I don't often start a new thread but here goes. Join me to see where this leads and remember you can't hijack a thread...it goes where a discussion goes. Now let's have some fun. Slinky Revisited, I recently purchased from a fellow RoundHouse Gang associate, some MT boxed couplers, the ones that are truck mounted. He had cut them off and sold me a fist full of them as he is determined to body mount couplers on his N scale train equipment. He didn't know how many he had in the jewel box and I took a chance. Never mind the price was right. Turns out it was 30 each in total or 15 pairs. I had some older Bachmann tank cars that came with Craig's collection. I was determined to get them back up and running and decided this was the opportunity to do so. My other goal was to body mount these bad boys. With Gap Filling Cyanoacrylate in hand and a drill and tap I set out to make it happen. A few challenges and creative thinking, lot's of shimming and adjustments, some trim involved and I completed the task. A mission impossible or so it seemed at the start. Now to run them and this is where we revisit the alleged "Slinky" effect. I took the cars out and placed them on the layout. I noticed a bit of cushioning as I coupled the train cars. Nothing unusual, as you see this with the real train cars on the one foot to the one foot scale railroads. I brought in a pair of ATSF, Zebra stripe, Geep 9's and coupled them to the train. As I pulled forward to stretch the train and take the "Slack" out, I noted it worked the same as the big boy trains. The train continued slowly out onto the main and began to head down the hill and I noticed the train taking up the slack, pushing against the locomotives. This continued until all the cars were on the down hill run. Nothing unusual here. As the train leveled out I noted the caboose kind of halting and lurching forward. About now a brakeman would step out the back door and tighten the manual brake to create some resistance and or drag. However, in the modeling world this doesn't happen. Then it hit me the whole train was seesawing backward and forward for no apparent reason. Now we all know about cause and effect. There has to be a cause to create such action or effect. Well, my track is not level with woop-di-doos, gradual downhill and uphill gradients and to my surprise...well maybe not... the cars were simply reacting to such. On the uphill runs the train would stretch out to it's maximum length. On the downhill runs they would be bunched up and on the flat they reacted to any and all changes in the gradients. Not to mention that they reacted to any change in speed. Just like the one foot to the one foot scale. The only difference here is an engineer can control most of this from the cab. He can increase the speed if he sees the slack in the train is moving toward the cab and ease off the impact. Or he can apply the brakes on the locomotives to set the slack to moving backward to meet the slack moving forward. Tricky but it can be done. My granddad an engineer for Santa Fe said that if he could get his train up to 65 miles per hour it would all but eliminate the slack. I did see on a club layout what most of you have been talking about and I do agree it certainly looks exaggerated. However, standing next to me was a Rail, a railroad employee who said this would be controlled by the engineer but in this case the engineer wasn't watching his train. Each side of the club layout had it's own throttle pre-set and the train was running free hand. Of course under the watchful eye of the club members. I might add here that my best efforts on my home layout to keep the trains stretched out can be an energy absorbing vigil. How to solve this dilemma? Aside from removing all the springs from the couplers, which are needed to keep them centered... there isn't much we modelers are going to be able to do to cut down on the alleged "Slinky effect" or what should be referred to as "Exaggerated Slack". Well, that should cover it. Yep, I can say I saw it. Everything normal all ________ ______ (you fill it in). arghh:laugh:
Rick does your Cabooses have a spring in the wheels? If not try picking up the springs from MTL that should put some resistance and help your problem. And if you run F.R.E.D.s put the spring in one wheel of those cars & that should help too.
Is there a way to add just a slight bit of drag to each car? I suppose you'd need more motive power but that's not so bad, is it? Perhaps if all the cars are properly weighted, using a friction device on a caboose wheel or two? Maybe that won't be enough to compensate for the inertia of all the cars in the consist rolling downhill, I suppose, but it might help on straight and level track?
I weather my wheels to increse the rolling resistance. Some chalk dust up in the axle cups on the sideframes usually does the trick. If you need more resistance you can also slop some paint up in the cups as well. MT axle springs can also be used.
Excellent suggestions. Thanks for the comeback. Disclaimer: When I address someone specific here you need to know that because this is a public forum you can all tune in, give it a read and respond to it, quote it and disagree... if you so desire. That's what a public forum is for. If I intend to make this private, I will write a "Private Message." No one is left out...intended or otherwise. Nick, I do have one UP crummy that has the MT spring device and yes it helps. Looks kind of odd though. When I go to stretch the train, on start up, it will briefly stretch and stretch some more then snap forward to catch-up with the car that is moving away from it. That should spill the coffee and sufficiently diss off the conductor. Grin! "Who's going to clean up this mess," I can hear him yelling. To EMD and grant, I have a number of cars where the wheelsets create drag. I usually run these at the end of the train and it does help to stretch the train out and keep it from bunching up or see sawing. Good suggestion and it works...sort of. Caution: To much drag and it can break up the train or stringline it. I just hate picking train cars up... off the floor. Now where did that spring go?
