DCCconcepts Pty Ltd, 3/13 Lionel St., Naval Base WA 6165 Australia. * www.dccconcepts.com * +61 8 9437 2470 * [email protected]
Installing a decoder into non-DCC ready locomotives.
This can be much easier than you might imagine. You will
need only a few simple tools and it is a job that every
modeller can manage quite easily if you just take your
time and follow a few simple rules. Here’s how.
Do the same checking as on page 1.
As with a new DCC ready locomotive, give the locomotive
a good test run, adjust as needed, lubricate/clean and
check pickups. Make sure it runs well… before you take
the next steps.
Remove the wires from the motor brushes and check.
We need to have 100% separation between track power
and the motor brushes. After removing those wires from
the motor brushes, place the locomotive and its tender (if
it has one) onto a length of newly cleaned track.
Set your meter to Ω “ohms”.
Place one probe on the left rail and then touch the other
probe to each of the motor brushes in turn. There should
be NO reaction. Now move the probe from the left to the
right rail and touch each of the motor brushes again. As
previously, there should be NO reaction.
If you had no reaction, move to the next step. If not,
then we will need to do a wee bit more work first!
If there WAS a reaction, we really DO need to isolate that
motor brush before continuing or the decoder will be
damaged.
Again you will find the Web helpful. Ask us, Search with
google or ask on a forum. There WILL be someone who
can help you with good advice and maybe even photo’s!
Possibility #1:
If it’s an open frame motor with a V
shaped spring holding brushes mounted into an insulated
strip on the motor (like the Triang/Hornby XO4 motor),
then you will just need to isolate the brushes from the
spring by adding heat-shrink or a tube of insulation
stripped from some wire.
Possibility #2:
It is fortunately quite rare, but if it is an
open frame motor and one brush is set in to/not insulated
from the metal body of the motor itself, then you will have
to isolate the WHOLE MOTOR from the loco frame.
(examples, US Pittman type motors or some of the earlier
designs of Hornby-Dublo and Wrenn locomotives which
use the chassis as part of the motor frame).
Possibility #3:
Motors that have one motor brush
grounded to the frame by a metal clip or a screw that
penetrates into the frame. You will need to remove or cut
the clip. If it’s a screw, either use a shorter screw OR drill
out the screw hole and insert a plug of plastic, then drive
the screw into the plastic plug. (examples are Many Horn-
by tender or motor bogie drives, Lima, Rivarossi, some
Mehano, some earlier low end US diesels).
Possibility #4:
Pancake motors with a metal or PCB type
faceplate such as Fleischmann. If it’s a metal plate, then
the plate needs isolating from the motor frame. If it’s a
PCB plate, then the tracks need cutting to isolate the mo-
tor brush from the frame. Fleischmann also do make
some replacement “DCC motor plates” for this kind of
pancake motor if you aren’t confident doing modifications.
Possibility #5:
Motors that are semi-embedded into a
cast chassis - this is very common with earlier US loco
brands such as Athearn. The top brush has a long metal
clip that joins the motor top to a metal bracket on top of
each truck tower, the lower brush contacts the chassis
via a clip. Throw away the top clip. Remove the motor,
remove the bottom clip and insulate the area below the
motor with thin plastic OR (a top tip) a couple of coats of
clear finger-nail varnish. Solder one wire directly to the
bottom brush clip, the other to the top brush retaining clip.
Keep the lower wire really flat relative to the motor.
Possibility #6:
The split chassis: Commonly used by
Mainline, earlier Bachmann. The motor is encapsulated
between the two chassis halves. The halves are insulated
from each other and the brushes of the motor make con-
tact with each chassis half via a spring clip on the brush.
Disassemble the chassis parts and carefully remove
these clips as cleanly as possible. Grind out the area
where they made contact with a Dremel or similar. Coat
the area with some clear nail polish, leaving it lots of time
to dry. Solder pre-tinned wires to each brush, keeping the
join tidy and flat (minimum solder). Reassemble but be
careful about where the wires run—be sure you do not
get them caught between the chassis and motor etc. or
the insulation may be damaged, causing a short.
There are many things on the DCCconcepts website
that make installation easier...
