Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Magnetic uncouplers and wheelsets

3322 views
16 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    February 2017
  • From: Harrisburg, PA
  • 636 posts
Magnetic uncouplers and wheelsets
Posted by hbgatsf on Thursday, January 12, 2023 10:03 PM

I have many Kadee 308 uncouplers around the layout that work fine.  I just finished laying track for an industrial area and as I was testing at very low speeds I had problems with the magnets pulling the cars and causing unwanted uncoupling.  

Since I will only be spotting a few specific boxcars in the area an easy fix would be to replace the wheelsets on those cars.  Intermountain makes them in brass and Walthers has them with plastic axles.  I assume either of those would work.  Others just say that they are metal, and I don't see what type of metal so I don't know if they would work or not. 

Any suggestions?

Rick

  • Member since
    August 2020
  • 561 posts
Posted by Southgate 2 on Thursday, January 12, 2023 10:56 PM

The metals used in  the aftermarket wheelsets are non magnetic for the reasons you mention. They track well too, and Intermountain especially roll easier. Dan

  • Member since
    January 2017
  • From: Southern Florida Gulf Coast
  • 18,255 posts
Posted by SeeYou190 on Friday, January 13, 2023 12:32 AM

hbgatsf
I have many Kadee 308 uncouplers around the layout that work fine.  I just finished laying track for an industrial area and as I was testing at very low speeds I had problems with the magnets pulling the cars and causing unwanted uncoupling.  

For this exact reason, the only magnetically attracted parts on any of my freight cars are the Kadee trip pins.

Kadee trucks and wheels are non-magnetic.

-Kevin

Living the dream.

  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,335 posts
Posted by MisterBeasley on Friday, January 13, 2023 10:50 AM

My Intermountain metal wheelsets do seem drawn to strong magnetic uncouplers, and the new-found free rolling makes it that much harder.  I use a "scenic solution," planting a few tufts of tall field grass between the rails on sidings where I want to spot uncooperative cars.  The grass will interfere with rolling just enough to stop a slow-rolling car, but not enough to inhibit a locomotive or make it difficult to do a delayed action spot at a loading dock.

It takes an iron man to play with a toy iron horse. 

  • Member since
    September 2014
  • From: 10,430’ (3,179 m)
  • 2,277 posts
Posted by jjdamnit on Friday, January 13, 2023 2:10 PM

Hello All,

hbgatsf
I have many Kadee 308 uncouplers around the layout that work fine. I just finished laying track for an industrial area and as I was testing at very low speeds I had problems with the magnets pulling the cars and causing unwanted uncoupling.

What wheels and trucks are you currently using?

Do you have a magnet that you could test the magnetism of them?

I had a similar situation with a depressed center flat car. It would hesitate when rolling over the Kadee #321 Between-The-Rails uncoupling magnet.

After a little detective work, I discovered that the steel weight in the depressed center was close enough to the uncoupling magnets' magnetic field and would "grab" the car.

My solution was to replace the steel (ferrous) weight with an equal amount of lead (non-ferrous).

MisterBeasley
My Intermountain metal wheelsets do seem drawn to strong magnetic uncouplers, and the new-found free rolling makes it that much harder.

To explore this I took a set of Intermountain Semi-Scale (0.088" Tread Width) 33-inch HO wheelsets (#40052), mounted them in an Accurail (Plastic) Roller Bearing Truck (#165), after using the Micro-Mark HO Truck Tuner (#82838) on the bearing surfaces. 

Next, I placed a Kadee #321 HO Scale Between-The-Rails magnetic uncoupler on a section of straight and level track.

The test wheel/truck set was then pushed over the Kadee magnet and it rolled smoothly over the #321 uncoupling magnet.

I then placed the test wheel/truck set within the magnetic field of the uncoupler and the test set was not drawn to, or "held" by the magnet.

Next, I took a Micro-Mark Super Magnet (#84991) and placed it on one of the ties. The Super Magnet sat slightly higher that the Kadee #321, but not significantly. 

When I ran the test wheel/truck set over the greater magnetism of the Super Magnet the wheels/axle did grab.

hbgatsf
Any suggestions?

Intermountain makes 33" wheels (Delrin Engineering Plastic) that might help in your situation along with the Accurail plastic trucks.

If you continue to have "grabbing" issues you might think of replacing the truck mounting screws; if they are metal, with Kadee #256 Insulated Nylon Screws 2-56 x 1/2 inch.

