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Magnets, what have I done

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WPA
  • Member since
    April 2018
  • 140 posts
Magnets, what have I done
Posted by WPA on Thursday, March 4, 2021 7:42 PM

I never used magnet uncouplers before and diving back in N scale and I thought it would be great hands free.  Enjoyed old school Rapido uncouple as needed in the late 1970s.  Put a bunch of magnets in on my new layout and tested them with some of my old rolling stock with new wheel sets with Micro Train couplers. They worked ok and did not have any issues picking up a load and going on my way. Actual did not uncouple very easy.  Now starting to test with new Athearn cars and boy, the magnets work great, but too good.  I think pick uncoupling and easy pickup without constant uncoupling and all cars in a row uncoupling in yard outweighs the magnets.  I am still in early stages and still figuring it out.  Thinking I am going to regret not tearing the magnets out now.  

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Posted by Southgate 2 on Thursday, March 4, 2021 11:28 PM

Permanent magnets are known to create the problems you describe. Using electromagnets or finding a way to mechanically raise and lower the permanent ones (what I did) eliminates those problems.

Some people who don't use any magnetic uncoupling simply clip off the actuating pins.  Dan

  • Member since
    January 2003
  • From: Brisbane Australia
  • 568 posts
Posted by Alantrains on Friday, March 5, 2021 5:25 AM

Southgate 2, I'd be interested in your method of raising and lowering the magnet, I used a brass door hinge with fishing line used to pull it up and gravity to lower it.

Alan Jones in Sunny Queensland (Oz)

 

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    February 2008
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Posted by kasskaboose on Friday, March 5, 2021 7:33 AM

On the 1st layout, I used a magnet set.  It sat under the track in my yard throat.  It worked, but reading other similar issues with magnets makes me think twice about them. 

Perhaps the BBQ skewers is the more viable approach.

WPA
  • Member since
    April 2018
  • 140 posts
Posted by WPA on Friday, March 5, 2021 7:46 AM

Too far along to add trap door.  Cutting out spots is going to really complicate things and I can reach all areas except one tight cut between two hills.  I am in early stages of scenery so taking them out is not major, just pop them a little free and slide out.  I ran more new cars  together last night and pulled them out of the yard and they came apart and tried to pick up a new tanker from a siding and could not keep coupled no matter how slow or fast I went.  My mixed reviews with my upgraded old rolling stock fooled me.  Should have done more testing with newer cars.  Will say the McHenry couplers sure work well.  Pretty sure I am removing all but one. For as unappealing as the Rapido couplers are, my past days of using them with the electric uncoupler sure worked more hands free.  At the time I thought I was missing out on the Kadee experience.  Not so sure now.  

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Posted by Southgate 2 on Friday, March 5, 2021 4:47 PM

My method of adding liftable magnets would require a lot of cutting holes in the roadbed and subroadbed  to install them and give them room to operate. Best done in the track laying stage.Embarrassed Dan

WPA
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    April 2018
  • 140 posts
Posted by WPA on Saturday, March 6, 2021 10:03 AM

I went ahead and removed them.  Maybe I can use them on a future expansion.  Learning a lot and glad I kept it small to start.

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    January 2019
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Posted by John-NYBW on Saturday, March 6, 2021 8:33 PM

Early on in building my current basement sized HO layout I discovered having under-track magnets on the mainline was a bad idea. The slightest hesitation by the loco would cause slack and an unwanted uncoupling which became very annoying. Fortunately I discovered the problem before I had done any ballasting so it was easy to remove the magnets. Now the magnets are used only in yards and spur tracks. When uncoupling is needed for switching moves on the main or sidings, I use a manual uncoupling tool. I've tried the KD uncoupling tool, bamboo skewers, and even a small screwdriver. I haven't decided on which one I'm going to settle on. 

One problem is switching moves with passenger cars with diaphragms. I hadn't found one that is reliable. Then I read that you can temporarily just drop a between the rails magnet into place and then drive the train over it until the couplers you want to separate are over it. I've only tried it a couple times but it seems to work out. I'll need to test it a bit more  before I'll be convinced this is the solution. 

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Posted by speedybee on Monday, March 8, 2021 10:26 AM

I might have a solution for you... I was playing with magnets the other day, trying to come up with an uncoupler that can add on top of track that's already completely finished and ballasted, without having to modify track or scenery.

