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  • Pop quiz

    The Table moves faster when spotting pins.

    True or False?

    Explain your answer.

  • #2
    Re: Pop quiz

    False!

    50 Hz is 50 Hz
    60 Hz is 60 Hz
    If you have a good working motor!

    Try to explain that to the cops driving 100 mph uphill!

    Martin
    So it goes.

    Comment


    • #3
      Re: Pop quiz

      True

      Table moves farther distance in same amount of time.

      Comment


      • #4
        Re: Pop quiz

        Originally posted by dluke:
        True

        Table moves farther distance in same amount of time.
        <font size="2" face="Verdana, Helvetica, sans-serif">I think you are right afterall, I was thinking about the RPM of the motor.

        Martin
        So it goes.

        Comment


        • #5
          Re: Pop quiz

          True!

          Moves faster when spotting.

          Reason being the laws of physics and levers......the end of a lever....table drive actuated...allows more speed with the same power.

          Jerry

          Comment


          • #6
            Re: Pop quiz

            False:

            It moves at the same speed, since there is no "speed control" on the motor, and there isn't a multiple-speed "transmission" in the gearbox. The speed of the table drive is a "virtual constant". (there may be some deviation in speed due to gravity, weight of the table and pins, and which linkages are being moved when it is running)

            It does, however, take less TIME to spot then it does to respot, since a spotting cycle is only ONE rotation of the drive shaft, and a respot cycle is TWO rotations... but the actual speed of the driveline is the same.
            <span style="font-style: italic">Educatio est omnium efficacissima forma rebellionis</span>

            Comment


            • #7
              Re: Pop quiz

              The combo motor is 12:1 gear reduction and is the same RPM on all cycles.

              However, when the table drive is engaged the table has to cover more distance in the same rotation of the table shaft.

              In this case the speed of the table would have to be faster.
              Pinspotters do not break down when they are not running!

              Comment


              • #8
                Re: Pop quiz



                OK, my thought on this would be that it is faster since the eccentric is unlocked, which allows a gravity fall, rather than be lowered by a locked table drive during the respot cycle.
                "Where are we going, and why are we in a hand basket?"

                --Kat

                Comment


                • #9
                  Re: Pop quiz

                  true

                  the actual physical table (torque-tube &amp; aluminum deal) does move faster when spotting than when respotting

                  the motor of course is the same speed.

                  think about it, the motor runs the same speed, but when spotting it has more ground to cover in the same amount of time

                  Comment


                  • #10
                    Re: Pop quiz

                    well it seems like the table drive does the same job as a 2 to 1 on a brunslick [img]/content/btubb/images/%%GRAEMLIN_URL%%/laugh.gif[/img] .

                    one other thing when you run a 82/70 sweep in reverse all the way thru from zero to zero why does it not run the same speed! [img]/content/btubb/images/%%GRAEMLIN_URL%%/confused.gif[/img]

                    one more thing KAT stop beating your head against the wall!! you might damage something! [img]/content/btubb/images/%%GRAEMLIN_URL%%/laugh.gif[/img]
                    if things aren't going right just use a bigger hammer! DIRT

                    Comment


                    • #11
                      Re: Pop quiz

                      Ooh Jimmy Jam, leave it to you to think up arcane stumpers like this!

                      Though first impulse was to say "false," I thought about it.

                      Driveshaft runs at 12.1 (or 14.5). If it is forced to run faster or slower, motor will pop its klixon pretty quickly.

                      However, that is not the final drive speed of the table. Final drive speed is dependent on the table drive eccentric. it's either 12.1 X the distance between the center of the driveshaft and the center of the clevis rod end, or it's 12.1 X 1.
                      It depends on if the eccentric is engaged or not.

                      At the other end of the spotting solenoid train, the 6481 spotting arm and 1910 spot/respot cam also probably play a part in table speed at any particular moment during a cycle, but my brain is too worn out to fathom that right now.
                      That would depend on if the spotting latch is engaged or not.

                      Ugh that's enough. Time to watch some Beavis &amp; Butthead!

                      C [img]/content/btubb/images/%%GRAEMLIN_URL%%/smile.gif[/img]

                      Comment


                      • #12
                        Re: Pop quiz

                        Well said Chaddie.

                        Jerry

                        That is what college does for you!

                        Comment


                        • #13
                          Re: Pop quiz

                          TRUE!!!!

                          The table must move faster when spotting for one simple reason: The table drive yoke is farther from the center of table eccentric on a spotting cycle. If two people are running around a circular track, one on the inside lane and one on the outside lane, the person on the outside will have to run faster to stay on the same radius as the inside person. When the table drive eccentric unlatches, gravity and lever or wheel and axle action cause the table to move faster. It does not have true lever action however, since the eccentric is swiveling. Another way to think about it is, on a respot cycle, the table motor output makes one revolution to make the table go down pick up pins and come back to zero position. On a spot cycle, the table drive output makes one revolution, but this time the table has to go all the way down to the pindeck before returning to zero position. So it does have to go farther in the same amount of time. Therefore, faster. It might be hard to see that it takes the same amount of time to spot pins as it does for 1 motor revolution on a respot cycle. But the motor speed does not change. And both of the previous mentioned actions take place with exactly one revolution of the motor, therefore it takes the same amount of time.

                          Louie
                          Experience: Currently Help Maintain 44 82-30s and 50 82-70s.

                          Comment


                          • #14
                            Re: Pop quiz

                            Which figure does have a bigger surface;
                            a circle or an oval with the same outline?
                            So it goes.

                            Comment


                            • #15
                              Re: Pop quiz

                              Originally posted by Lampie:
                              Which figure does have a bigger surface;
                              a circle or an oval with the same outline?
                              <font size="2" face="Verdana, Helvetica, sans-serif">A circle has more area than an oval with the same diameter (at the widest spot).

                              Here's a little simple math to help the cause. I am not sure of the diameter of the table eccentric, so I am using 5 in. and 10 in. for an example.

                              For the 5 in.:

                              5(pi)=15.7 in. Circumference
                              14.5 RPM X 15.7 in.=227.65 in/min
                              227.65/60=3.79 in/sec
                              Therefore, the outer edge of the circle (or eccentric in this case) would travel at 3.79 inches per second.

                              For the 10 in.:

                              10(pi)=31.41 in. Circumference
                              14.5 RPM X 31.41 in.=455.445 in/min
                              455.445/60=7.59 in/sec

                              When the diameter increased, the speed of the outer edge of the circle increased to 7.59 inches per second. In this case, the outer edge speed is directly proportional to the diameter.

                              Louie [img]/content/btubb/images/%%GRAEMLIN_URL%%/wink.gif[/img]
                              Experience: Currently Help Maintain 44 82-30s and 50 82-70s.

                              Comment

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