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Re: [z_scale] MT F units (was: MT vs. Mk F units...)

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  • Mr. W
    ... Thought that I d add a couple of cents worth here... In general, I have to agree with almost everything that s been said. The one thing that I haven t
    Message 1 of 7 , Dec 3, 2001
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      on Sun, 2 Dec 2001 09:44:55 EST, zbendtrack@... wrote:

      > If you take a MT apart, one strong suggestion: don't mix and match gears on
      > a loco that's been run. The gears take a "set" very quickly, and mixing them
      > up is not a good thing to do. Be certain the axles go back in the same truck
      > and in the same left/right orientation. You can fix one problem, and
      > potentially create another one in the process if you mix/match.
      >
      > Most common problems found?
      > 1. Dirty wheels (absolutely #1 problem)
      > 2. Poor connection between axles and truck frame (2nd most common)
      > 3. If the loco has ever been disassembled by the owner, problems with the
      > cat's whiskers and the truck
      > 4. If the truck has ever been disassembled by the owner, the challenge of
      > finding which axle goes in which truck, and left/right orientation (time
      > consuming to sort out)

      Thought that I'd add a couple of cents worth here...

      In general, I have to agree with almost everything that's been said. The
      one thing that I haven't seen in my diagnostic efforts on these little locos
      is that the placements of the wheels makes a difference. Now, there are
      wheelsets that are just not so good, but in general I've found that a good
      wheelset can go in left or right into any position on a truck.

      Something that I'd like to emphasize is that the gears should not be mixed
      up. These are assembled as a set in the factory, even before they are run
      in together. Mixing them up can cause many, many heart aches.

      Also, one of the most common whisker problems, and it has been known to
      happen with units that were assembled at the factory, not just the units
      that have been opened by customers, is that the whisker will actually work
      its way under the gear tower contact. This can cause the whisker to get
      somewhat bent out of shape and generally wreak havoc with the electrical
      conductivity. A normal symptom of this is if the truck will conduct power
      when it's turned one way but not the other and frequently not when it's just
      straight. (See Bill's Test Three.)

      As an interesting side light, I'm turning over an idea in my head about how
      to make a narrow body locomotive (i.e. GP7 or the like) using much of the
      MTL hardware as a starting point, but using a very different conduction
      path. Now, I must say this up front, I am looking at doing this for myself,
      and I am in no way interested in producing or selling these. MTL might get
      very mad at me if I tried such a thing, at least at this point. However, as
      time permits, I'll continue tinkering with this idea and I keep folks
      informed about my progress.

      -Geoff.
    • jmac_han@hotmail.com
      Hi Geoff, Bill, I have run into the bent whisker phenomenon on a couple of units. They will run well going aroung curves in one direction but not in the other.
      Message 2 of 7 , Dec 3, 2001
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        Hi Geoff, Bill,

        I have run into the bent whisker phenomenon on a couple of units.
        They will run well going aroung curves in one direction but not in
        the other. Obviously this is the symptom you refered to when turning
        the trucks one way or another. Ok Geoff, Bill, here's a question for
        you.

        Is there a way to improve the truck-to-sideframe conductivity? Any
        suggestions?

        I also concur with Bill K's diagnostic checklist. I have not had any
        problems with changing wheelsets around since I can never remember
        which way is up after I have taken them out of the trucks. When
        cleaning MT F7 wheels using an MTL speedidriver brass brush, I
        occasionally notice that the brass screws are conducting but that the
        wheels are not. This is a sure sign of poor electrical conductivity
        between the wheel collar and the truck sideframe. The solution I use
        is to remove the wheels and give them and the truck well a good
        cleaning with rubbing alcohol to remove the crud they have collected.

