Aristo RDC

Swapping out the traction tires: 

First thing I don't like are the rubber traction tires. They rot, cause running problems, and will cause derailments when they come off. On the RDC, which is a long wheelbase loco, they often cause more problems.

They are easy to change out. You need 4 wheels, which will be two of Aristo part number29130 (package of 2 wheels).  These are labelled as "FA1 PLAIN WHEELS W/O GROOVE & TIRES WITH HEADER CARD".

To replace the wheels, you put the RDC on it's back, and remove a side frame. There are 2 small screws. They are in the 2 holes below the springs in this picture. It helps to use a magnetized screwdriver.

Then remove the screw and star washer on one of the traction tire wheels. CAREFUL! The start washer WILL try to get away! If it drops under the truck and you do not see it, it may be sticking to the top of the truck, since the magnetism of the motor can trap it. Just be very careful not to let them get away.

I have a wheel puller that will just fit here. Turns out that the action of putting the puller under the wheel popped it off.  If you do not have a wheel puller, two large flat-bladed screw drivers on either side of the wheel will pop the old wheels off.

I have my finger on the wheel, because, just the action of putting the puller in popped it off.
 

I spun the new wheels on the axle by hand a bit to feel confident they were matching the taper well, knocking off any high spots in the wheel casting. Replace the screw and star washer, and then the sideframe, being careful to try to find the "old" threads in the motor truck, since these are such small screws.

Disassembly:

Remove the car ends first, there are 2 screws on the bottom of each car end, and one very tiny silver screw in the roof. Try very hard to find drivers that fit these screws as closely as possible, the 2 screws underneath are under a lot of tension since they screw into the aluminum chassis. The small one on top can strip the head easily.

Herei's the two cap screws underneath, near the coupler:

Here is the small screw on the roof, it's near the horn:

Once you have the end caps off, let them dangle carefully, there is not much play in the wires. Here's what you see looking into the ends. The cardboard aids the diffusion of the lighting. I decided not to try to reach through this, but to take it apart the rest of the way.
 

Now there are 6 screws along the sides of the chassis, somewhat small. Again these are into metal, so get a good fitting driver. You can see two of them between the square battery boxes and the air tanks, right at the edges of the chassis:

Support the whole thing carefully, since the end caps are loose, and can get scraped up by the chassis and shell. Pull the chassis out a bit and you can get inside.

Try not to whack the lights inside. When you put this back together, try feeding the speaker and smoke unit lights into the hole in the cardboard as you bring the chassis to the shell. This ensures the wires do not knock the lights around.

QSI Install:

You remove one of the square compartments underneath. See the picture above. They both look the same, on has the Aristo socket, the other a socket for the speaker, and another socket. Just loosen the screws, do not remove them.

The easiest way to do this is open the car, and unplug the speaker plug from the circuit board. There are 2 sets of wires going from the chassis to the shelll. The red and black wires are the smoke unit, the two black wires are the speaker.

When you are inside you can remove the MU wires, in this (poor) picture, at the far back left, you see 2 solder pads and black wires, that's one mu cable.

On the right side at the back, behind the bulb, you see two more, that's the other mu cable. I remove them since I don't use them or want to look at them, or have them snag on a switch.

Again, the speaker wires come down from the top, and plug into the board, just to the extreme right in this picture, you can just barely make out the plug with the back wires. Pull this plug from the board.

Now thread this wire and connector down to come out next to the Aristo socket. Button the chassis back together. You can see the wire and plug from the QSI and the speaker wire you threaded through in this picture:

Now use 2 short pieces of wire, like 1/4 watt resistor leads to "jumper" the QSI speaker plug to the 3 pin Aristo speaker plug. 

When reinstalling the compartments, tighten the screws GENTLY, otherwise you will snap the slotted tabs off.  

Visual improvements: 

Pete Eggink has done some neat stuff with his: Click here for Pete's RDC page

Basically he lowered the car, rotated the underbody detail 180 degrees to match the prototype, modified the air tanks.

Improving running:

Several people have reported that swapping the trucks such that the rigid axle is towards the center and the floaing axle is towards the couplers helps. My opinion is that part of the trouble is the traction tires "grabbing", so I would try this AFTER you swap out the traction tires for regular wheels.

If you do this, you will basically have the car running opposite to the directional lighting, so you may have to reverse the motor leads inside. 

From Jeff Cairns: "I sort of went crazy with mine, and ended up making aluminum leaf springs to prevent derailments! The springs go between the chassis and the truck's A-frame, thus enabling the car to rock side-to-side. They can actually handle 4 foot diameter turnouts at full throttle now!"

Misc Data:

The motor in the RDC-1 is a Mabuchi 385 PH (same as dash 9)