Operations with Magnets

Discussion in 'Model Rail Operations' started by Gary S., Apr 11, 2007.

  1. MasonJar

    MasonJar It's not rocket surgery

    Thanks for the kind words Gary!

    If I were you, and they seemed like a decent bunch, I would get back in contact with the club. Often there is a lot of focus on the layout, and not so much on "membership maintenance", and so care and feeding of potential new people falls by the wayside. My guess is that they assume you will show up if you are interested.

    As for a poll, click the "New Thread" button in whatever forum you think is appropriate, and then scroll down below the main message box. There will be a check box for "Yes, post a poll" along with a few options. So type your message in, and before posting, click the Poll check box - then, follow the instructions. If it does not turnout the way you want, just let me know and I can modify it or delete it as you wish.

  2. Gary S.

    Gary S. Senior Member

    You are probably right. I figure they lost the paper with my email, or were just so busy that they forgot. I should go back over there again. They have a huge layout that snaked all around the building and is set in modern times in New Mexico. The backdrop painting is fabulous, I mean whoever painted the low hills/desert terrain/sky was an ARTIST. All the trackwork was in but lots of the scenery and structures still needed to be built.
  3. brakie

    brakie Active Member

    Gary said:Seems this forum isn't getting near as much action as I had hoped for.
    Gary,I do my best topic thinking track side brtween trains so bare with me..In the mean time you are doing a good job..Keep up the good work.:thumb:
  4. Gary S.

    Gary S. Senior Member

    I added more weight to a dozen of my boxcars so I could test them out over the magnets. Remember, this is HO scale. I took the weight of the 40 foot cars to 6 ounces. NMRA standards would call for about 4 ounces. Even though I haven't been having much problem with unwanted uncouplings on properly weighted cars, I just wanted to see how overly weighted cars would do.

    I put the 12 over-weighted cars on the track with a loco, and repeatedly ran them back and forth across a permanent magnet under the track. I experienced zero unwanted uncouplings.

    I think the heavier cars will help in all aspects of coupling and uncoupling. However, I have one negative to report. To get the 12 car train moving, I had to crank the throttle up pretty good to get the train to move, and as soon as it would start rolling, it would kinda lurch up to speed, as in the friction would go down as soon as the initial drag of the train was overcome. I'm not real happy about this. Now I understand why free-rolling cars are desirable. It allows the loco to creep up to speed from a stand-still, and to pull a train very very slowly without stalling. It is my opinion that the loco manufacturers need to change the gear ratios in the locomotives, cutting the top speed about in half, which would give much more low end power and speed control.

    More experimentation is to come, perhaps tomorrow I will do a full-fledged operating session with the heavier cars.
  5. doctorwayne

    doctorwayne Active Member

    I've found that the main disadvantage to heavier cars is their effect on loco performance when a grade is encountered. However, I feel that operation can be enhanced with heavier cars if operating practices are modified. Starting a reasonably long train with normally weighted, free-rolling cars can often result in false uncouplings as the train passes over a track magnet. If the loco stutters, even momentarily, on a turnout, or slight undulations in the track cause the free-rolling cars to bunch up due to slack run-in, couplers over the magnet can part. Part of the key to starting a heavy train is to follow prototype practices, and "take slack" (back the loco into the train to bunch the coupler slack - coupler slack on our model trains is proportionally greater than on the prototype, by the way). When the loco starts to move forward, very slowly, the weight of each car is added individually to the load, and this should occur throughout the length of the train, with no sudden increase in speed. This requires both smooth-running locos and a control system that offers power with control. My normal power source is an MRC ControlMaster 20, with a walk-around controller. This power source will power pretty much any or all of my locos, including multiple locos on heavy trains. However, the controller, in my opinion, is a bit heavy-handed, and very touchy to speed adjustments. On a very heavy train, this is not a problem, as the weight of the train tends to smooth things out. On a shorter train of heavy cars, or a longer train with a mix of light and heavy cars, this does present a problem, as the lighter cars respond more quickly to throttle adjustments. Slack run-out and run-in can occur at the same time in different parts of the train, even on level track. Passing over an uncoupling magnet usually yields interesting results. :rolleyes: If I need to mix light and heavy cars (well under or over recommended weights), I try to place the lighter cars at the rear of the train, where this unpredictable slack action will have little effect on the rest of the train. This also makes the chance of "stringlining" on curves less likely.
    Changes in grade, both up and down, introduce slack action into the train, and again, with heavy cars and careful operation, train handling can be done quite prototypically.
    The introduction of helper locos on the rear of a train will necessitate even more careful operation, but if car weights are fairly consistent for the entire train, it can be interesting to watch the point of neutral slack move through the train dependent on which end of the train is on a grade, either up or down. Introducing a lighter than normal car into a train with motive power on both ends is asking for trouble.:curse:
    I also have two different types of SCR throttles, which run from an AC power source. These offer excellent speed control (one even has a mutiple-position brake, which allows the operator to set the speed, then control the train with the brake), but unfortunately, these will not put out enough power to run multiple locos on a heavy train, especially when a grade is encountered.
    I have a friend whose philosophy is to add weight until the trains will stay on the track, :D and, having operated on his layout several times, almost always derailment-free, I can see some merit to this idea. I once scratchbuilt a boxcar for him, and knowing his methods, weighted it to about 7 oz.: it wasn't the heaviest freight car on his layout, but at least it wasn't the lightest.;) He preferred his passenger cars the same, giving true meaning to the term "heavyweight": most were between 10 and 15 ounces, with the majority at about 12 or 13 oz. I weighted some of my own passenger equipment to these same standards, which makes for a very solid-rolling train, but later brought them back to more conventional weights when I occurred to me that trucks with plastic sideframes would eventually experience premature "bearing failure". Most of his cars had all-metal trucks. It was a very impressive sight, knowing the nature of the rolling stock, to see several passenger trains (and a few freights, too) running off the miles, derailment-free, with 5 or 6 locos on the headend, trailing 15 or 20, or even more, Pullmans, or an equally long freight. Operations here were strictly running trains though, with no grades, and multiple track continuous running.

