MTL couplers and the "inchworm" (slinky) effect

Mark Truelove Jul 15, 2021

  1. CSX Robert

    CSX Robert TrainBoard Member

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    No the one adding friction to his cars is limiting himself, either on the number of cars he can pull or which cars can be on the end of the train.

    I'm not obsessed with it, but I would like to find a solution. I am glad Micro-Trains found a solution to the big ugly Rapido. I'm also glad someone found the solution to running multiple trains on the same track without having to throw a bunch of toggles. I'm also glad people have found better drive trains for our locos than what we had 40 years ago. If everyone was satisfied with the status quo and never tried to find solutions to problems they see, the hobby would never have progressed to the wonderful state it is in now.

    I have seriously considered switching out my Micro-Trains couplers for Accumates, but currently you can't even buy them separately right now, you can only purchase them with the trucks, and I'm not going to go to that expense (an extra couple of dollars per car I was ok with, but not $4-$5 a car).

    Actually, Accumates are almost the exact same size as Micro-Trains and McHenry's are just a hair longer. If you buy trucks with them they stick out a lot further because they are mounted further out on the truck. An Accumate mounted in a Micro-Trains coupler pocket gives the same coupling distance, has no slinky action, and in my experience works almost if not just as well as Micro-Trains(and in my opinion actually looks a little better). This is the route I would have gone when I was considering converting to Accumates.
     
  2. mtntrainman

    mtntrainman TrainBoard Supporter

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  3. Randy Stahl

    Randy Stahl TrainBoard Supporter

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    My solution to unit trains was to convert all the cars to MT Tru Scale couplers. IMG_0199.jpg
    These car types rarely ran in general freight so no slinky here, imagine 120 of these little cars bouncing back and forth.
     
  4. Inkaneer

    Inkaneer TrainBoard Member

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    Really? I run 2 (AA) and four unit lash ups (ABBA) of hood units and at least 2 road units all the time. Every once in a while the lead locomotive on a two locomotive lash up will disengage. The other locomotive has no trouble pulling the train which can number 24 cars. This happened just this weekend at a train show . Had a 24 car plus caboose train pulled by two Atlas SD35's. The lead SD35 broke away and the other SD35 had no problems pulling the train. That does not happen on my ABBA and AA lash ups as I use Unimates on the B units and the rear of the A units to ensure they couple really close and never had a break away. So I see no limitations here.

    Well when you find a solution then you tell us about it but this topic is not new and has been covered on this forum as well as The Railwire, N Scale Net, the old Atlas forum and possibly the Bachmann forum for almost two decades now and MT couplers are still the N scale favorite. But MRR Rule #1 still applies.

    Well then, I offered you a low cost method of dealing with the problem and you rejected it. By the way, replacing the spring with foam or some form of rubber or other such material is not new either. That was discussed on another forum and, long story short, it is no panacea. Can't recall what the major disadvantage was but I'm thinking it had to do with the uncoupling action. I could be wrong on that and maybe someone with a better memory could elaborate.

    And what are the downsides of the McHenry and the Accumate couplers??? There is a reason why MT couplers are the couplers most N scalers use. "...you ever think of that? [Sgt Stanislaus 'Animal' Kuzawa as played by Robert Strauss in 'Stalag 17']
     
  5. acptulsa

    acptulsa TrainBoard Member

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    If you do it wrong you could definitely make uncoupling difficult.

    If you don't mind me asking, what else is wrong with Accumates besides the car spacing?
     
  6. CSX Robert

    CSX Robert TrainBoard Member

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    I wasn't intending to mock, I was just trying to point out that we all have things we care about and other things that we really don't care too much about. If none of us really cared about the many aspects of modeling, then the hobby wouldn't be anywhere near where it is today.

    I also didn't intend for my list to be silly examples that people obsess over, just things that some people care about and others don't. For example, if someone pays over $200 for a sound equipped engine, I can understand if he wants it to have the correct sound, but I wouldn't even know if it did and would be happy as long as it sounds like a train engine.
     
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  7. CSX Robert

    CSX Robert TrainBoard Member

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    Ok, so in your situation you are not limiting yourself, but it still stands to reason someone adding resistance to their cars is more likely limiting himself than someone who is not.

