Bachmann Rail Truck

How to improve the drive train.

The rail truck is a fine model, but many run noisy or erratically out of the box.

The problem is the bracket that holds the worm gear in the drive train is often not completely tight and this allows the mesh of the gears to be erratic, often resulting in premature wear or stripping. The screws are too long, they are about 0.195" in length, and need to be no longer than 0.150".

The supplied screws bottom out in the holes, so the keeper (00L06) from holding the brass bearing tightly.

Procedure: (courtesy Dave Goodson)

1) Remove all stake side boards from bed.

2) Remove box cover in bed.

3) Open one hood side. Flex radiator forward slightly at radiator cap, remove hood.

Open other hood and repeat.

4) Remove front screw holding down box into bed. Not the circuit board screw.

5) Turn unit over. Remove 2 rear cab screws. These are located in front crossmember of bed support.

6) Lift cab at rear, allowing box to flex up slightly. Pull cab back and undog cowl from firewall. Lift cab off and set aside. (You can access rear screw of box. This requires removal of switch, flexing of wires, and may not be something you want to do).

7) Remove 2 small screws holding floorboard down, one each side of gearshift lever. Lift floor and remove. If difficulty is experienced, lift seat straight up, remove on screw in bottom of seatbox and remove seatbox.

8) Remove 2 screws holding black support bracket to gearbox just forward of front u-joint assembly.

9) These are the problem screws. They are approximately .195” long, from under head to end of threads. They need to be less than .150”, which can vary with how deep the holes are on your unit. Cut off about .050” and file flat, or obtain new screws of proper length, and re-install. Make certain black support bracket is fully seated by pressing down and looking for air gap under screwhead. Washers should not be used as this will hold the floor up, preventing it from laying flat against frame.

10) Re-assemble in reverse order after lubricating gearbox.

As an addendum:

The screws provided with the snowplow are exactly the correct length.

Once you have the model open (remove stakes, box cover, hood, and the screw that holds the bed, 2 screws underneath that hold the cab, and 2 screws that hold the floorboard) look at the black bracket just in front of the u joint. The screws that hold this bracket are too long and bottom in the hole before they tighten the bracket tightly.

Some people have found they can just tighten the screws down really hard, but the best thing to do is remove about .05" from the screws and put them back in. Don't put washers under the screw heads, you will have a clearance issue with the floor when reassembled.

DCC installation:

DANGER! WARNING! Do NOT believe the Bachmann wiring diagram, not all rail trucks are are wired the same!

The basic instructions have you remove 3 wires from a terminal block. The wires in 1 and 2 are supposedly the motor leads, and the wire in 3 is the ground for the common wired LEDs.

Then the terminals 1 & 2 are used for track pickup connections. 

On a recent model, the motor leads (directly from the motor) were not soldered as per the diagram. This installation, by George Schreyer, worked as per the drawing.

On an early model, the motor leads were soldered into the M+ and M- pads, and this did NOT work, apparently there was still some internal connection between one track pickup and one motor lead. The Zimo decoder used just went to full speed at any speed step. Luckily it did not melt down.

Once the motor leads were removed from the circuit board and directly wired to the decoder, all was well. The leds were still powered from the track, and we left it that way.

My suggestion is to do the same thing, do not trust the Bachmann wiring. We encountered the same "internal" connection on another Bachmann loco, the consolidation.

The decoder used, the Zimo 642 works great and is a HO decoder and we used the Galloping Goose sound file, which is a free download.

There's more to do to set the file to have the horn on the F2 key.

More tips:

Read George Schreyer's excellent page: http://www.girr.org/girr/tips/tips8/bachmann_railtruck_tips.html

Bachmann 10 Wheeler - Anniversary - "Annie"

Page under construction

Quick links to major topics on this page:

• General comments
• Disassembly
• DCC installation
  
• Schematic

General comments

A nice looking 4-6-0. Pretty close to the popular Baldwin locomotive. I'm modeling Santa Fe, so I had to buy an undecorated one.Mine came in the red Spectrum box.

The 10th Anniversary version was shown in 1999, in a separate "Spectrum" catalog. They were mentioned in the 2001 catalog, but the pictures in the catalog show plastic side rods.

What I bought was in a red box with "Spectrum" on it. 

The "Annie" (because Bachmann calls it their "Anniversary" edition of their popular "Big Hauler" has 2 different versions of valve gear. Certain road names and the undecorated one have the more complex Walschaerts valve gear, some of the others have the more simple Stephenson valve gear. I like as much "monkey motion" as I can get.

I've found some pictures of an ATSF loco close in configuration, the 533, which has the same cab window configuration. The bell is in a different place, but the overall look is close.

