Rails, is there a good way to prevent cars from bunching and stretching slowly going down hill ? What I mean is, I guess due to rolling properties of each car, the string of them do not roll all stretched if in front of engine or all bunched closely if behind engine going down hill. They each seperately surge and drag, surge and drag..This looks so toyish..50+ years ago a MRR told me to put coupler springs in car journal boxes to create drag..But I have enough trouble with drag going up hill..Is it merely that I need all high quality trucks ? I do have several newer cars which coast forever..But I have some which roll freely but don't coast so well...Did I just answer my own question ? Or, is it something else I'm not aware of ? This is HO 2.5%-ish grade on tangent going into about 27" radius still down-hill 200-ish degree curve at 10-ish MPH.. Mark-ish...
What type of couplers are you using? It could be the spring within those and a different style coupler is necessary. If cars are light, those will bounce easily. It also helps if all cars are weighted to a common standard.
All Kadee/McHenry/other knuckle types..No, I have not weighed my cars..I have lubed them. I suppose it's the need for newer, freely coasting trucks/manufacturers.
Do consider weighting them. Light cars tend to bounce very easily. Weighted can as well, but will do so far less. Couplers- Inside the draft gear boxes, there is a post which the couplers are mounted over. If the couplers you are using have their springs behind the post, they will bounce much more easily than if the spring is in front of the post. Regardless of brand.
Weigh them, it helps. it also helps with the trucks staying on the track. The problem is mostly from the Micro Trains couplers. The have a spring in the box that allows the coupler to bounce forward and backwards. Atlas uses plastic whiskers on the sides of the shaft to align the coupler in the draft gear box. Others use variations of these.
Actually this is very prototypical, the only problem is mass and period of motion since our cars have so much less mass. Real rail cars do the same thing, but much slower by comparison. In our smaller scales this happens becaue we have very free rolling rollingstock that and soft springs in the couplers. Those above have good suggestions. I agree properly weighted cars does help a lot, but sometimes it is good to put a drag car near the end of the train. This is easy if you use cabooses... just make sure they do not roll as free and it will keep thinsg looking better. If you are in an era with no cabeese, then you will have to designate some tail end cars.. may add some freds to remind you which ones to use.
Very much prototypical. Typically you would "make a good set" on the cars (air brake reduction... 10-15-20 lbs) and transition into dynamics as needed. Unfortunately our models neither have a functioning air brake system nor dynamic braking. I have experienced this downhill motion issue on a few layouts, and in my case the issue was having too many cars pushing the engines down the hill. Once the locomotives started to transition off of the grade the bunching/stretching quit. You could examine the cars to make sure all wheels are rolling freely and there isn't too much side to side action in the couplers. I've never seen any real solution other than good rolling stock maintenance and train length control.
A snmall piece of foam rubber between an axle and the bottom of the truck will add a little bitb of friction and stop the bouncing
Adding weight is not always the answer. In answer to the OP's original question and perhaps out of sync., with the other comments. Here goes: For most model railroaders, adding weight to a train car seems to be the cure all, the absolute solution to any operational problems. May I suggest...not so. Weighing them to NMRA standards and no more, is more often the correct solution. My cars get weighted a little lighter then they recommend as that's the standard I've set for my railroad. Less is better. Or having your train cars weighted the same or proportionally the same. In other words 40 ft cars have .75 oz per car, 50 ft cars have .85 oz per car, 80+ foot train cars have 1.25 oz per train car. I do at times weigh the lead car such as a baggage car at 1.50 oz as it has to handle the reverse moves, when backing into a train station. About the "Slack" action you've been witnessing. As already said that is about as prototypical as you can get. Perhaps a bit exaggerated with our N scale equipment but nontheless prototypical. It's all in the hands of the person operating the throttle. I usually turn on the momentum feature while running my trains. This way if the throttle gets pumped and kicked up the train will change speeds gradually and I can reduce the slack action. It takes a real eye and some serious self discipline to operate trains over my mountain railroad and I love the prototypcial action of the trains. Track work is paramount to good operations as is wider radius curves. Keep that in mind as you build your layout. You may at some point in the future recognize the need to remodel and add some operational realism to your layout. Mark, Just for fun. You want to take a bus ride to Big Bear and stop in to operate my layout. Heck, you might even get a layout tour of other layouts in the valley. Let me know in advance. I don't do well with last minute..."I happen to be up here with 22 people, can I stop in for a quick second". In that case don't waste my time. hboy: Grin! Best of luck Mark In L.A
I see two options. First, and possibly best, is just as you start down the hill, stop your train, mimicing a "set". Let the train rollinto the engine just slightly, and then walk er' down the hill. Option two,mis to putmdrag on your caboose. Not so much that you straightline the train, but maybe one (shudder) plastic wheel on it to minic an applied brake. You could also do this gently witha a finger, but that involves touching your trains. Remember, the issue here isn't about car weight or trackwork, this is about our delicate dance with gravity. Give her too much lead, and we end up with the above slackaction, and at least in HO, rampant coupler springs. (yay Sergent couplers) fight her too much, and she'll tip our trains over a curve. Yes, weight does play into straightlining as well, but its less of a weight issue and more of a resistance issue. Since we brought it up, i'm getting swayed to the more is gooder crowd, only brcause lighter cars more readily try to jump bad switches than do heavy ones, which will sometimes power through them. I know a guy who has weight in his ttx well cars and then weights the containers like boxcars to assure plenty of weight. There's no easier way to stretch really thana good, gentle start.
MicroTrains recommends a small spring be placed between the wheel and journal box on an axle of the caboose (or last car of the train). This seems to work pretty well, and adds only minimal drag to the train in other places on the layout. It is much the same as setting a bit of drag brakes on a real train to prevent the same problem. I don't see why this wouldn't work in other scales as well, provided you can find an appropriate sized spring. Bill in FtL
Probably a typical coupler spring would be a bit too long, the N scale ones are bigger in diameter than they are long. Another idea might be as simple as adding wipers on the trucks to power lights or a FRED on the last car, which would also add a little drag. I know some guys that run HOn3 and that is the trick they use, because their cabooses all have marker lights. Bill in FtL
Another thing that I have noticed that can lead to this effect in HO scale, is that the engines are "cogging" IE have too much slack in the drive allowing the worm gear to shift back and forth. I know Atlas units are notorious for this as are some athearns. This makes the cars look like they are bunching than really quickly being pulled along, If you watch the engine you can see it slow down, than pick up speed. My suggestion if this is found to be the case is to put washers on either end of the worm gear to eliminate slop. I had an Atlas GP7 that cogged so bad that it could knock cars behind it off the track. After some metal washers were installed, this effect went away entirely.