    But you don't seem to think it applies to other model railroads? The best solution for you and your railroad is not necessarily going to be the best solution for someone else's.

    You offered a solution that does work. Many people use that solution, it's appropriate for their situation and they are quite happy with it. I rejected it because in my situation it would limit what I could run (and then you said I was limiting myself for rejecting it?)
     
  8. CSX Robert

    CSX Robert TrainBoard Member

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    I know of three major complaints people have with Accumates.

    1. As mentioned, car spacing. Accumate trucks with couplers have the coupler mounted further out(apparently for some reason to maintain truck compatibility with rapidos) resulting in much further car spacing. The actual coupler, however, is about the same length as a regular Micro-Trains and if you put it on a Micro-Trains truck or use a body mount they come out the same. Here's a picture of the the couplers to compare:
    [​IMG]
    2. Coupler boxes coming apart. The Accumate truck coupler box design is not as secure as the Micro-Trains one, and is known to come apart (google "exploding Accumates"). The body mounts don't if you screw them to the car or if you put them in Micro-Trains trucks you get the advantage of the better designed Micro-Trains box that do not come apart.

    3. Trip pins falling out. The Accumates are known to have trip pins that are not as secure and can fall out(although I've never had it happen). Some people who don't use magnetic uncoupling just remove them, but you can also add a drop of glue.

    4. (Yeah, I know I had 3, but this isn't a design issue) You currently cannot buy them without purchasing them with trucks.
     
  9. JMaurer1

    JMaurer1 TrainBoard Member

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    Can we go back to trying to come up with a solution instead of debating if this is something that bothers you or should bother you or doesn't bother you and why doesn't it bother you? The foam thing is a possible solution but the possible disintegration of the foam is a real thing (I came from HO in the '80's and had lots of brass locomotives with dust for foam).
     
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  10. acptulsa

    acptulsa TrainBoard Member

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    Thank you. Looks like your notion solves two out of four.

    Eventually, yes.
     
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  11. JMaurer1

    JMaurer1 TrainBoard Member

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    I posted just as CSX Robert posted...

    From that picture, the Kato couplers win! I might have to take a better look at them...more scale appearance and only about $1 a car.

    By the way, I somehow expected more from a search of "exploding accumate"...something more like:

    [​IMG]
     
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  12. CSX Robert

    CSX Robert TrainBoard Member

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    The Katos are a bit of an oddball. I really like their design, they use a spring for centering and closing, similar to how Micro-Trains does but the coupler is mounted on a post that it can not slide back and forth on (the Micro-Trains coupler being able to slide back forth on the post is what allows for the slinky action). The problem with them is they cannot easily be used in a Micro-Trains style coupler pocket and they are not easy to body mount(except on cars and engines designed to accept them).
     
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  13. Doug Gosha

    Doug Gosha TrainBoard Member

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    You mean they deleted that? That IS what happens. You must be certified in burn trauma and treatment to use them.

    :D

    Doug
     
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  14. Inkaneer

    Inkaneer TrainBoard Member

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    1. They are not reliable on trains over 25 or so cars. They tend to have frequent false uncouplings.

    2. They lose their trip pins.

    3. The coupler boxes were known to 'explopde'. Actually come apart spewing parts.
     
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  15. Inkaneer

    Inkaneer TrainBoard Member

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    [QUOTE="CSX Robert, post: 1188717, member: 7105"] Ok, so in your situation you are not limiting yourself, but it still stands to reason someone adding resistance to their cars is more likely limiting himself than someone who is not.[/QUOTE]

    You missed the point. I run with two units because that's what I want to do and not what I have to do.
    So where is the limitation?