Distinguishing features:

The Anniversary Edition can be either the version 5 or the version 6 chassis...there were some Costco/Sam's that were contracted to be a price point (we need to talk) and at one point Kader dragged out the old molds to satisfy that.

In the photo, see the small rivets on the smokebox? Not pie plates? Anniversary.

Metal rods with oil caps. Anniversary.

Crosshead guides with oilers.

Smokebox support rods screwed to pilot beam.

Metal piping (and cooling coil on outside of air tank).

Electrical conduit and junction box.

All specific to "Anniversary" design.

Notice the top of the steam dome is gone, with whistle and pop valves.

Disassembly

The loco has 9 screws to take off the boiler.

• 2 at the back of the cab. There are 4 screws at the back of the cab underneath, pull the 2 inner ones. (the 2 outer screws go to the air tanks).
• 4 underneath, around the air tanks. 
• 2 on the sides of the boiler, just under the running boards, directly in line with the boiler band just ahead of the steam dome (with the whistle).
• 1 more underneath, right in the center, swing the leading truck to the side, it's long.

When you get all the screws removed, the air tanks on each side pull straight out. There is also an "air line" made from wire that goes between the two tanks, with a little "bow" in it to clear the boiler.

Be sure to remove the ends of the "brass" handrails that go into the boiler. Just pull them straight out, don't remove the bottoms.The tender has screws in the 4 corners.

Remove the diagonal braces from the smokebox to the pilot deck by prying the smokebox ends out. Then remove the pilot deck with 2 screws.

Now the boiler should be free to move.

Everything else comes apart pretty easily.

Note on loose drivers: The drivers are in 2 pieces, there is kind of a "hubcap" over the rest of the driver, and you pop it off to reveal the rest of the driver, and the securing screw in the center. If you get loosening, use Loctite 222 on the thread.

DCC installation

The smokebox front just pops out, held in by 2 tabs in the boiler. Ease the bottom one a bit and carefully rock the front out. Now you can cut off the switch wires or rewire the switches under the front cover. This is the easiest way to do a DCC installation.

There are two switches, a "direction" switch and a "smoke" switch.

The "direction" switch on the smokebox has 4 wires coming into it. Remove all 4 from the switch. Now you need to find which two of them are the track pickukps. On the locos I have worked on, there was no consistency of heavy vs. light wires or red vs. black.

Use a ohmmeter to find the left side (fireman's) track pickup and the right side (engineer's) track pickup. Hook these up to your decoder. Then connect the other 2 leads to the motor leads from the decoder.

Test the loco. If it runs backwards, swap the two leads to the motor.

The easy way to wire the rear headlight is to leave it connected to the motor. This is wired down inside the loco. The advantage of this is it's easy, the disadvantage is that the rear headlight will only come on when the motor is moving a certain speed and above. It will only come on in reverse and cannot be controlled otherwise.

I also noticed it looked like there was no dropping resistor on the rear headlight, at least in the tender. We checked on our last install and did not find the resistor in the tender either, but it really appears to be the same golden led as the headlight. I figure there is a dropping resistor somewhere in that pair of wires in the loco. It's connected to the motor internally, so if you leave it alone, it will only go on in reverse when the loco is moving as mentioned earlier.

The headlight is a led with a 1k resistor in series. It is wired to the smoke unit switch. Remove the wires from the switch and wire to your decoder. I added a 600 ohm resistor to this, since I use a higher than normal track voltage, so I measured the current at a normal dc level, and figured 100 ma was about right, so the extra resistor kept the current in bounds.

Here's a schematic of the loco:

http://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=66_69_148&products_id=4080

Aristo RDC-1

This is a nice looking model, but many people have issues with them, so read the suggestions below. Many people complain about derailing.

This is a long model, and has a lot of overhang, so I also use this as a "clearance" test, both on the outside and inside of curves.

Notice that the prototype "A" end is the end the radiator nacelle is closer to.

Note: As of August, 2010, the longstanding RDC-1 was joined with a new RDC-3, which has completely different internal wiring, and an interior!

Notice that Ted has a vignette on the RDC-1, CLICK HERE.

Swapping out the traction tires: 

In general I don't like are the rubber traction tires. They rot, need replacement, and reduce power pickup. In the case of the RDC they cause operational problems.

What happens is the wheel with the traction tire pulls the loco more than the wheel without, and the wheels tend to actually climb off the rails in curves. Normally you don't see this in most locos, but the extra length, and sensitivity to cross level really shows up in the RDC. Also, since they normally run alone, there's really no need for a traction tire.

So my advice is swap them out for "solid" wheels.