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

  • Member since
    February 2008
  • 2,315 posts
Posted by kasskaboose on Friday, January 13, 2023 3:12 PM

jjdamnit

 

To expl wheelsets (#40052), mounted them in an Accurail (Plastic) Roller Bearing Truck (#165), after using the Micro-Mark HO Truck Tuner (#82838) on the bearing surfaces. 

Next, I placed a Kadee #321 HO Scale Between-The-Rails magnetic uncoupler on a section of straight and level track.

The test wheel/truck set was then pushed over the Kadee magnet and it rolled smoothly over the #321 uncoupling magnet.

I then placed the test wheel/truck set within the magnetic field of the uncoupler and the test set was not drawn to, or "held" by the magnet.

N

 

 

To clarify the diagnosis effort, do the following:

1. Use Micro-Mark Super Magnet (#84991)

2. If cars don't uncouple, use Intermountain 33" wheels.

3. If they still don't uncouple, then replace the problematic cars with Kadee #256 Insulated Nylon Screws 2-56 x 1/2 inch.

Is that correct?  Just trying to help others with a similar problem, or myself, who will eventually want to explore that idea.

  • Member since
    September 2014
  • From: 10,430’ (3,179 m)
  • 2,277 posts
Posted by jjdamnit on Friday, January 13, 2023 4:54 PM

Hello All,

The purpose of my exploration was to see if Intermountains' claim of their wheelsets actually being "non-magnetic" was true and, MisterBeasly statement:

MisterBeasley
My Intermountain metal wheelsets do seem drawn to strong magnetic uncouplers.

...was plausible. 

I listed my methodology so others could replicate my findings.

My father-in-law was a research scientist. He always used to say, "It's the results you don't expect that lead you to the solutions."

We have not heard back from the OP on the questions of what material the trucks in question are made of.

By using the Super Magnet, it set up a magnetic field greater than the Kadee #321, I presumed.

Not being a physicist I don't know how to quantify magnetic fields other than using a "stronger" magnet relative to the other.

MisterBeasley made an observation about "strong" magnets. My attempt was to replicate, with what I had on hand, his experience.

In a rudimentary form, I was able to replicate MisterBeasley's experience.

Hopefully, this will lead the OP to their particular solution to their problem.

As the disclaimer states, "Your results may vary."

Thank you for your follow-up inquiry and as always...

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

  • Member since
    December 2016
  • 231 posts
Posted by TrainzLuvr on Friday, January 13, 2023 6:02 PM

As I plan to use Kadee delayed uncoupling magnets on my layout, I'm also interested in these results. Specifically because I thought I would standardize on using IM metal wheels for all of my cars, but now I'm not so sure.

Has anyone tested other metal wheel OEMs like Exact Rail, Rapido, Bowser, Bachmann, Atlas...?

  • Member since
    September 2014
  • From: 10,430’ (3,179 m)
  • 2,277 posts
Posted by jjdamnit on Friday, January 13, 2023 6:25 PM

Hello All,

TrainzLuvr
As I plan to use Kadee delayed uncoupling magnets on my layout, I'm also interested in these results.

Keep in mind the OP used the #308 Under-The-Track Hidden Delayed-Action Magnetic Uncouplers.

These have a steel intensifier plate to increase the magnetic field to actuate the metal trip pin and provide "Delayed Action" to the couplers because of the increased distance from the magnet to the trip pin(s) versus the Between-The-Rails versions.

In my exploration, I used the #321 HO Scale Between-The-Rails Code 100 Delayed-Action Magnetic Uncoupler, not the #308 in question.

That's why I also used the higher-intensity Super Magnets to hopefully replicate the higher magnetic field generated by the intensifier plate of the #308.

The #321 is visible on top of the track while the #308 is "hidden" under the track.

The placement of the #308, requires a more intense magnetic field.

Which, from my exploration can have an unwanted effect on other metal components of the cars in question.

My exploration highlighted this.

Using the Between-The-Rails uncoupling magnets might not be as aesthetically pleasing but using them does not affect the metallic properties of supposedly "non-magnetic" wheelsets that arise using the under-the-track style uncoupling magnets with the intensifier plate.

My personal preference- -between aesthetics and functionality- -leans toward the functionality of the Between-The-Rails type.

Thank you all for the poignant questions.