    Don't try to put words in my mouth that I did not say. MRR#1 is universally applicable ​

    No. I said I offered you a low cost solution to the problem. You rejected the high cost option of replacing all the MT's with Accumates, as too expensive. So if you don't like the solution that I offered then find one that suits you and quit arguing with people who offer to help. Now I am done with this issue.​
     
  16. Mark Truelove

    Mark Truelove TrainBoard Member

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    Hey I'm just re-reading this old thread as I'm rebuilding Inglenook v2. Since you wrote this right after my earlier update, and have all the info, I can only guess that what you're not seeing is the critical behavior of unwanted magnetic uncoupling when the slinky effect is present. Since this is a fully hands-off implementation, I needed to fix this, whereas someone running a long train and not performing hands-off operations might only notice slinkying as a slight visual disturbance.

    On my v2 I'm utilizing custom under-track magnets that I came to prefer after trying about 35 different combinations of in-track, above-track and below-track neodymium combos, and I'm trying some manufactured wiper kits instead of the applied velcro pads this time to provide the needed rolling resistance to make it all work.

    I'm also shortening the legs and using only 40' boxcars to see how compact I can get it this time.

    Otherwise I'm amazed at the amount of discussion that came out of all this! I only wish I'd realized it was known as slinkying before I made that first inchworm post.
     
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  17. BarstowRick

    BarstowRick TrainBoard Supporter

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    Oh gosh here we go again. First off thanks for your response to my input. About two cents worth on my part.

    MTL's are my first choice and will remain so. There's one other brand out there but it's still in trial stages of exasperation.

    I'm fully aware of what many call the slinky effect. I've seen it on my downhill freights where the caboose can really be called a bob-er. Slam bang, whip-lash, worse then a roller coaster ride. I call it radical "Slack" over exaggerated for sure. Yes, I see it. Darn it!!

    One of the features and I think I've said this somewhere else. "We don't have the ability to adjust the brakes". As a result we aren't able to control the slack in a train.

    You can try all those things you mentioned to reduce the slinky effect. I wish you the best with that. I won't alter a MTL N scale coupler. You really don't want to see the results.

    I go looking for old Atlas or Model Power caboose trucks that have a considerable amount of drag. Then the slinky action only goes one way. Say what?? The train will drag the caboose down the hill while it stretches-out some of the couplers (reducing the slack). You know at the end of the train. Watch what happens when you stop suddenly. Not recommended when you are drifting downgrade. I think most of you already understand the possibilities or subsequent consequences. Cause and effect.

    Most toy train operators aren't bothered by the slinky effect. They don't have to care about it. On my railroad and those of my friends we all growl a little when we see something that isn't prototypical. Now that's a Model Railroader.

    Again, best wishes. You hang in there.
     
    Last edited: Apr 18, 2023
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  18. BigJake

    BigJake TrainBoard Member

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    An elder co-worker of mine talked about his experiences as a college summer-hire at ATSF in the panhandle of TX (his father's employer.) For his last day of his last summer before graduating college, his co-workers celebrated the milestone by taking him for a caboose ride on a local freight. While they casually, yet securely, braced themselves for the first big slack-letting/taking, they didn't mention a thing. He said it darn near threw him the entire length of the caboose and back! They all had a good laugh at his expense, and then told him to listen for it clanging ripple through multiple railcars in front of them whenever the rest of the train slowed or sped up, or transitioned between uphill and downhill grades (bam, Bam, BAM, WHAM!) And not let go after the first event! While he was better prepared and braced himself, he was still shocked by the violence of it. I'm sure the rest of the train crew were in on it too, to maximize the entertainment.

    He was the one who educated me on the extreme environmental specifications for (physical) shock, during rail transport, for our product specs, especially in hump yards.

    So, to bring this back around to relevance, a certain "slinky-ness" is actually prototypical. Cobbling together a small, battery-powered processor module with an accelerometer, and BT or WiFi to transmit the results in real time, installed in the caboose or last freight car, might be entertaining and enlightening.
     
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  19. jhn_plsn

    jhn_plsn TrainBoard Supporter

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    Well, in your day two cents was worth someth'n. :p

    That said, when one runs a caboose it's easy to just add a spring to one axle journal/point.
     
    Last edited: Apr 19, 2023
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  20. BarstowRick

    BarstowRick TrainBoard Supporter

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    That's a fact! On the two cents.

    Yep, the spring to one axle journal helps. Creates the needed drag. I've tried that with less then desirable results. It's a good place to start.
     

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