  6. Gary S.

    Gary S. Senior Member

    Thanks for the commentary, Wayne.

    When I was running the heavier cars last night, the loco would move forward when there was slack in the couplers, taking the slack and gradually adding the drag of each car. But it would get to the point where when 8 or 9 cars were moving, and the 10th or 11th were added, the loco would stop and I would have to throttle up. Maybe this is actually prototypical? With the lighter cars I have gotten used to, I had adjusted the CVs in my locos so that just barely opening the throttle would make the train creep along at a slow speed. But in the real world, the engineer has to pay attention and adjust the throttle as the train begins to take up the slack in each car?

    So as I start the train with slack, I need to keep adjusting the throttle up as the slack comes out of the couplers one at a time?
  7. doctorwayne

    doctorwayne Active Member

    Sorry, Gary, I forgot that you're running DCC. :oops: Your controller is increasing the power to keep the train moving, but not increasing the speed (if I understand the operation of setting the CVs), but eventually the loco has no more pulling power available at that speed. I think that the problem is that the electronics are simulating the effects of a heavy train, so when the train actually is heavy, the settings are "overwhelmed". This is the same reason that I've never liked the momentum setting on a DC throttle. I'm not really sure what to suggest, as I know very little about DCC. I spent all of my time (and most of my money) :rolleyes: altering my locos so that any one will run well with any other one, with good pulling power and low end speed. As my train begins moving, I apply more power, both to get the whole train moving and to pick up speed. Each minute (especially with DCC) increase in power will by offset by the added resistance of another car, until the whole train is in motion. If your controller gives you a fine enough adjustment, you should, once the entire train is moving, be able to maintain a low speed if you wish. However, any curve or grade that introduces more rolling resistance than offered by the train itself will result in the train slowing or stopping. The trick, at least with DC, is to anticipate when to apply more or less power.
    This may be a dumb idea, but is it possible to set the CVs so that they don't alter the starting voltage (and speed) of your loco from whatever its capabilities would be on DC? My understanding of setting CVs was to get different locos to start and move at the same speed, with the same throttle setting for all, thereby getting multiple locos to work more closely in unison. Obviously, if the loco normally does jackrabbit starts, it needs the benefits achieved through setting the CVs, but most modern locos come from the factory with pretty good low speed characteristics and a low starting voltage.
    Sorry I can't be of more help.

  8. Gary S.

    Gary S. Senior Member


    I just came back in from playing around with this. My decoders are programmed to not do the momentum effects, so no problems with that.

    Discovered some interesting things. Since I was armed with the knowledge of the starting charactaristics of the heavy train, I was able to use the throttle for better control and I was pretty happy with what I could achieve.

    I ran three different locos with 14 of the heavy cars.

    Athearn GP35 (the loco weighs around 12 ounces): This loco did well with low speed starting, but as I ran it around the layout through curves and turn-outs, I could hear the wheels actually spinning = losing traction at times.

