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question on magnetic uncouplers

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question on magnetic uncouplers
Posted by Camarokid65 on Friday, January 24, 2020 10:14 PM

Hi all!

      I am using Kadee magnetic uncouplers at different locations on my layout, these are the ones that go underneath the track. They work great with one exception, albiet a biggie. When my train goes over these uncouplers, and i dont mean at a creeping speed, some cars want to come uncoupled. Seems that the reason is that as the train goes along at times there is a little slack that quickly occassionaly occurs as the engine pulls the cars, and if this happens as couplers cross over these uncouplers, the cars seperate. Is there a way to rectify this? Obviously I want to use the uncouplers and they work well when Im dropping cars off at a siding, but I dont want them doing this with a train at speed per say, lol. Will this possibly go away once I ballast?

 

Del

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Posted by SeeYou190 on Friday, January 24, 2020 10:56 PM

Any slack over a magnet, and you will uncouple.

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I piut drag on my cabooses by using Kadee caboose trucks with the electrical pickup. These seem to add just enough drag to stop most unwanted uncouplings.

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I would love to hear a better solution if anyone knows of one.

.

-Kevin

.

Wink Happily modeling my STRATTON & GILLETTE RAILROAD. A Class A line located in a personal fantasy world of semi-plausible nonsense on Tuesday, August 3rd, 1954.

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Posted by MisterBeasley on Friday, January 24, 2020 11:22 PM

I have issues with strong magnets actually causing slack, although usually when just spotting a car or two on a siding.  This became a problem when I upgraded to metal wheels and metal axles.  The magnets pull the uncoupled cars back to the magnet because those nice, smooth, low-friction wheelsets offer little resistance.

I planted a couple of tufts of field grass between the ties on the siding, which stopped the frre-rolling cars and restored smooth uncoupling.

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

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Posted by Camarokid65 on Friday, January 24, 2020 11:55 PM
Kevin, how does this work at creating drag with the Kadee trucks?
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Posted by gregc on Saturday, January 25, 2020 5:12 AM

controllable uncoupler such as RailCrew are more appropriate on mainline tracks

greg - Philadelphia & Reading / Reading

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Posted by gmpullman on Saturday, January 25, 2020 5:48 AM

SeeYou190
I would love to hear a better solution if anyone knows of one.

A: Kadee electromagnet uncoupler.

https://www.kadee.com/ho-scale-uncouplers-c-274_280_300/309-ho-scale-undertheties-delayedaction-electric-uncoupler-kit-p-340.htm

(Kadee upgraded their website Yes

B: I recall an article where the permanent magnet uncoupler was mounted on a hinged block under the roadbed. When you wanted to have the uncoupler for use you would pull a string or wire and the hinge would allow the magnet to lift to the proper under-track position for use.

Normally the uncoupler would swing free and not be in proximity of the track roadbed.

I suppose you could use the motion of a Tortoise to raise or lower the magnet as well.

Good Luck, Ed

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Posted by SeeYou190 on Saturday, January 25, 2020 7:47 AM

Camarokid65
Kevin, how does this work at creating drag with the Kadee trucks?

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The Kadee caboose trucks with electrical pick up are not as free rolling as the normal kadee trucks.

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I have struggled with my cabooses for years. All my cabooses in the Fleet of Nonsense are brass. Kadee trucks could make them short out on curves if the journal boxes contacted the steps.

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I tried using Tichy plastic caboose trucks with Intermountain steel wheels, but these rolled so freely, that accidental uncouplings of the caboose were common.

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I switched these to the plastic Tichy wheels, but still had some issues.

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I tried to make axle brakes out of phosphor bronze stirps, but could not get the adjustment to where I was happy.

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When I was in N scale, kadee made springs to restain the caboose truck axles, but there is not a similar product in their HO scale line.

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gmpullman
Kadee electromagnet uncoupler.

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I plan to use these on mainline trackage and in a couple of strategic areas. I would love to activate them with a momentary push button and have them set on a 20 second timer.

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gmpullman
I recall an article where the permanent magnet uncoupler was mounted on a hinged block under the roadbed. When you wanted to have the uncoupler for use you would pull a string or wire and the hinge would allow the magnet to lift to the proper under-track position for use.

.

I have experimented with an idea a user posted on the forums for turning the Kadee 308 uncoupler 90 degrees when not wanted. It seems to work well, but the whole thing with be under the ballast when the layout is complete and non-servicable.

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I would love Kadee, Circuitron, or Rix to make a kit to do this.

.

-Kevin

.

Wink Happily modeling my STRATTON & GILLETTE RAILROAD. A Class A line located in a personal fantasy world of semi-plausible nonsense on Tuesday, August 3rd, 1954.