        Cheers,
        Jeffrey MacHan
        Chief Imagineer
        Val Ease Central Railroad



        > Thought that I'd add a couple of cents worth here...
        >
        > In general, I have to agree with almost everything that's been
        said. The
        > one thing that I haven't seen in my diagnostic efforts on these
        little locos
        > is that the placements of the wheels makes a difference. Now,
        there are
        > wheelsets that are just not so good, but in general I've found that
        a good
        > wheelset can go in left or right into any position on a truck.
        >
        > Something that I'd like to emphasize is that the gears should not
        be mixed
        > up. These are assembled as a set in the factory, even before they
        are run
        > in together. Mixing them up can cause many, many heart aches.
        >
        > Also, one of the most common whisker problems, and it has been
        known to
        > happen with units that were assembled at the factory, not just the
        units
        > that have been opened by customers, is that the whisker will
        actually work
        > its way under the gear tower contact. This can cause the whisker
        to get
        > somewhat bent out of shape and generally wreak havoc with the
        electrical
        > conductivity. A normal symptom of this is if the truck will
        conduct power
        > when it's turned one way but not the other and frequently not when
        it's just
        > straight. (See Bill's Test Three.)
        >
        > As an interesting side light, I'm turning over an idea in my head
        about how
        > to make a narrow body locomotive (i.e. GP7 or the like) using much
        of the
        > MTL hardware as a starting point, but using a very different
        conduction
        > path. Now, I must say this up front, I am looking at doing this
        for myself,
        > and I am in no way interested in producing or selling these. MTL
        might get
        > very mad at me if I tried such a thing, at least at this point.
        However, as
        > time permits, I'll continue tinkering with this idea and I keep
        folks
        > informed about my progress.
        >
        > -Geoff.
      • zbendtrack@aol.com
        ... locos ... Well, help me here. Always willing to learn, and thankful for the assist. I ve had four basket cases arrive over the last year for last rites
        Message 3 of 7 , Dec 3, 2001
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          Geoff:

          > one thing that I haven't seen in my diagnostic efforts on these little
          locos
          > is that the placements of the wheels makes a difference. Now, there are
          > wheelsets that are just not so good, but in general I've found that a good
          > wheelset can go in left or right into any position on a truck.

          Well, help me here. Always willing to learn, and thankful for the assist.

          I've had four basket cases arrive over the last year for "last rites" or
          "fixin." Two were "sorta" assembled and one was in a zip lock plastic bag
          upon arrival in the mail. Only one was in "as built" configuration, and it
          was just plain dirty and unlubricated.

          It could be I've just run into some of the "not so good" wheelsets you refer
          to. In any case, the performance of the three disassembled units upon
          cleaning and reassembly has worse than poor. One of them would run a few
          feet, and flat lock up the gear tower. One looked like a Mexican Jumping
          Bean, with the truck occasionally lifting the chassis up in the air while it
          bucked and pitched. The third one sounded like a meat grinder eating nails
          for lunch.

          In all three cases, by simply trying all possible combinations of axle
          location (4) and left/right (2), all three locos settled down and ran as
          smooth as glass.

          My experiences from the previous year of repairs for others was about the
          same. Once I saw the pattern, I locked on to it and work to maintain axle
          location/orientation to save grief.

          On the other hand, of the (6) that I personally own, I lost track one time on
          one loco on axle position, and, as you pointed out, it didn't make a
          difference.

          Was I just lucky on my own loco that one time? Or were the ones folks sent
          to me just unlucky ones? Is there something to look for? Anything come to
          mind that would cause this apparent "pattern"? You had the chance to see
          hundreds of them at the factory.

          > Something that I'd like to emphasize is that the gears should not be mixed
          > up. These are assembled as a set in the factory, even before they are run
          > in together. Mixing them up can cause many, many heart aches.

          Agreed.

          > As an interesting side light, I'm turning over an idea in my head about how
          > to make a narrow body locomotive (i.e., GP7 or the like) using much of the
          > MTL hardware as a starting point.

          I've been looking at BL2 plans so long my eyes are crossed. A natural for
          the power unit, with only minor filing required to the frame.

          Bill Kronenberger
          Houston
        • zbendtrack@aol.com
          ... Short of a soldered wire solution, none. I just clean both the wisker and the gear tower with Atlas Conductalube, make sure the wisker is straight and
          Message 4 of 7 , Dec 3, 2001
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            Jeffrey:

            > I have run into the bent whisker phenomenon on a couple of units.

            > Ok Geoff, Bill, here's a question for you.

            > Is there a way to improve the truck-to-sideframe conductivity? Any
            > suggestions?

            Short of a soldered wire solution, none.

            I just clean both the wisker and the gear tower with Atlas Conductalube, make
            sure the wisker is straight and positioned correctly, and reassemble the unit
            correctly.