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

  • Member since
    January 2017
  • From: Southern Florida Gulf Coast
  • 18,255 posts
Posted by SeeYou190 on Friday, January 13, 2023 8:33 PM

jjdamnit
Keep in mind the OP used the #308 Under-The-Track Hidden Delayed-Action Magnetic Uncouplers.

My preferred uncoupler option is to use the #308 not under the ties, but just underneath the rails. I remove the ties from where my #308s get mounted. This provides the most intense magnetic effect.

I usually disguise it with a grade crossing, manwalk, or deep brush build up.

Again, this makes it mandatory that the trip pins be the only magnetic item on the freight cars.

-Kevin

Living the dream.

  • Member since
    January 2009
  • From: Maryland
  • 12,852 posts
Posted by ATLANTIC CENTRAL on Friday, January 13, 2023 8:54 PM

I have not used fixed uncoupling magnets in a long time - 40 years?

I have not decided every condition or requirement regarding this on my new layout.

Most (95%) of my switching situations will be very close to the layout edge, so manual uncouplingwith small picks/tools will continue to be the order of the day there.

I do have three switching locations on the new layout that may prove to be a bit of a reach, so I am thinking that a few strategically placed electromagnets might be the answer. 

In any case I already have 800 freight cars with Intermountain wheelsets, that's not going to change.

While the Kadee delay feature does work as advertised, I have never been excited about it as an operational procedure, and I suppose a few tests with my own equipment are in order.

Sheldon 

    

  • Member since
    July 2006
  • From: west coast
  • 7,584 posts
Posted by rrebell on Friday, January 13, 2023 9:09 PM

Intermountain are non magnetic. But just to be sure I tested a whole batch with a string of 52, no attraction.

  • Member since
    January 2009
  • From: Maryland
  • 12,852 posts
Posted by ATLANTIC CENTRAL on Friday, January 13, 2023 9:18 PM

rrebell

Intermountain are non magnetic. But just to be sure I tested a whole batch with a string of 52, no attraction.

 

I was pretty sure about that too, but I do have lots of cars with steel weights - not changing them either. A review of my track plan puts the three difficult areas about 2' in from the benchwork edge. Maybe a one step box to stand on will be enough at the 46"/48" track elevation of these areas.

Sheldon

    

  • Member since
    February 2017
  • From: Harrisburg, PA
  • 636 posts
Posted by hbgatsf on Friday, January 13, 2023 9:50 PM

Thanks for the suggestions.  I am seeing the issue with Atlas and Walthers Mainline boxcars.  I will need to do some testing with other brands to see if they have the same issues.  

Rick

  • Member since
    January 2004
  • From: Canada, eh?
  • 13,375 posts
Posted by doctorwayne on Friday, January 13, 2023 11:19 PM

rrebell
Intermountain are non magnetic. But just to be sure I tested a whole batch with a string of 52, no attraction.

I have a few Intermountain reefers with steel axles but they don't seem to create much havoc, as proper positioning over an in-track Kadee magnet works just fine for uncoupling purposes.

I use the in-track Kadee magnets in my staging yards, but have installed some small rare-earth magnets in shallow holes drilled into the layout's plywood surface.  They work well for uncoupling purposes, but have no affect on steel axles, as they're almost under the rails, rather than in the middle of the track.

There are two magnets on each side, with both pairs having the same polarity on their tops, all hidden under the ballast, but marked by a post...

Wayne

  • Member since
    December 2016
  • 231 posts
Posted by TrainzLuvr on Saturday, January 14, 2023 6:18 PM

Had a thought about the in-between rails magnets, and the aesthetics of their placement.

uncoupler magnet orientation

Considering that their magnetization direction is oriented through the length, could the whole magnet be replaced with tie sized individual magnets, and then track ties replaced with them?

This way one could have full control over the area of influence and length.

  • Member since
    January 2017
  • From: Southern Florida Gulf Coast
  • 18,255 posts
Posted by SeeYou190 on Saturday, January 14, 2023 10:47 PM

ATLANTIC CENTRAL
While the Kadee delay feature does work as advertised, I have never been excited about it as an operational procedure, and I suppose a few tests with my own equipment are in order.

My first operations were in N scale, and the delayed/push-to-spur feature was amazing. I don't think picks would have worked well in N scale.

My preference for the delayed feature carried over into my switch to HO scale.

-Kevin

Living the dream.

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!