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Posted by peahrens on Saturday, January 25, 2020 8:40 AM

gmpullman

 

I'll second Ed's suggestion on the electromagnetic Kadee's.  I had the same issue, routine mainline uncoupling.  I had installed 3-pair vertical cylinder magnets, but the same issue.  I decided to try the electro's and am glad I did.  It is a bit of a project, but a satisfying one.  

 Uncouplers4 (2) by Paul Ahrens, on Flickr

  Uncouplers3 (2) by Paul Ahrens, on Flickr

 

Paul

Modeling HO with a transition era UP bent

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Posted by gregc on Saturday, January 25, 2020 9:13 AM

gmpullman
I recall an article where the permanent magnet uncoupler was mounted on a hinged block under the roadbed. When you wanted to have the uncoupler for use you would pull a string or wire and the hinge would allow the magnet to lift to the proper under-track position for use.

it looks like a controllable uncoupler can be made if two magnets are mounted on a plate directly under the track that can be manually rotated with a push rod. 

greg - Philadelphia & Reading / Reading

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Posted by RR_Mel on Saturday, January 25, 2020 9:22 AM

I also use the Kadee Electro Magnetic Uncoulers in pairs like Paul.  As he said it’s a bit of work to install them and they take a chunk of power to operate them but they work GREAT!
 
I use mini toggles on my control panel and the originals didn’t last very long.  I ended up using relays to switch the current, I didn’t want large toggles on my panel.
 
 
EDIT:
 
I made a couple of moving magnets and they also work good, the post on my had blog disappered when I went to link to it.  I did a redo of it as close as I could remember.  For those interested in seeing what Mel the dingbat trainguy does when he is stuck at the workbench check it out:
 
 
 
 
Mel
 
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
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Posted by John-NYBW on Saturday, January 25, 2020 10:02 AM

I fought this problem from the start and finally gave up and removed the uncouplers from the mainline and only use them on sidings, spurs, and yards. To uncouple on the main, I use bamboo skewers which are cheap. I quickly got the hang of uncoupling manually with the skewers. Kadee makes a tool for doing this and in a pinch you can use a small flathead screwdriver.  

Kadee does make electro-magnetic uncouplers that only uncouple when they are turned on. That's fairly expensive and they are quite bulking. In my case, it was not practical to put one at all the places I would need one for both trailing and facing point spurs. 

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Posted by Medina1128 on Monday, January 27, 2020 10:48 AM

I insert one of the Kadee knuckle springs in the axle pocket in a truck of my cabooses (cabeese). This creates enough drag to keep the cars from going slack.

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Posted by Southgate on Monday, January 27, 2020 3:41 PM

I twice posted a way to make and install permanent magnet uncouplers in a layout below the track that can be left in a lower position, raised when you want them. They work extremely well, never an unwanted uncoupling. Invisible on the layout.

I got only one comment, saying something like they look cheap. (unlike bamboo skewers?) Dan

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Posted by kasskaboose on Monday, January 27, 2020 7:21 PM

Great discussion topic.  Is there a difference between using electromagnetic coupling devices on the mainline than yard/sidings? 

I'm planning on putting some in the throat of a yard.  On the 1st layout, I used a metal sheet with small cylinder-shaped magnets.  Think that the OP could use them on the mainline?  I forgot who made them.  Kaddee? 

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Posted by snjroy on Wednesday, January 29, 2020 8:22 AM

gregc

 

 
gmpullman
I recall an article where the permanent magnet uncoupler was mounted on a hinged block under the roadbed. When you wanted to have the uncoupler for use you would pull a string or wire and the hinge would allow the magnet to lift to the proper under-track position for use.

 

it looks like a controllable uncoupler can be made if two magnets are mounted on a plate directly under the track that can be manually rotated with a push rod. 

 

The Rapido uncoupler basically works like that. Works very well. In all cases, coupling and uncoupling at command works better when using KD couplers, installed at the proper height, well lubricated and on a flat surface.

Simon

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Posted by Marc_Magnus on Wednesday, January 29, 2020 12:41 PM

This is a design of using Kadee permanent magnet a friend of mine designed some times ago

It's cost nearly nothing, works great and undesired uncoupling over them are gone for ever

In fact Rapido use a similar way except they concealed two magnet in a box.

Our design is manualy operated, but could be easily powered with a servo or an Hankscraft display motor.

 

 

Then years ago, a good friend of me, was in the way to install permanent  Kadee Magnet uncoupler on his layout.

He made a mistake when putting one in place, but this mistake was in fact like an "EUREKA".