            I don't perceive a bad design, just a rather typical scratch-and-pray one.
            One in which dirt and oil are free to get into.

            Regards,
            Bill Kronenberger
            Houston
          • Mr. W
            ... I d guess that you had a hand full of bad wheelsets come through. I think that the pattern might be that you were sent bad locomotives. A fair few of the
            Message 5 of 7 , Dec 4, 2001
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              on Mon, 3 Dec 2001 22:36:09 EST, zbendtrack@... wrote:

              > Geoff:
              >
              > Was I just lucky on my own loco that one time? Or were the ones folks sent
              > to me just unlucky ones? Is there something to look for? Anything come to
              > mind that would cause this apparent "pattern"? You had the chance to see
              > hundreds of them at the factory.

              I'd guess that you had a hand full of bad wheelsets come through. I think
              that the pattern might be that you were sent bad locomotives. A fair few of
              the locos that I worked on that had been sent in by customers for repairs
              had bad wheelsets. I didn't go to the trouble of trying to place them
              correctly, though, as I had the luxury of simply being able to go to the box
              on the shelf and grab a few new ones. It seems that every now and then a
              batch of bad wheelsets will slip through the cracks and make it out the
              door, and if you're in the position of trouble shooting locos, I'm sure that
              you'd see them.


              >> As an interesting side light, I'm turning over an idea in my head about how
              >> to make a narrow body locomotive (i.e., GP7 or the like) using much of the
              >> MTL hardware as a starting point.
              >
              > I've been looking at BL2 plans so long my eyes are crossed. A natural for
              > the power unit, with only minor filing required to the frame.
              >
              > Bill Kronenberger
              > Houston

              That could be an interesting one. What I'm really interested in, though, is
              getting a z-scale locomotive with a proper light-board, so that the DCC
              companies can make a plug and play z-scale DCC decoder. I played with some
              designs like that while at MTL, but don't hold your breath for such a thing.
              It was pretty low on the priority list, and as they only filled my position
              about a month ago, I doubt that my replacement's even looked at the z-scale
              projects yet.

              Geoff.
            • Mr. W
              ... Well, as a matter of fact, there is a method that I ve done a little bit of playing around with. I never got it past a first prototype, and unfortunately
              Message 6 of 7 , Dec 4, 2001
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                on Mon, 03 Dec 2001 17:01:53, jmac_han@... wrote:

                >
                > Ok Geoff, Bill, here's a question for you.
                >
                > Is there a way to improve the truck-to-sideframe conductivity? Any
                > suggestions?

                Well, as a matter of fact, there is a method that I've done a little bit of
                playing around with. I never got it past a first prototype, and
                unfortunately now I don't have the time or the tools to work on it, but this
                is a brief description:

                A properly shaped bit of brass can be inserted into the sides of the truck
                sideframe, with part contacting the surface of the wheels, and part sticking
                up and bent over at the center of the truck, on each side. Another piece of
                brass can be soldered to a spot on the gas tank of the side frame, such that
                when the trucks are assembled this new external whisker is contacting the
                bit that's sticking up from the truck.

                As I'm sure you can see, the common method used in N-scale locos is my
                inspiration. This is the method that I'll be incorporating into my scratch
                built GP-7, when I get around to working on it.

                At this point, I wouldn't recommend that anyone try to do this with one of
                their F-7s, though, unless you're willing to risk destroying it.

                -Geoff.
              • zbendtrack@aol.com
                ... Actually, that makes good sense. For those folks who have good wheelsets, they probably disassembled and reassembled their locos without any problem,
                Message 7 of 7 , Dec 4, 2001
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                  Geoff:

                  > I'd guess that you had a hand full of bad wheelsets come through. I think
                  > that the pattern might be that you were sent bad locomotives.

                  Actually, that makes good sense. For those folks who have "good" wheelsets,
                  they probably disassembled and reassembled their locos without any problem,
                  and I never hear from those folks at all.

                  But for those that have the other kind of axles, and get frustrated to the
                  point of quitting the hobby, I get to see them, packed in a zip-lock bag.
                  <grin>

                  Thanks. Now I know the "pattern" is not a pattern at all. Still, it takes
                  almost no effort to mark the wheels during disassembly, and potential trouble
                  is avoided no matter the situation at hand.

                  Regards,
                  Bill Kronenberger
                  Houston
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