If you can find get it, get "shim brass" -- it's a thin brass sheet
material that comes in several thicknesses and is quite springy. Use the
thinnest stuff. Make wipers T-shaped, so that the T-bar contacts both
wheel treads. The T's shank should be wide enough for a hole to allow
the truck mounting screw to pass through it. File the body bolster down
a bit, so that you put a brass washer between the truck and the bolster.
Solder a fine wire to the washer and pass it up into the caboose
interior. When mounting this, the sequence is body bolster + washer +
wiper + truck. Bend the T-bars until they contact the treads
satisfactorily. Pick ups must be om opposite sides on the two trucks.
Or, get metal frame trucks with metal-axle wqheels, insulated one side.
Use a bolt long enough to pass through the car floor. Use a couple of
nuts so you can lock a washer with attached feed wire to the truck
mounting bolt. Polish all contact surfaces (use Exxact Tool or similar
to burnish the wheel bearings). This way you won't need wipers.
I leave it to you to figure how to hide the internal wiring.
Or, use a small battery, a microswitch, and LEDs.
Better is to get metal trucks and use them with the insulated side of the
wheels on the opposite sides for the two trucks. Do make sure that you have
a plastic frame when doing it this way.
If you really want pickups, spring wire or flat pieces of something like
0.005" thick for the flat stock. I'll leave it to you as to how to bend the
stuff so that it can be mounted on the frame of the truck with some epoxy.
I will say that you don't want to have too much force on the wheels or you
will have troubles with the wheels turning. Also, you will want to have a
pad on the metal for a wiping pad that you can replace when it wears out.
Why isn't there an Ozone Hole at the NORTH Pole?
First off, use metal trucks if you can find them.
Second choice, use axle wipers. The drag is much less than wheel
wipers. The difference in diameter between wheel and axle is a measure
of the mechanical advantage a wheel enjoys attempting to turn an axle
against the drag of the wiper.
Wheel wiper drag can be bad enough to stall the train.
Phosphor bronze makes a better wiper than shim brass 'cause it's
springier. I bought a roll of bronze door weatherstrip to cut up into
wipers. Besides, I haven't found a good source of shim brass in years.
I used to get it from auto body shops, but they stopped using it years
My axle wiper started out as a piece of bronze about 4 scale feet
wide ( to fit inside the 4' 8" gage wheels) and long enough to reach
from axle to axle in the truck. Then do some cutting away to allow the
truck mounting screw to fit. Drill a hole in both the wiper and the
plastic truck to accept a 2-56 machine screw. Use the screw, and a nut
and some flat washers to secure the wiper to the truck, putting it under
tension and pressing it firmly against the axles.
Form the ends of the wiper "up" with pliers to prevent low flying
wipers from snagging on track work.
Hi David, Thanks for your response and the information contained
therein. However, I am still a little confused. I can't grasp the
signal flow through the whell, axel, axel wiper, lighting circuit, and
return to the opposite rail. If I use a metal wheel on both ends of
the axel and a metal axel to make the axle wipes work, haven't I
created a short? Don't I need an isolator in there somewhere? (I've
tested grain of wheat bulbs and LEDs across the tracks and they are
okay, but a metal axel??) And how do I get the return signal back to
the other rail? I'm guessing the reverse of what ever method is
employed on the first truck.
I see your point about axel wipers being superior to wheel
wipers for drag and also ease of installation. However, I can see how
to make wheel wipers work. Hope to hear from you again to straighten
me out on what I'm missing on axel wipers. TIA. Byron
You have to have a metal wheel on one side and a plastic wheel on the
other side of each axel, thus making an electrical connection to just
one rail per axel.
I hope that clears that up.
Wheels set with metal wheels and metal axles have one set of wheel
insulated, usually by use of an insulating medium at the wheel hub. You
can usually see this. The only exception to this is Marklin metal wheels
sets, which are completely uninsulated as Marklin uses a three-rail system.
You orient the metal trucks so that the uninsulated wheels of one truck
are on the right rail, and the uninsulated wheels on the other are on
the left rail. If you want to sue trackpower to light marker
(end-oftrain) lights, it doesn't matter which way round you do it.
The current flow is right rail --> right wheels --> wipers --> lights
--> wipers --> left wheels --> left rail.
Don't I need an isolator in there somewhere? (I've
If you sue LEDs you must use s dropping reisstor, as the LED will blow
if the track current goes above about 1.5 to 3 volts (depebndimng on LED
type). Samne goes for grain-f-wheat - must be 16V capable or else you
need a dropping resistor. OIn bith cases, wire the lights in series.
And how do I get the return signal back to
Good point. Some background. Two rail track always needs the left
wheel insulated from the right wheel to prevent shorts, just as you
said. This point is well enough known to be taken for granted by most
model rails, and in the common case of all plastic wheelsets, it is a
The metal replacement wheelsets sold for two rail trains always have
a plastic bushing between one wheel and the axle. The other wheel, the
"hot" wheel, is common to the metal axle. When assembling the wheelsets
into the truck take care to get the two "hot" wheels on the same side of
the truck, otherwise the wiper will short the track.
lamps have enough resistance to limit the flow of current to
something reasonable when placed across the track. LED's need a
resistor in series with them to do the necessary current limiting. A
"short" circuit is one that has no resistance at all, which allows
enormous currents to flow. For instance an un insulated wheetset would
make such a short.
I would go with incandescent lamp[s]rather than LED's on a first
project because the lamp works properly for either polarity of track
power. LED's only light up with DC applied plus to anode and minus to
cathode. Should the power pack reversing switch be thrown to back the
train up, DC of reverse polarity would be applied to the LED which can
damage them. Typical LED's can only withstand about 6 volts reverse
bias, and a power pack can supply 12 volts, more than enough to destroy
And how do I get the return signal back to
Yes. You put the hot wheels on the first truck on the left hand rail
and the hot wheels of the second truck on the right hand rail. Connect
the lamp[s] between the two trucks.
Other tricks of the trade. Paint the inside of plastic rolling
stock to prevent the lamps from shining thru the roof or making the
entire car glow in the dark. Use light colored or white paint to
improve the brighness of the car lamps. A black plastic interior can
soak up most of the light from the lamps, making them so dim as to be in
visible unless the room lights are dimmed. Locate the lamps on the
ceiling so that they cannot be seen looking in the car windows. Plan
for lamp replacement. I have a lovely old all wood Ambroid caboose from
many years ago. The lamps have burned out and there is no way to change
them short of demolishing the car.