The problem with adding resistance is that its going to be very difficult to add CONSTANT resistance, any inconsistency in the resistance I think will inversely amplify the slinky effect. Ensuring each car has as little rolling resistance as possible is the better solution. If the car has resistance, inertia is your worst enemy. It takes more force to start movement than to continue movement. So the more resistance you put, the greater force will build up in those coupler springs. When all that force is released.. slinky. Think of it like dragging a foot. That adds resistance to your own movement, but your forward movement is not going to be constant. If you eliminate the resistance as much as possible (even on the caboose), theoretically, you eliminate the inertia problem as the amount of force required to start movement is drastically reduced (reducing the tension in the coupler springs). Unfortunately, it takes just one sticky axle to mess that all up.
If slinky effect is caused by the centering spring...and that centering spring isnt stiff enough to stop it...couldnt the spring be replaced with a stiffer one...in theory? I know there is a point that too stiff a spring would cause the coupler to stay straight...esp in curves...and that could/would cause derailments. Just thinking out loud. Maybe the external springs off the new McHonker couplers is a bit stiffer...hmmmmm. .
One way to stop this would be to remove the spring and put a piece of styrene (or whatever else will fit!) in the middle of the spring. Reinstall the spring and then notice how the spring will still center the coupler, but it keeps the spring from collapsing and this will stop some of the slinky effect. Easy to do, if you can get the coupler apart! I body mount my couplers and use the 1025 kits so it is easy to do. This will take a little trial-and-error to get right.
Interesting observations Rick. What does it say about our ability to operate a model train? Engineers must anticipate the action that a train is going to take under certain circumstances and proactively / reactively make adjustments in order to prevent problems. As you pointed out other members of the crew can also make adjustments as required. So how much micromanagement does a model train require in order to operate smoothly and is it even possible? Obviously when we set our trains for continuous running we are defeating all possibilities. During hands on throttle operations, who thinks about what they could do to make the train operate more smoothly (prototypically – there I said it!)? DCC has given us some tools and there are mechanical adjustments that can be made to help with the slinky effect. Then again we can just complain about it until a better solution comes along to grease our squeaky wheels.:tb-hissyfit: Personally I tend to ignore the operating quirks (bury my head in the sand technique).:tb-cute: I’m just happy to get through an operating session without any derailments. Besides 1:1 trains do not always perform smoothly. Jerry
Like whats already been said here, I use the MT springs on the rerar most axel on my cabooses. Although, I usually don't run long trains, usually 10 cars or so, when I do, I use the spring axel trick. one of the things I have done, that seems to work well for me is to cut a turn or two out off the spring, the reduced drag is still enough to reduce the slinky effect, but not enough to string line the cars.
the mt springs on the wheels help to reduce the slinky action. from my experience i'd say one out of 20 cars needs springs on two axles. a 100 car train will therefore need 5 cars with 2 springs each. from my experience this helps to reduce the slinky action for a whole train.
Kadee was a early proponent of the springs on wheel "solution" going back to the 1970s. It was lame then and it's lame now. (Just my opionion ) I don't like the idea of having to plan to put the "breaker cars" into my consists. Hopefully a better way will come. Mark
Sounds like an oppertunity for some sort of DCC bracking system product within the cars... :tb-wink: :tb-wink: :tb-wink: :tb-wink:
The spring in the coupler is not really a centering spring although it does do that also. It is what keeps the two parts of the coupler closed. Placing a stronger spring or replacing it with a piece of styrene will turn and opperating coupler into a dummy coupler and make it so the cars will no longer kiss couple. Adding drag to the caboose is only a bandaid fix and inhibits overall train length. The amount of drag it takes to get rid of slinky will also vary with train length. A caboose may cure slinky in the back of the train but the middle may be bouncing around still. The cure is McHenry, Accumate or similar design that doesn't have a spring on the shank of the coupler at all.
One thing to remember about MTs is that the couplers are designed, from the get-go, to provide automatic uncoupling. Have you ever seen any of the demonstrators that Micro-Trains used to (still?) distribute to dealers? But how many N scalers actually use it? 5%? 10%? Maybe we're making a mistake. Instead of complaining about slinkiness, maybe we should use the tension springs that eliminate it, and implement uncoupling systems using the awesome potential built into the MT design.............. ? --Bryan "The question is not, 'What is the answer?' The question is, 'What is the question'?" --Poincaré
If this is directed at my post about using a piece of styrene, I never said remove the spring. I said to place a short piece of styrene inside the spring. Perhaps I wasn't clear on it, but the styrene will keep the spring form collapsing as much. The styrene should not take the place of the spring. Kadee (I'm not sure if MT ever did) used to include a few small pieces of metal in their packages just for this purpose.
My secret to the anti-slinky, I use a brass caboose with a bit more weight on the end, I use 2 or 3 Aztec track cleaning cars in the middle sections of the train.
