I have installed some Kadee under track uncoupler magents.They work fine when uncoupling and then pushing the car in the siding.The problem occurs as I pull the car out of the siding across the magent using consent speed the car uncouples. ANY suggestions would be appreciated as how I can solve this problem. Thanks for looking at this topic and your comments.
Tomas in Durango
Tomas:
Your problem is related “slack” in the coupling between cars as they pass over the magnet. I’ll bet that you don’t have the problem if you pull across the magnet rapidly. In order to stay coupled while passing over a magnet the couplers must be in tight contact. One cause of your problem may be some hesitation in the engine as it moves slowly thus allowing momentary slack and subsequent uncoupling. A good engine tuneup may result in smoother low speed running and help with your problem. You might want to check the weight of your cars. Cars that are too light allow for slack to develop easier. I had a problem with one particular magnet on my layout and finally found that it was on a stretch of track that was not level. When the train would approach from one direction the cars would bunch up a very small amount and I would get random uncoupling. WHen going in the other direction, there was no problem since gravity was keeping slack out of the string. I hope this helps. I’m sure that others will have some tips also.
Joe
another option that is available, though slightly counter productive, is to fit a little coil spring over one of the pinpoint bearings .it acts as a slight brake. either microtrains or kd actually produce springs for this purpose. it probably came about because their wheels turn so freely that on any grade, cars would just roll and not stay where put.
[#ditto]
All it needs is just an instant of slack. I use a Bachmann magnetic uncoupler on my passing siding. First I secured it to the bottom of the track section like the instructions say to. With plastic wheelsets on the cars, I had no problem. However, when I changed over to metal wheelsets, Whoa Nelly!! There wasn’t any problem with the track, it was the wheelsets causing the problem. With metal wheelsets, you can gently blow on the end of a car and it will start rolling. The solution that work for me was to pull the magnet off the bottom of the track section and just lay it on the surface beneath the track. It’s only a very slight difference in distance, but it made all the difference in the world. Now the cars won’t uncouple unless I stop the train, back it up just slightly so all the tension goes out of the coupling, then pull slowly forward. With the magnet being farther away from the track, the couplers open just a tiny bit, but that’s just enough for them to slip apart.
My guess is that the magnets may be too strong, or mounted too close to the track level. Try lowering them a bit, if you can do that. If you are getting really great uncoupling performance, then you have lots of room to work with. Adjust the height until you barely get the desired intentional uncoupling you want. That should reduce the unintentional uncoupling.
Make sure your wheel sets do not have steel axles. Also the cars weights may be steel and with free rolling trucks the magents will move the whole car.
The club worked on this exact problem Thursday night. The “KADEE CREW” found that the tracks had to be 100% level or the cars rolled back together after uncoupling and that if you came oot of the siding at less than 6 SMPH (we have QSI with scale read out) YOu would have the uncoupling problem.
The result was that the best way to stop this was an electromagnet instead of a fixed magnet. Problem was, have you ever seen the SIZE of the Kadee elctromagnet, and also the cost per siding. We tried adjusting the trip pins, NO GOOD, Tried lowering the magnet OK but caused problems with the EZ-MATE type couplers, that is why we are taking all those out and going 100% Kadee.
I am now looking for a MINI electro magent to try. I am more worried about the yards than the sidings. The “CREW” came up with a count of 76 uncoupling locations on the layout so COST PER is a factor.
PS Good Question!!!
Some one has already mentioned steel axles. Also check your cars for steel plate weights. Any steel in a car will try to move towards the magnet. Many manufacturers still put steel plates in the bottom of their models. The first thing I do with any model is remove the steel and replace with lead weights.