I used small neodymium magnets, cylindrical, 3mm diameter and 2mm thick. They were pretty cheap, about 10 cents apiece, on eBay.

I glued them, lying flat with both poles in the same direction, to a thin piece of wood (scale 3x10) such that the outer edges of the magnets are 10mm apart.

Then I glued the arrangement on top of a tie, centered in the midline of the track, but oriented on an angle such that when you're looking at it from above the top magnet is 3mm left of the bottom magnet.

Worked perfectly in a brief test on a scrap piece of track. Uncouples when you stop the train in the right spot, doesn't uncouple when just passing over it. 

This is a case where a picture is worth a thousand words, I'll take one tomorrow once I've put one on a painted and ballasted track to see how it looks in situ. I haven't decided whether it'd look better painted grey to blend in with ballast or rusty brown so that it might look like some kind of hotbox/defect detector.... I'll probably try both

WPA
  • Member since
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  • 140 posts
Posted by WPA on Monday, March 8, 2021 8:12 PM

Interesting. 

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Posted by speedybee on Tuesday, March 9, 2021 12:32 PM

Can't do painting and ballasting today, I have to fix some plaster cloth first... Anyways, I can't totally recommend this approach until I've tested it more thoroughly, but results so far are promising

  • Member since
    December 2016
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Posted by speedybee on Tuesday, March 9, 2021 2:00 PM

Did some further testing with that arrangement while plaster cloth is drying, and I've encountered the same problems as others have had with permanent magnets... some rolling stock works perfectly, while others don't :( Presumably if I fiddle around with couplers I could get them all to work, but I'd rather have a magnet solution that is less picky about couplers.

So my search for this particular holy grail continues. I've got another arrangement I'm trying out that seems better, but this time I'll refrain from going into details until I've tested it throughly with lots of rolling stock.

In the meantime I'll cross out the previously posted arrangement to avoid leading others astray

 

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  • From: Texas, USA
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Posted by PennsyNut on Thursday, March 11, 2021 3:03 PM

Just my 2¢ worth. I leave the pins entact. Do make sure they are the proper distance above rails. And use removable uncoupling ramps on tracks that are difficult to reach/usually over a foot. Place in track with two sided Scotch tape. And use the "pick" on most all track. Easy to use either. Permanent magnets have always been troublesome and not worth the time and effort to install and as you noticed. Not as reliable as they should be.

A SPF,Nuts about Pennsy,what else is there?
  • Member since
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  • 168 posts
Posted by speedybee on Saturday, March 20, 2021 10:22 PM

OK I've done more testing and my on-top-of-ties magnets work well enough that I'm installing them on all my yard tracks. There were occasional unwanted uncouplings, though only at low speed.

https://imgur.com/a/yrlXpUD

(video) https://imgur.com/a/0mk0SqF

As before, I'm using neodymium magnets 3mm diameter 2mm height, polarized in the cylindrical direction.

What I have now is two magnets, glued on top of the same tie (or equivalent height on ballast). Magnets are oriented with opposite poles up. Inside edges are 6mm apart, outside edges are 12mm apart (since each magnet is 3mm diameter). The 2mm height brings the top of the magnet about level with code 83 rails.

Rather than gluing directly to the ties, though, I've found it easier to glue the magnets to a small strip of wood so that I can get placement perfect. Then I scrape away a bit of ballast so that I can slide the magnet+wood arrangement between ties.

https://imgur.com/a/GY2XRMl

Those coffee stir sticks are perfect becase they're 6mm wide. So I cut a piece narrow enough to slide between ties, and use a full width piece as a spacer between the two magnets. Then I glue the magnets to the narrow piece of wood and remove the spacer, though it could probably stay. I used clear gorilla glue, but epoxy cement would work fine too. The magnets will definitely go flying into each other if unrestrained while the glue is curing. That's solved by two more magnets, placed on the underside of the wood, clamping the upper magnets in place. These lower magnets can be removed once the glue cures. Then a coat of brown paint to make it less ugly. The one in the photo needs a bit of a touch-up. I might experient with painting them grey too, but for now I'm happy with them.

Best part is, they're super easy to make and add or remove to already finished track.

 

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