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Picture below is showing Kadee 805 couplers over the hidden super magnet uncoupler.  The couplers on these two cars have stiffer draft gear box springs so that the coupler head remains on center line when over the magnets - disabling the Kadee delayed action feature I don't use (or want) on my mine branch.

non-delay action couplers over super magneted

This photo shows two different  cars equipped with the standard soft draft gear springs over the uncoupler.  Note that the coupler heads are displaced left and right off the center line of the car - ready for a delayed action push of the uncoupled car.

delayed action couplers over super magnet

The hidden super magnet uncoupler is to the left under the ballast, the standard Kadee uncoupling magnet is to the right.  The weed marks the location of the hidden magnets.

comparing ramps after ballasting


comparing ramps after ballasting 2comparing different uncoupler magnets

6 super magnets located on drywall screws where a Kadee magnet used to be located.  If one wanted a larger uncoupling zone you could add additional pairs of small magnets

uncoupler locations

The photos show my initial installation of a neodymium "super" magnet uncoupler in a yard on my railroad.  For context - Pennsy's Oceola Mills was a coal collection yard serving over 50 mines in Clearfield county, PA.  On my railroad it sits at the end of a representation of Pennsy's Tyrone and Clearfield Branch serving 4 tipples and several industries.  Operations on the branch can keeps a crew of 2-4 busy for several hours.   I need highly reliable hands off coupling and uncoupling as reach issues and obstacles make use of uncoupling picks impractical.  First several words about couplers.  Until recently I ran the railroad with a wide mix of Kadee (804,805, 745), AtlasO (at least 5 versions), Weaver (2 versions), and Central Locomotive Works magnetic couplers.  While they all will couple with one another reasonably well hands off uncoupling over magnetic ramps was unreliable.  For smooth operation I decided to standardize on one coupler type - the initial target being the hopper car fleet.  My first idea was to standard on the new metal Kadee 700 series couplers.  But as posted on the earlier thread I soon realized l needed insulated (plastic) couplers for the pilot beams on brass 2-8-0's serving the branch .  Plan B was to standardize  using Kadee 804 (plastic) and 805( metal) couplers.  After retrofitting about a third of the hoppers with Kadee 800 series couplers we ran operational tests at the mines, yard, and main line interchange tracks.  The Kadee 800 couplers performed well but I realized we weren't using the delayed action uncoupling feature, and the additional back and forth moves required to couple to a car standing over an uncoupler was annoying, not to mention un-prototypical.  I ran some additional tests with cars equipped with stiffer draft gear springs in the Kadee pocket.  This immobilized the delayed uncoupling feature by restricting some of the lateral coupler displacement. I am pleased with the result  - the cars track well, couple and uncouple reliably, and have slightly reduced lack action.  Stiff draft sprung Kadee 804/805 couplers and hidden super magnet uncoupling ramps will become my new standards.

Now for uncoupling magnets.  Up till now I used Kadee 811 between the rails uncoupling magnets.  They work fine with Kadee couplers but their appearance is a big negative - especially if you have more than just a few (I had over 30).  I saw on the internet that some HO'ers were using hidden  neodymium "super" magnets in lieu of between the rail Kadee magnets - leading to my earlier post about using them in O scale.  Dan's response and video led me to test using 2 rows of 3mm x 8mm sitting on adjustable height drywall screws.   I installed them in a location where the ties had been cut away to accommodate a Kadee 811 uncoupler.  In new locations one could use a 8mm drill, or a Dremel bit like in Dan's video, to clear space between the plastic ties.  The super magnets worked even better than the weaker Kadee 811 uncoupler, looked far better, and Can be bought at a much lower cost.  Below are shots of my install in the Oceola Mills yard.  In the photos you'll see several the locations where I've removed the old 811 magnets awaiting delivery of a bulk super magnet order from Hong Kong.  I'll post a video to demonstrate the operation.



OM looking eastOM looking westsupermagnets in package



Images (9)
  • OM looking east
  • OM looking west
  • supermagnets in package
  • uncoupler locations
  • comparing different uncoupler magnets: 6 3mm x 8mm super magnets  - I found 6 gave me about a 1.5"car  spotting area
  • comparing ramps after ballasting 2
  • comparing ramps after ballasting: after hiding the super magnets under ballast
  • delayed action couplers over super magnet: cars with delayed uncoupling "soft" draft gear springs over the hidden magnets
  • non-delay action couplers over super magneted: cars equipped with delayed action defeating  stiff (truck) springs over the hidden magnets
Last edited by Keystoned Ed
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Thanks Ed    I  Appreciate the photos and the information. I now understand why you don't want the delayed uncoupling How ever two more questions why are the rows of magnets at different distance from the rails ? and where did you get the stiffer springs ? I also am working on my coal facilities and power plant.