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. This is a lot better way to do it as opposed to levering 2 screwdrivers between the motor block and the wheel.

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.

 Adding Kadee couplers:

According to the Kadee site, the 901, 907 and 789 are recommended. There is no further information or detailed installation information.

The 901 is a centerset coupler, and the 907 is that coupler in the 831 coupler box. These are the "new type" couplers. The 789 is a "original style" centerset coupler in the 831 coupler box.

Removing the stock couplers is easy, remove one screw for the long "centering spring", then remove the other screw that actually holds the coupler:

For the coupler, you need to drill a hole slightly offset in the Kadee,I "painted" the hole red to avoid confusion. Use a drill the diameter of the original screw, about 0.1"

The coupler height comes out perfect: (well maybe a touch low, maybe I'll go back in and trim a bit from the post)

Disassembly: (differences between RDC-1 and -3 noted)

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 of an RDC-1. 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. The RDC-3 has an interior. This is the time to "untie" the knot of wires in an RDC-3.

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: (again an RDC-1)

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 DCC Install: (RDC-1)

To get to the Aristo socket, you remove the engine compartment box nearest the 3 slide switches. You don't need to remove the screws fully, the screws are in slots, not holes. The engine compartment boxes are the larger two underneath. There's nothing under the smaller 2 boxes, which look like battery boxes). Just loosen the screws, do not remove them.

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

If you need to access the speaker connector, it is under the other engine compartment box. you will see 2 connectors, the 3 pin one is the standard connector for the speaker used by Aristo on other locomotives, only the outside 2 pins are used. The 2 pin connector is paralleled with the motors.

So there are 2 ways to get the speaker wires down to the decoder.

• One way is to make a jumper from the compartment that was intended to house the sound unit, over to the other compartment that has the socket for the decoder.
• The other way is to unplug the speaker from the main board inside, and fish it down into the decoder area.

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. 

QSI Sound file Tuning:

Notes on the prototype:

The RDC had 2 Detroit diesel motors, each powering only the outboard axle. The transmission was by Allision. There was a "TwinDisc" torque converter with lockup. Apparently the lockup was at about 55 mph. It's not clear yet, but it seems that by alternately pressurizing the 2 torque converters, this gave the equivalence of 2 gears, and the torque converters allowed the smooth transition in speed and obviated the need for a clutch. (The torque converters essentially were variable ratio transmissions like the old Buick "Dynaflow" transmission".

More as I research further.

Matching the sound file to the prototype:

I'm experimenting with a new sound file from QSI, that simulates the automatic transmission, the prototype had a torque converter.

First, the momentum and the notching CV's have no measurable effect on when it shifts gears.

As usual, I have the jerky/shaky startup and had to play with some parameters.

I followed the QSI tuning regimen by turning off BEMF (CV 56.4 = 0), then change start voltage (CV 2) so the loco starts moving at SS 8, and reduce it until it just stops. Then turn BRMF back on (CV 56.4 = 1)

My start speed came out at 8.

I set the pid's as on the QSI section, 10, 2, 5 for all 4 ranges, but this did not help much.

I raised the minimum BEMF (CV 56.5) to 20, although there was not much difference above 12.

The "upshifts" occurred at speed steps 11, 21, and 31

 The "downshifts" occurred at speed steps 30, 20, and 10

the horn and the bell sound nice

The prime mover volume is way too low, I raised the master volume to 127 and still too low, the air pumps and the fans can drown it out.

Visual improvements: 

Pete Eggink has done some neat stuff with his:

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

I copied the below from the internet wayback machine. Pete, I'd like permission to post this, but we cannot find you!

The first time I saw the Aristocraft RDC was at East Coast Large Scale Show in Somerset NJ a few years ago.  I liked its long, lean look and and accurately shaped ends and roof blister.  It took a couple years before it got to market, and I was waiting for the Reading paint scheme, but finally I gave up waiting and got a Long Island car as a Christmas present.  It didn't take too long before I took it apart to make a few modifications. 1.  First I disassembled the car and removed and discarded all interior lighting and cardboard baffles. Since it would be converted to battery power, I also removed the circuit board. I marked, removed, and cut the ends of the steel weight, so that the remaining piece was 16 3/4 inches long.

The area where the truck swivels was cut out and moved up about 5 mm by adding styrene spacers and securing with nuts and bolts.  Also a new access hole was cut for the wires because the trucks were turned 180 degrees to shorten the car's rigid wheelbase from 26 down to 17 inches.