    Athearn CF7 (I added weight, about 14 ounces in the loco): didn't seem to have the low end "crawling" speed like the GP35, but it didn't spin the wheels either. I was able to control the starting speed with the throttle in a manner that was acceptable to me.

    Proto2K GP30 (this one is heavy from the factory, over 16 ounces I think): beautiful low end power, the heavy-weight cars seemed to not even affect this one. When I first got this one, I wasn't overly happy because it had the cracked gear problem and that sort of jaded me, but now this thing is great!

    And, I guess that running two locos together would achieve very good results with the heavy train. I have a couple of CF-7s that I was going to use together anyway. That may be just the ticket!
  9. Gary S.

    Gary S. Senior Member

    The point is, as the train begans to move, I need to gradually give more throttle as the drag becomes greater.

    Is it possible, or does anyone make a kit to lower the gear ratio of the Athearns?
  10. Dansco

    Dansco Member

    Has any one tried pices of mono filiment (fishing line) poking up between the rails just far enough to catch the axels? This would help in creating drag which shoud keep couplers tight.
  11. Gary S.

    Gary S. Senior Member

    Very interesting. Hadn't looked at the problem from that perspective. I would think, though, that it would be better to focus on the rolling stock. I could be wrong.
  12. Nomad

    Nomad Active Member

  13. Gary S.

    Gary S. Senior Member

    Loren, somehow I missed your post. All I can say is that is exactly what I am wanting. So yours worked out with no problems? And you would recommend them?

    As soon as you reply in the affirmative, I am going to order sets for all four of my Athearn Locos.

    With the DCC, I have set the CVs for max speed way down to give a realistic top speed. Out of the box, these things run way too fast, especially for a switching railroad like mine. Having reduced gearing would enable me to use the entire range of voltage and still have a realistic top speed. :)
  14. Gary S.

    Gary S. Senior Member


    After having run the trains for another hour this evening, I have decided that I like the heavier cars and the way the locos react. I think it adds to the realism, and I got the hang of controlling the power for more realistic starts. And I think Loren's suggested gear exchange with the lower ratio may be the ticket for even better running.

    No unwanted uncouplings, wanted couplings went without a hitch, and the weight of each car is aesthetically pleasing in my humble opinion. Since my trains are generally no longer than 12 cars, I shouldn't have any of the "stringing" issues where a car gets jerked off a curve and such.

    Hmmm.... What about the flatcars? Can I get them up to 6 ounces?
  15. Nomad

    Nomad Active Member

    Gary, if you want to reduce your low speed I would reccomend them. I don't know if they will help with what your doing now.
    Mine worked out great. Slow speed was greatly improved over the original gears. Easy to install to. It does seem to be a little noisier though. If you do get them, I will be glad to give you pointers from what I learned, just let me know.

  16. Gary S.

    Gary S. Senior Member


    I am going to get them. This should help greatly in that it will give the loco more torque at low speed, like starting a car in first gear versus starting it in third gear.
  17. Nomad

    Nomad Active Member

    Very definatly. If I start my loco to fast, I can actually see it torque, whereas the standard geared locos just take off like a rocket.
    P.S. it was also suggested to me that I remotor, but I have not seen the need to now.

  18. Gary S.

    Gary S. Senior Member

    Looking at the diagram from the gearing kit, it seems a pretty easy install. Comments?
  19. doctorwayne

    doctorwayne Active Member

    Gary, Ernst makes a re-gear kit for Athearn diesels, although I don't know if there's something available for all models. Their original offerings were for switchers or geeps. I used one in the loco pictured below, and while low speed is improved, this loco will not run with any of my other switchers.



    This loco pulls about the same as my other, lighter, switchers, because it's also equipped with Tomar pick-up shoes, which add a little extra drag. Loco weight is 13.75 oz.

    The loco below has a smaller motor, is a bit lighter, at 13.25 oz., and still has the stock Athearn gears. It pulls slightly better than the NW-2, and has room for more weight, something that was just recently added to the 53. This loco will run well with all of my steamers and other diesels, too, so is much more versatile.


    Low speed control is good with these diesels, too, so the 53 may eventually get its old gears back. I don't plan on having any yards, other than staging, so a loco that's able to m.u. with others would probably be more useful than a dedicated switcher.

  20. doctorwayne

    doctorwayne Active Member

    I'd forgotten that I recently bought a copy of the latest Walthers catalogue: I looked up Ernst and found that they offer re-gearing kits for older 4-axle diesels, older 6-axle diesels, the "Hustler", and the RDC. They also have a kit for the SD40-2. My guess is that the newer offerings from Athearn are equipped with more suitable gears right from the factory.


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