I’m not satisfied with permanent magnets for uncoupling. Too often they don’t work, are not consistent on different makes of couplers or cars uncouple while passing slowly over the magnet locations. I went online and found one made by Kadee, HON3 #708. Has any one ever tried to use or modify this Electric Uncoupler Kit or scratch build your own electric uncoupler?
KADEE/MTL used to make a electro-magnetic uncoupler, but I don't see one listed on their website now. It worked very well and all you had to do was push the button to induce the magnetic field that uncoupled the couplers. No false uncoupling when the button was not pushed. The only problems were that you could NOT hold the button down for more than a second or two or else the electro-magnet would burn out just like a twin-coil switch machine. And that the electro-magnet took some POWER to make it work, best to run the electro-magnetic uncoupler off it's own dedicated power supply. There have been write ups and articles in MODEL RAILROADER(I'm thinking) on how to build your own electro-magnetic uncouplers. I've built a few and they worked very well. I plan to use mostly the electro-magnetic type uncoupler when I finish rebuilding the INDIANA RAILWAY.
Some Model Railroader articles of "recent" vintage on building your own electromagnetic uncouplers: An N gauge electromagnetic uncoupler - adaptable to HO Model Railroader, February 1979 page 92 The ultimate uncoupler Model Railroader, January 2000 page 109 I can tell you the one from 1979 seems pretty simple to construct. I read the article when the magazine was new but did not build any. Attention span of a teenager (me at the time) being what it is and all.... I have been considering making some of these for my current HO scale railroad. Just need to find some old CRT TVs on the roadside for the copper wire for the windings.
I build uncoupling ramps based on one of those articles (I believe, I haven't looked at the original article in some time). Mine use pieces of shelf standard as the steel core. They work very well. I have done as suggested above and use a separate power supply. Also I have upped the windings to 380 and the voltage to 25 volts. My dad made a winder to chuck in the drill press which includes a counter. Makes winding them pretty easy. There is one caveat. The couplers need to be in top operating condition. No burrs and well graphited. The electro-magnet is so strong that I have a Life-Like NE caboose that had a steel weight and when over an activated uncoupler would rock back and forth about an inch.
We're talking here about an electro magnet uncoupler mounted under the track, the $450 offering from Kato is a DCC operated coupler in the tender of the loco. Which is either too expensive or impractical, you'd only be able to uncouple the engine from the car behind it, because I still haven't heard of anyone who's bought one. I can't comment on the subject under discussion because I uncouple manually, it never fails, you can uncouple anywhere and it's the way we do it on the prototype.
Michael I read the article. The problem is you still have to put the magnetic plates above the cross ties. Perhaps I'm asking too much, but I'd like a more elegant solution where no part of the electro magnet is seen. I'm not electrician, but I'm wondering if someone reading could figure out how to build an electro magnet that is focused (magnetic field is strongest) where the trip pins would be. I'll keep looking.
Mark (Spookshow) got one of the Kobo's. It is pretty cool and worked reasonably well. It was operated by a Memory Wire spring. Current applied to the spring makes it change shape and open the coupler. He had some posts about it here a month or two ago.
On the electro-magnetic uncoupler I make, the whole thing goes under the track. I cut a slot in the subroadbed/roadbed and position the magnet so it is directly under the track and centered under the rails. I then cut a piece of sheet acetate to glue to the roadbed and cover the uncoupler. This keeps moisture from ballasting from getting to the uncoupler. Once ballasted the uncoupler is unseen. In fact, I am going to place a railroad sign with a "U" on it at the center of the uncoupler so I know where to position the cars.
