unwanted uncoupling using Kadee couplers - magnets

I have encounterd a frustrating problem. I am in the process of
building a small shunting lay out using Kadee's. I have converted a
small batch of mainly Bachmann goods wagons to start me off. Last
weekend I have installed a couple of under-the-track magnets.
Everything works fine apart from one thing. When I go really slow over
a magnet, the last wagon in a rake uncouples and gets left behind.
After careful observation I have concluded that at this low speed, this
last wagon is pulled slightly forward by the magnet (or actually it is
the axle that is attracted by the magment) which releases the tension
on the couplers and the whole thing uncouples. If you go faster, the
magnetic pull is slower than the train so everything is ok. The other
connections in the train are not affected because the magnetic force is
only strong enough to pull one single wagon forward, hence only the
last wagon is affected. This, at least, is my theory. Have you
encountered similar problems? Any solutions? Thanks in advance.
Reply to
Jim Northolland
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"Jim Northolland" wrote
Common problem with Kadees, which can be reduced by fitting wheelsets with brass or plastic axles. P2K produce some wonderful wheelsets - metal wheels with plastic axles which I've used quite successfully.
John.
Reply to
John Turner
Or the best and most realistic solution, uncouple by hand using any of various tools that you can make or purchase. Then, like the prototype, you're limited to where and when you uncouple.
-- Cheers
Roger T.
Home of the Great Eastern Railway
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Reply to
Roger T.
In message , John Turner writes
I've got some wonderful wheelsets with plastic axles courtesy of Wm K Walthers. Unfortunately, the axles are not straight; result: random derailment on the points.
Reply to
Jane Sullivan
No, if the vehicle is not quite in the right spot you can get a real "Road Runner" effect as the vehicle suddenly wants to become centred over the electromagnet. The look is woeful ;-) The problem will always occur to some degree if you use steel axles or rims.
Reply to
Kevin Martin
"Jane Sullivan" wrote
That's why I recommended the P2K wheelsets. Experience has suggested around 99% run true - Bachmann (and Walthers) take note!
I believe the P2K sets are made in the factory which produces Hornby's models, which maybe explains why Hornby's wagon & coach wheels are true.
John.
Reply to
John Turner
slow
behind.
actually
prototype,
Hmmm, I haven't see any 75t breakdown cranes [1] being used to uncouple before....
[1] the nearest equivalent to a bloody great hand with wire hook descending onto the stock!
Reply to
:::Jerry::::
actually
real
centred
It can only move in the coupling slack surely, and one could always energise the magnet before the train moves over the section of track, or am I missing something about how kadee's work?
Reply to
:::Jerry::::
If you don't want the expense of electromagnets, hinge the permanent ones. A friend of mine does that and raises the magnet for uncoupling with a knob on the fascia.
Reply to
Larry Blanchard
I was going to say the same. Electromagnets for Kadee/Microtrains is expensive/awkward because they need both ends of the field under the track.
I've used hinged and sliding magnets for Microtrains in N (my small US outline collection); works very well. The O-gauge magnets are more than strong enough to work through a thin track bed (cardboard) and the plastic track base of Peco N.
- Nigel
Reply to
Nigel Cliffe
The problem with magnets is: You never have enough until you have too many.
Absolute fail-safe solution guaranteed to work every time: Throw the magnets in the dustbin and cut the trip pins off the couplers.
Then, use a small bamboo skewer that you can buy at the food-market for making fondue and such. I use the ones that are about 4mm diameter and about 100mm long. They work amazingly well and allow you to uncouple anywhere without restriction, same as the prototype. The ugly magnets are gone, there is no mucking about trying to engineer some lame hinge that you have to mess around with every time you want to uncouple, you will never have an accidental or unwanted uncoupling account of an inconvenient magnet location. There is no burden of buying expensive electromagnets, each of which costs as much as several new wagons, and no screwing around trying to install them such that they work reliably. You DO NOT need to change your wheelsets because now there are no magnets to attract them. The specious argument about there not being any such thing as a 40-foot uncoupling pole is nothing but silliness. It's true, there isn't, but the prototype do not use between-the-track magnets and 100mm diameter trip pins either. Nor do they use Kadee couplers. So think about it, Do you want to have a good time operating your trains and shunting cars, or do you want to spend your time trying to solve mechanical engineering problems?
Reply to
66class
As stated in earlier posts replace wheels with non magnetic types. I prefer non magnetic metal axles over plastic ones. I have uncoupled Kadee's magnetically for over 30 years without the problems stated above because my couplers are installed according to the instructions. Kadee have solved the mechanical engineering for us. I only install the hinged under track magnets on mainlines, for sidings fixed under track magnets do the job. With short 4 wheel wagons I permanently couple them in groups of 2 or more by cutting the pin off one coupler. I also use a wagon weight formula to improve Kadee coupler performance. Do the above and you will get a much better system of uncoupling than over scale pole and digit method which is useless in wide yards next to main line running lines. The last thing you want is shirt sleeves knocking trains over, or over scale shunters blocking the view of the layout for other train operators. If you are fitting new couplers to your models I recommend the Kadee #78. See my web page on how to modify these for wagons with buffers.
Terry Flynn
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HO wagon weight and locomotive tractive effort estimates
DC control circuit diagrams
HO scale track and wheel standards
Any scale track standard and wheel spread sheet
Reply to
NSWGR
"Jane Sullivan" wrote
So does mine, but fortunately they give the option of turning off the spam filter.
For the amount of spam I receive it's easier to delete the spam messages than go looking for mis-filtered messages.
John.
Reply to
John Turner

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