N Scale freight cars jerking, how to fix?

[Sparky]

Ok, so I'm just now starting into N Scale.  I recently purchased a proto lifelike/walthers 2-8-8-2, it appears new never ran. I did a test run with a few micro trains box cars as you can see in the video the box cars jerk back an forth.  Does anyone know what could be causing things and how to fix? The 2-8-8-2 seems to run fine although it has a slight hum to it.  I have a Bachmann K4 and the cars jerk as well, just not as bad.

Here is a video to show what I mean. 

Thanks

[Chris333]

It is the play in the couplers. They make a small spring to put on the axle of the last car (caboose) it creates slight drag to fix the slinky effect.

[mmagliaro]

If you search for "slinky" in this forum (and online) you will find lots of discussion about this phenomenon.  Like Chris said, it's just a fact of life with Microtrains couplers, and there are various ways to alleviate, but not completely eliminate, the problem.  The resistance spring added to the wheelsets in the caboose is one way.

Congratulation on scoring a Lifelike 2-8-8-2.  I think it's the best N Scale articulated engine ever made.  Ya done really well choosing that one.

[Sparky]

It is the play in the couplers. They make a small spring to put on the axle of the last car (caboose) it creates slight drag to fix the slinky effect.

They make..  as in micro trains?

Thanks for the tip..

Sparky

[peteski]

Congratulation on scoring a Lifelike 2-8-8-2.  I think it's the best N Scale articulated engine ever made.  Ya done really well choosing that one.

Well, that depends on which release. The original Life-Like (DC) version had no traction tires and was rather poor puller. It had no tender pickup either.  When Walthers took over Life-Like, they updated the model with traction tires, better electrical pickup and a QSI sound decoder. Those are very nice models.

But the Athearn Big Boys and Challengers are also very nice models of articulated locos. So are the Intermountain Cab Forwards.

[peteski]

They make..  as in micro trains?

Thanks for the tip..

Sparky

Correct.
See https://www.micro-trains.com/n-2-truck-restraining-springs-1953-12-ea-00112002

[Sparky]

If you search for "slinky" in this forum (and online) you will find lots of discussion about this phenomenon.  Like Chris said, it's just a fact of life with Microtrains couplers, and there are various ways to alleviate, but not completely eliminate, the problem.  The resistance spring added to the wheelsets in the caboose is one way.

Congratulation on scoring a Lifelike 2-8-8-2.  I think it's the best N Scale articulated engine ever made.  Ya done really well choosing that one.

Thanks, I'll do that.  Yeah I always wanted to get one once I saw it listed on the bay.  I was watching one, same as the one I got and it sold for 760.00 I couldn't afford that, so I kept looking and someone listed similar as new with a start of 295.99.  I got it for 289 including shipping.  I think I got a deal since it runs great, it is slightly louder then my other steamer, but I'll settle for that, I could probably turn up the volume and you wouldn't hear the hum it makes.  I love it though.

Sparky

[Sparky]

Correct.
See https://www.micro-trains.com/n-2-truck-restraining-springs-1953-12-ea-00112002

Thanks a ton for the link.

[ednadolski]

I did a test run with a few micro trains box cars as you can see in the video the box cars jerk back an forth.  Does anyone know what could be causing things and how to fix?

Classic Micro-Trains couplers pogo effect.  It's fundamental to the MT coupler desing, you can always find a speed that will cause the couplers to resonate because the springs are part of the axis of motion (by design).

Another example:

Notice that the effect is cumulative, so it is worse at the cars at the end of the train.


The fix?   Don't use couplers with springs in them, but alas that is not practical for most folks.


Ed

[ednadolski]

They make a small spring to put on the axle of the last car (caboose) it creates slight drag to fix the slinky effect.

More of a 'mask' than a 'fix', and even then just a partial one.  Not much use for long trains or switching moves (as your case with just the two cars).  And adding too much drag can introduce other problems.

Ed

[Doug G.]

There's another fix I remember reading about in MR years ago. The trick is to put a dab of grease in the coupler pocket spring area to damp the spring but still let it center the coupler. The writer of the article claimed it worked but I never tried it.

Doug

[central.vermont]

There's another fix I remember reading about in MR years ago. The trick is to put a dab of grease in the coupler pocket spring area to damp the spring but still let it center the coupler. The writer of the article claimed it worked but I never tried it.

Doug

Doug that's an interesting idea that I have not heard of before!!
That's something that needs some investigating.

Jon

[MK]

The added grease can be a potentail magnet for dirt and debris and an eventual gummed up coupler.

[garethashenden]

While the slinky effect is intrinsic to all Micro-Trains couplers, some bounce while being pulled, others bounce while being pushed. There are two basic designs, ie with the spring between the post in the coupler box and the knuckle, or behind the post, away from the knuckle. The first type is 1015s, the second 1025s. When two 1015s are coupled together and being pulled, the force goes from the coupler to the post, then to the car. The spring is just along for the ride. These won’t bounce when being pulled, but will bounce when being pushed because now the forces are going through the spring. The inverse is true of the 1025. When being pulled the force goes through the spring and the car bounces, but when it is being pushed the forces go through the post and the car doesn’t bounce.
Most, if not all, of Micro-Trains’ truck mounted couplers follow the 1025 design and bounce when being pulled. You also can’t really just remove the springs because they both hold the coupler halfs together and keep it centred so that cars will easily couple with each other.

[Sparky]

Classic Micro-Trains couplers pogo effect.  It's fundamental to the MT coupler desing, you can always find a speed that will cause the couplers to resonate because the springs are part of the axis of motion (by design).

Another example:

Notice that the effect is cumulative, so it is worse at the cars at the end of the train.


The fix?   Don't use couplers with springs in them, but alas that is not practical for most folks.


Ed

Wow, I thought mine was bad, your bouncing is a lot worse..