2.  I wanted to lower the body about 5 mm because the car seems to ride too high on the trucks.  I did this by raising the area where the trucks meet the body.  I cut 3 1/4 inch ovals in the aluminum frame around the truck mounts.  I made a spacer out of 2 pieces of .080 styrene, 3 5/8 by 5 inch, with a 3-inch-diameter round hole in the center. I sandwiched the spacers between the metal parts and bolted them all together with 8 bolts (I used the small nuts and bolts that come with Kadee 820 couplers).  I remounted the trucks but had to shave a little plastic here and there, on the trucks and the spacers, to enable them to swivel freely. 3.  To lengthen the run time on batteries, I de-motored one of the trucks.  To do this, I disassembled the power brick, removed the motor and the gear-axle side of the universal joint, and removed the gear inside the case on the swiveled axle.  Even with only one truck powered, this car can pull a decent size train! 4.  In order to improved the tracking with this long car, I reversed the orientation of the trucks, so that the swiveled axles would be toward the ends.  I also had to open a new access hole for the wiring.  5.  Unfortunately, the underbody details on this model are a mirror image of the way they are on the prototype  (the motor housings should be on the right as you look at the car from the side).  Since I had already removed the circuit board, I didn't have to worry about the underbody switch panel.  I flipped over the steel weight, so its holes would line up with the mounting screws at the reversed locations.  Then I lined up the details, marked the holes, drilled, and reiinstalled in their corrected positions. 6.  The air tanks look far too low, so I shortened them by a half inch with wirecutters and a file and remounted them.  Because of the cuts, the original screw wouldn't work, so I improvised.

7.  Next I rewired the unit for battery power.  I installed 18 volts' worth of 3-amp-hour NiMH batteries and a 75 mHz Onboard receiver.  I also installed a charging jack and on/off switch on one of the underbody motor assemblies.  See the battery power page for more details on circuitry. 8.  Next I linked the transmitter and receiver and got 'er running.  This was great fun!!

9.  Next I made end walls, because the cardboard was removed in Step 1. I cut and fit .040 styrene walls between the cab and body at each end, and attached to the end pieces using pieces of styrene.  The color of the cab side of these end walls should be silver. 10.  I Installed a Kadee coupler on the front and shortened the Aristo coupler on the other end. 11.  This was a Long Island car I wanted to change to Reading.  I painted the orange end doors silver. Then I removed the paint on the aluminum sides with a single-edged razor blade.  For side-panel lettering I used 1/4 inch stick-on lettering and colored it with Polly-S black paint.  I made Reading Diamond Logos for the ends by shrinking an image on a copier using adhesive paper, and for the yellow I used a highlighter pen. 12. I masked the roof blister and painted the radiator screens flat black. 13. Then finally I reassembled the car; roof blister to body, body to frame, then ends to frame and body. 14.  After I ran this car for a while, I finally got around to installing LED headlights.  I removed the front cab and replaced the headlights with bright yellow LED's (All Electronics #LED-72).  I installed a 2-cell AA baterry holder to the back of the cab wall, wired a 2.5 ohm resistor in series, and installed a mini toggle switch under the motorman's door.  These lights are incredibly bright and they don't have that bluish hue that "white" LED's have.  For more details on this circuit, click bright headlights. 15.  For the rear lights (red LED's), I found I could use the original Aristo LED's and wire it the same way I did the headlights.  With bright headlights in front and red taillights in back, it looks great.

Improving running:

Several people have reported that swapping the trucks such that the rigid axle is towards the center and the floating 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)

the pic processor used for the voltage regulator is a PIC16C620A

Mallet 2-8-8-2

(remember: links to sub-pages at the bottom of this page)

click to jump to the bottom

Overview

This is a great new loco from Aristo. It pulls well and tracks even better than the Mikado, which uses the same motor blocks.I believe this is true due to a single boiler applying weight to 2 articulating trucks. In the Mikado, you have a single long wheelbase that rocks fore and aft on poor track.

Be sure to consider improving the power pickup, it made a lot of difference on my loco.(even though the design theoretically has pickup on all drive wheels, you may find this is not working, see the "Prime Mover Basics" page.)

The QSI install is pretty easy, but you need to add another wire between the loco and the tender to run sound, or you can do what I did, and put the sound in the boiler, much more realistic.

It is very easy to take apart to get to the wiring, see the disassembly section.

Since it has the "new" gearboxes, it has the propensity to have drivers come loose and the chance of destroying the valve train components and sometimes even the gearboxes, so you need to check the tightness of the drivers on the axles periodically. This is a common and documented problem. If you follow my tips in the Prime Mover Basics page, you can make this a very reliable drivetrain if you take the time and effort.

Sub-Pages

Click the links below to go "deeper" into details on the Aristo-Craft 2-8-8-2 Mallet