Last edited by clem k

Jim answered the location issue - it is on a slight curve.  I played with the location of the magnets by moving them around on the drywall screw heads super gluing them in place.  If one wanted a larger magnet field to spot cars over you could add additional pairs to the row.  Two rows of three was a comfortable compromise. Even a single pair of magnets uncoupled the cars,  but the the uncoupling "zone" was only about 1/2". 

Big JIm - You need a magnet field that will pull the glad hands in opposit directions horizontally.  With vertically oriented poles on these magnets you need them in separated pairs to create the side pull to open the knuckles.  

Last edited by Keystoned Ed

For a bulk buy of small super magnets I ran a search on eBay for 3mmx 8mm magnets and purchased a A lot of 150 magnets at a very good price from a dealer in the Far East with a good feedback.  Shipping was free and reasonably fast.

In most yard tracks I locate  uncouplers near the clearance point of the turnout to maximize track capacity.  On industrial sidings magnets are located to position the cut of cars under a tipple or at a loading dock platform.  A couple of my sidings  have more than one industry and they have more than one magnet.

For stiffer draft gear springs I used ones I had laying around in my parts bin - some from old Athearn trucks, others from Atlas or Weaver couplets.  I haven't searched for a new supply of springs but when I do I'll start by looking for steel ones (Kadee' s  aren't steel) close to the dimension of the Kadee ones.  I've found that it doesn't take too much added stiffness to immobilize the Kadee delayed action feature.  

Last edited by Keystoned Ed

Clem, did they have taller magnets at Hobby Lobby?  They just opened a store here in Virginia Beach but I haven't gone yet, this may be a good reason/excuse!

Gargraves/Ross track appears to measure about 12mm (almost 1/2") high from top of rail to bottom of tie.  I'm still using it even though I've removed the middle rail.  I would think a magnet the same height as the tie would work well and not look out of place.

OMG...1/2" is 2 SCALE FEET!!!!!  I can just imagine what that would look like in real life, double what it should be I guess.

I propose us modelers have it right and the real RRs have it wrong .  Just think, more clearance under a train may prevent folks from getting run over or make maintenance easier

Well...I went to Hobby Lobby, they didn't have anything but 12mm diameter magnets so I got a pack.

DON'T use 12mm!!!  They work so good that cars can't roll over them without hesitating whenever the axle passes over them.  I didn't notice any affect on the engine and they most definitely opened the Kadees, but with the hesitation of each car the couplers re-coupled once the car overcame the force of the magnets.

I may still try the 8mm or less diameter.  I also tried double-faced tape (didn't work) and super glue (worked) to hold them in place.

Question, could these magnets interfere with the electronics in the engines?  All that battery-powered stuff I have got me thinking!

 I've used the stock Kadee magnets for 3 rail with a modification. I got the idea from a visit to Cape Cod Northerns layout. Rather than dig up ballasted Gargraves track. I cut the metal plate into strips slightly wider than the magnet. I only use one magnet on each side of the rail. Glue the magnet to the metal then glue that to the tops of the ties. I think I used 3/16 basswood strips which will evenly place the magnets between the center and outside rails. The magnets end up being about rail height. I would say just about every car I own uncouple with this setup. As far as spotting cars using the delayed feature. Probably about 80%. The ones that don't seem to work well and are needed for a particular industry are just swapped out with cars that generally stay in a consist.

 Bob, with your setup with the middle rail removed. I think this would work and could be disguised either with ballast or a walkway across the rails. I gave some thought to practicing on some scrap track. Using the stock Kadee magnet with the cut strip and then placing those small magnets used for activating reed switches to the under side of the metal strip so that they would nestle down between the ties. Might give the magnet a little more force.  I'm not sure of the reasoning behind the Kadee setup with the magnets stacked on top of one another. Not sure if gives more magnetic power or just the fact that 2 are needed because of the higher than scale rails. The metal under the stock magnet seems to be the key.




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