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.
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.
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.
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
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.