? The very earliest mchs., had a longer crank arm on them. However, like steel guide rollers, Otis sent out changeovers. Are all mchs. doing this, or just a few? Check the center to center measure, of the crank, on the ones doing it and compare to those not doing so. As far as an adj. to correct this problem , no there is not.
        Roscoe.
        rfm

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        • #5
          Re: Rake Crank Rod

          Oops......had to edit that last post. Not 18 lanes with this problem...12 (to answer your question and correct my above post). 12 lanes are like this.

          Serial # on this machine is 57,876. Something has had to change because I (hope) would have noticed the metal flecks and the "newness" of the groove the rod is making. Its eaten thru the frame to the hollow inside part of the frame.

          Ive seen bent rods before. Even minutely bent ones...and I attest that I believe these are straight.

          ...rob
          Space is the Place!

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          • #6
            Re: Rake Crank Rod

            Planet_rob
            I have 32 machines 27000 ser# in which all of them have eaten half through the shaft. Don't lose any sleep over it if your only now seeing hollow tube. I havn't had any problems related to this. I have however replaced all but 3 with collasible rake links. I noticed that even the slightest bend would hit the shaft. I've talked to many techs with lots of experience and they said not to worry unless you are 3/4 the way through.
            John B
            ------------
            just fix it

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            • #7
              Re: Rake Crank Rod

              My machines are of the same vintage as yours. I have several like you have with the holes. I have always found the problem to be a bent rod.

              The bushings could be worn at the top of the rake sweep arm (GB Pg.# 65 R161A) causing the rod to sit lower.

              Other than that I don't really know. [img]/content/btubb/images/%%GRAEMLIN_URL%%/confused.gif[/img]

              You could always convert them to the new A-2 style. They sit higher.
              <span style="font-style: italic">Sometimes it is best to use good advice from many individuals to achieve the ultimate result.</span>

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              • #8
                Re: Rake Crank Rod

                I would say you have a couple of options. You could do as BrunsAce mentioned...convert to A-2 style rods. They do sit higher and would eliminate the problem. I had this problem a few years back with a machine that had a serial number below 1000. (99? if I remember corectly) I removed the parallel links and drilled a 5/16" hole just above the 1/2" hole already there for the end of the crank link. This effectivley raised the crank rod above the cross member. It also made the adjustment very touchy for the crank link. It also got rid of the slop at the end of the rod making the adjustment a little tighter. It worked, but it wasn't pretty...

                I ended up replacing the rake arms on that machine and the problem went away completley. When I replaced the rake arms, I purchased two new parallel links to see if they might have been the original problem...they weren't. But after replacing the rake sweep assy. the problem dissapeared. The rake arms on that lane were the original version. I wish I had looked into the problem a little further before removing the assy. to see if the holes in the rake arm assy for the top of the parallel links were drilled in the proper place. As the assy sweeps rearward, the relative height of the holes changes as the rake arm pivots...raising the holes...if the plate that the holes are drilled in was welded on in the wrong position...couldn't that cause the rake crank rod to drag on the cross member? Just a thought.

                I went through the house welding a strap over the holes that had been worn into any of the cross members that had been caused by bent rods over the years. Some were only a small hole. Some were quite deep. I wouldn't wait until you are 3/4 through the cross member before solving the problem and repairing the shaft. A 1 inch wide by 1/8 inch thick strap of steel will cover the holes very well. Just cut them long enough to cover 1 inch past the end of the cut. I had a bonded welder come in and do the work just in case anything went wrong. He spent about 15 minutes per machine and I went in front of him removing the compression spring guide tube from the rake arm so he could have a clear shot at the material. Job went by fairly quickly, but we had 26 machines to do...so we took most of the day.

                Oh...your last option...bend the crank rod up so it won't touch the cross member. But I hate advising anybody to destroy a perfectly good part. Good luck...
                TSM & TSM Training Development
                Main Event Entertainment
                480-620-6758 for help or information

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                • #9
                  Re: Rake Crank Rod

                  Thank you all very much...my mind (and the house owners) will be a little more at ease with this.

                  ...rob
                  Space is the Place!

                  Comment

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