Kato Double crossover Stutters ONLY on one Route or Path

Mark Ricci Apr 24, 2021

  1. brokemoto

    brokemoto TrainBoard Member

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    Take the back plate off of the unit. Make sure that all of the metal plates are contacting properly. I have had several Kato turnouts show continuity problems because some of the internal parts are not making proper electrical contact.
     
  2. Mark Ricci

    Mark Ricci TrainBoard Member

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    Thank you Rick. Yeah, I knew flipping d crossover shouldn't make a difference but by that time, started fishing. Typically ohm out all feeders from top of joiner to pin inside mini tamaya, before installation but will check again. No insulating joiners are installed anywhere on the track.
     
  3. RBrodzinsky

    RBrodzinsky Staff Member TrainBoard Supporter

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    Make sure none of the rails are "riding up" over the unijoiner. This can happen, and then you get intermittent contact. Hence my comment to make sure that each RAIL has continuity to its adjoining rail, through the unijoiner. Also, make sure the unijoiners are flush into the plastic (use a small flat blade scewdriver to push them down). If you hadn't swapped the x-over, I would have also suggested that one of the switches within the x-over was not conducting well, but I can't believe it would be the issue on two.

    Trucks "hopping" -- THIS IS BAD. Make sure all points are flush to the proper closure rail. How are you controlling the x-over (manually throwing the four sliders, or electrically)? Without locos on the track, do all 4 switches move in unison and sit properly. For each position on each of the 4 switches, is the frog powered? Are the point rails powered (with correct polarity)?
     
  4. Mark Ricci

    Mark Ricci TrainBoard Member

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    Will check joiners and perform if necessary. Thank you.

    Was using Kato DC throttle with Kato turnout control switches but always falling off or worse, partial connection and not totally throwing the crossover or turnout. how amazing the engineering inside the d crossover its hard to believe that Kato uses connection designed for electrical also as a means to physically attach turnout switches to the throttle. At any rate, with the 3 key turnouts, double x over, the RT and the wye, sequenced via truth table approach all 8 combinations and no short occurs. Early last week started using all turnouts manually. The wye does not have powered frog. All feeder whites are on outer rail all blue feeders on inner rail. Hoping also occurred on new d crossover.
     
  5. sidney

    sidney TrainBoard Member

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    i had a contact from in side one of my cross overs not soldered IE it became unsodered . i had to resolder those that touched the rails est. very hard to see them. i found them by using a very small needle and looking through the small holes top side poked them and found a few that came loose. might check that. i dont have pics.
     
  6. Mark St Clair

    Mark St Clair TrainBoard Member

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    Did you try the shims on the track pieces on each end of the xover or just under the xover itself? I had a problem with a similar layout configuration as yours. The issue turned out to be the curved track leading into the xover. While the xover was level, the curve was off-camber (opposite of super elevation). It was so subtle I could not see it. Caused the locos to rock ever so slightly away from the inside of the xover. The solution was to shim the curve leading into the xover, raising the outside rail of the curve. Do you have any steam engines with 2 wheel pilot trucks? Those were particularly sensitive and led me to the solution.
     
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  7. mtntrainman

    mtntrainman TrainBoard Supporter

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    Just out of curiousity...can you set that #4 turnout back to power routing? Curious if that turnout may be at faullt. Process of elimination. Worth a shot...JMO.
     
    Last edited: Apr 25, 2021
  8. ggnlars

    ggnlars TrainBoard Member

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    The route your having problems with has more voltage loss than the other one. Your seeing the stutter at low throttle setting. That means it is in the PWM region on both the Decoder & the DC supplies. The max voltage is lower on this path. Since it happened with two different cross overs, the loss occurs before the crossovers. Mark on your picture where your power feeders are. Track joiners are terrible for this problem. This is the reason on regular track you solder the feeders to every section. If you could measure the voltage at various places it would help, but at the low throttle region it is hard to do. The symptom is probably there at high throttle, but there it shows up in a reduced speed.
     
  9. mtntrainman

    mtntrainman TrainBoard Supporter

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  10. Mark Ricci

    Mark Ricci TrainBoard Member

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    Thank you for the reply. Lower right leg shim - Mostly under rerailer and partially under s62. Upper Left Shim - 95% under 9" radius, very small % under leg. Going to remove all shims and insert just one under outside rail of 9 radius entering upper left of d x-over. The smallest loco is an analog Bachmann Plymouth switcher which interestingly is partially how this was issue was discovered and initially thought stutter issue was related to loco. Also, bought it used so unsure of its condition.
     
  11. Mark Ricci

    Mark Ricci TrainBoard Member

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    Yes, used that document to configure all turnouts. Swapped out #4 RT with straight track early last week. Same issue
     
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  12. Mark Ricci

    Mark Ricci TrainBoard Member

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    Thank you for the reply. A diagram illustrating all power feeds posted yesterday (untitled). Feeders directly connected to d xover legs. Even replaced F62 connected to lower right leg with feeder to eliminate the F62's small connector and length. Can use DMM to measure but question accuracy since PWM is bipolar DC and not an ac RMS value at 60hz, which is what the DMM voltage function is designed to measure though can be used as a rough reference. Definitely agree about soldering, did that with my last layout and been thinking about it however that was bigger Atlas HO scale without plastic roadbed so really prefer to avoid if at all possible.
     
  13. Mark Ricci

    Mark Ricci TrainBoard Member

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    Unsure if this would help but made short video's with both loco's passing thru good and bad routes. They range from a few hundred k (the bad path videos) to 1.5M (the good path videos) in size. Since I'm new here, do not want to upload without knowing if ok.
     
  14. Mark Ricci

    Mark Ricci TrainBoard Member

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    Thank you for the reply. Had opened up the d xover and cleaned with CRC. Didn't notice anything disconnected. Attached is a picture of it. Maybe you can see something missed however bear in mind that a new crossover was inserted in layout, tested and failed exactly the same way so the original crossover is back in the layout.
     

    Attached Files:

  15. mtntrainman

    mtntrainman TrainBoard Supporter

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    Well...this one is a head scratcher for sure....:confused:
     
  16. Hardcoaler

    Hardcoaler TrainBoard Member

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    Wow mtntrainman, that's a great link. Thanks for posting it. (y)
     
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  17. tonkphilip

    tonkphilip TrainBoard Member

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  18. tonkphilip

    tonkphilip TrainBoard Member

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    Mark, You have probably checked these two items but just in case: 1. When adding DCC, sometimes the trucks do not sit quite right afterwards because the contact strips are twisted or out of place; 2. The #4 Unitrack turnouts are notorious for switch rails not fitting well, so is their potentially a mechanical problem where the locomotive wheels are being squeezed as they go through the turnout, causing rough operation, (see Unitrak tips). This is potentially accentuated by any curved rails attached directly to the turnout causing an S-bend through the turnout. - Tonkphilip
     
  19. Doug Gosha

    Doug Gosha TrainBoard Member

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    Hey, what's with all this "Kato #4 switches are notorious..." business? I thought Kato Unitrack is "bulletproof".

    :D

    Doug
     
  20. tonkphilip

    tonkphilip TrainBoard Member

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    Mark, A third item to check particularly if one locomotive is at fault: 3. Check the back-to-back spacing of each wheel set. You can check this with an NMRA track gauge, a Microtrains coupler gauge or a caliper. - Tonkphilip
     
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