The magnet does'nt work, and after a few observation, the conclusion was so idiot, just before us !

 

You can imagine how it's simple, and after this mistake we have speak a lot about this so idiot way to use magnet, we never understand who it's possible such so simply trick was never used or proposed for a permanent uncoupler for Kadee couplers or clones.

 

When you put a  Kadee magnet  in the normal position under the track, the couplers which comes over the magnet uncouple, we all know it, the only trouble about permanent magnet is when a  train is passing over the magnet, sometimes a car uncouple even if you are not asking to uncouple.

 

And........surprisecool   smileylaugh    enlightenedenlightenedenlightened   yes

 

If you just turn under the track the magnet 90°, no more uncoupling, because, the magnet field of the magnet need to be aligned between the two rails of the track to uncouple , if you move this field 90°, the field has no more effect on the couplers when he is perpendicular to the track.

 

No need of a system which need to activate the  lowering of  the magnet, or with a hinge and all the quiet clever mecanism which were proposed over the years  since Kadee couplers exist.

Before you take a look of the pictures, if you have the Tools, install the device take no more time as a conventional installation,it's may be quicker;  building the little device which hold the magnet no more than 20mns, but you have a permanent uncoupler for few bucks which uncouple when you are asking for. Adjustement are minimalist.

 

Drill a hole with a circular saw in the axe of the middle of the track.

The round countours of the magnet are done whith a sand belt when the magnet is glued on the metalic plate.

the device itself is just a magnet glued on  his metallic plate, rounded as mentionned,  a small hole in the center of the metallic plate, a brass rod with a few nuts and washers to adjust the height, a small piece of plywood as an under the roadbed support, a few hole and the device is ready to go under the track.

If you are asking  to ballast the hole area, a piece of extremely fine "mika" is put Under the track to close the hole; I use plastic from translucide folder used to put "tax papers and invoice " as a plug for the hole, thickness is under 0,01 mm and don't affect the magnet field.

There are two way to move the magnet, a arm, fixed of the outside of the magnet with a simple lock system, like figured on Jacques pictures, or directly on the center shaft, with a arm which give the move ( the way I do).

Since the rounded magnet is the same diameter as the drilled hole, nearly no adjustment.

There is no alteration  of the "magnetic" qualities of the magnet doing this way.

The system is ok for all scales; you can substitue Kadee magnet with your own as I do, see pictures.

The rotary movement is done with a small arm attached to the shaft or on the magnet, a cable or any design of push rod will work, you say easy ?

And if your magnet is really far from the edge of the layout, you can easily consider the use of a servo or an Hankscraft display motor to turn the magnet only 90°; a Tam valley servo turnout control can do the trick; this way a DCC working one is also possible.

 

Enjoy....., and a big thank you to my friend Jacques Leplat; hope he make such other "EUREKA" mistake in the future !!!

 

This is a magnet which is placed in the conventionnal way Under the track ( Nscale), coupler is open over the magnet

Second picture, the magnet is turn 90°, no more uncoupling because the magnet field is not in the good way

A device which use a HO Kadee permanent magnet, ( J. Leplat pictures)

 

First drill a hole Under the track with a disk saw (J. Leplat pictures)

Put the magnet glued on the metalic plate in the hole ( J. Leplat pictures)

This is a view of the device Under the roadbed ( J. Leplat pictures), any device, from a push rod to a servo can push the small brass rod to turn only 90° the magnet

Following a sketch of the system and how it works,

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Posted by MisterBeasley on Wednesday, January 29, 2020 2:03 PM

For those who use the Kadee electromagnet, they sell a power supply that will handle the hefty power demand of these magnets.

Kadee doesn't make these supplies.  If you look online, you can get exactly the same supply for a much lower price.

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

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Posted by NittanyLion on Wednesday, January 29, 2020 2:12 PM

Get yourself two 1/8 diameter cylinder neodymium magnets. Drill two holes side by side just inside the rails. Jam one magnet with the north pole up in one hole and the south pole up in the other.

The field is strong enough to uncouple precisely spotted cars, but small enough that your moving train will be in and out of the field before the couplers can disengage from the slack. 

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Posted by SeeYou190 on Wednesday, January 29, 2020 5:50 PM

MisterBeasley
a power supply that will handle the hefty power demand of these magnets.

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I power mine with a huge transformer out of an old UBS.

.

What I really need is a timer that can be activated with a SPST momentary puch button and keep the magnet energized for twenty seconds.

.

-Kevin

.

Wink Happily modeling my STRATTON & GILLETTE RAILROAD. A Class A line located in a personal fantasy world of semi-plausible nonsense on Tuesday, August 3rd, 1954.

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