I went through most of my trains last fall and put on Kadee couplers
but I still have some problems with cars that just won't stay
coupled. It is so frustrating! A train can run and run and run one
day and the next day it won't. Any hints or suggestions about what to
If you helped me with my ballast question I want to say thanks again
for that. However, I have put off laying down any ballast until I get
this coupler problem resolved.
Have you used the Kadee #205 (or the new #206) coupler height
adjusting fixture to check that all your couplers are at the correct
height, and that the trip pins are also properly adjusted?
You also need to check your track for dips/rises and correct any that
The most common cause of random uncoupling is the combination of one
high and one low coupler going over uneven track.
A rise will cause the high coupler to lift out of the low one, and a
dip will cause the low one to drop out from the high one.
I'll assume you have a smooth roadbed (of wood or plywood, etc), and
have glued cork or similar down as the ballast former. Then the usual
reason for dipsy doodles in the track is track pins or nails driven in
with a hammer and squishing down on the ties. _Tap_ the nails in, and
stop just as the nail head touches the ties. If anything, let the track
float a bit. The nails are just there to hold it from sliding sideways
(until you've ballasted, after which you should pull out all the nails.)
So, if necessary, pull out pins or nails, drill holes in adjacent ties,
and insert new pins.
If there are dipsy doodles caused by evennesses in the road bed, you
insert shims under the ties. Use varying thicknesses of card and heavy
paper. Sight along the track to detect dipsy doodles and waviness. A 9"
level is a good tool to check level across the track.
Evening out the track can be a real ratselfrass problem! First you need to
start iwth smooth subroadbed. Joints at the ends of plywood pieces need to
be smooth with no angle between the pieces. This is the usual start of any
problems with trackwork as the track will make a vertiical bend at the
joint that will be difficult to get rid of as all you do is pread out but
the problem is still there.
Next is that the track can't be mailed down so hard that it dips at the
Basically you have to go through all of the track checking for little dips
and peaks and figure out how to adjust the roadbed to make the track nice
and smooth. Look at pictures of any of hte large layouts for what your
track should loook like for level and curves. The smoother you get the
trackwork the less problems you will have with it.
I lay my track by the old handlaid method and do that on spline roadbed wo
that there are no sudden changes in the track. This is the superior method
still when done right as the roadbed sets the grades and curves of the track
in one continous length.
rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net
I think this is one of my problems. Not all the couplers are exactly
the same height. But I don't know how to adjust that. Some of the
couplers are attached to the cars themselves and others are on the
Do not mix "body mount" and "truck mounted" couplers. Ever!
A) To adjust coupler height:
First, buy a Kadee coupler height gauge, and make a test track. Mount a
length of track on a 1x3" board, and fasten the coupler height gauge to
Second, buy a coupler pin pliers - this is a pliers with one jaw
machined like a U, and the other machine to fit into the U. You adjust
the trip pin by squeezing it _gently_. To raise the pin, put the pin so
it fits inside the U, to lower it put the U inside the pin (easier to do
Third, inspect and test all cars. Couplers must not droop, must be at
the correct height (within 1mm or 1/32nd inch or _less_).
Fourth, prepare a number of couplers for mounting, as described on the
A1) To lower coupler height: one or both of the following
--- glue a cut-to-size plastic pad onto the car frame where the coupler
will be mounted. Those plastic closures on bread bags etc are just right
for this - they come in two or three thicknesses. Then glue the coupler
to the pad. Make sure the coupler is centred left to right at the car end.
--- File down the bolster. Caution: the trucks and wheels must not rub
against the bottom of the car.
A2) To raise coupler height: add one or more washers between truck and
bolster. Kadee makes two thicknesses - but a pack or two of each.
--- It's sometimes possible to cut away the molded in coupler mounting
box, file a flat area on the frame, and mount the coupler at the correct
height 9with pa plastic pad if nececsaary).
A3) To body mount couplers:
--- cut couplers off trucks, or replace trucks.
--- prepare a flat area for coupler mounting.
--- test car against coupler gauge. If the car passes over the knuckle
but stops at the pin projecting above the coupler, then the body is at
the correct height. If necessary, adjust hieght up or down as decsribed
--- glue coupler onto car.
--- If desired, drill through the screw hole into the car body, and snug
down a screw. Beware of over tightening.
Final tip: replace those plastic wheels with metal ones.
As David says, check couplers.
Kadee has a 'coupler height gauge' which is very handy. It can be used
as a 'Track Gauge', set it on he track, roll a car up to it and you can
see it the coupler is high/low, there is a 'shelf' to check that the
coupler operating pin [masquerading as the 'air hose'] is not too low.
The 'coupler height' does NOT need to be exact, but things work better
if there is little or no variation.
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