American Models RS-3, FM Trainmaster & Baldwin
TMCC compatible conversions

Re-purposing Electric RR Co.'s Mini Commander with Custom Software.
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American Models RS-3 narrow hood and drive towers presents a challenge to convert to TMCC.
The Electric RR Co.'s Mini Commander TMCC board is a slick fit. 
A custom made heat sink for the HC-1 and HC-2 triacs also serves as the mount for the board. The heat sink must be isolated from the chassis. 

 The Triacs run very cool with the DC can motor. Two external  diodes (1n4004) are used for the motor. One on each HC output. HC-1 is forward and the HC-2 is reverse. The antenna is just piece of solid  wire (orange in the picture).
The Mini is a new product from the Electric RR Co. Designed as a multi purpose unit. It is designed as an Accessory and Switch control unit. I will be using these neat things all over may layout soon. 

The LC-1 an LC- 2 outputs are used for the headlight control.

The Mini's small size (.9 x 1.9") makes it practical to install in most anything. 

This picture shows the 2-56 Triac mounting screw. The HC-2 connector is a close fit but it will clear the screw head.


Here is how the insulator is mounted under the heatsink. The insulator is just a piece of cardboard cut to with a 1/8" hole punched in it and a fold at on end to prevent the heatsink from touching the frame if it is turned.  One could use a piece of silicone heat sink rubber insulator if one has it. A 7/64" hole is drilled through the loco frame and countersunk on the bottom side.  Remove the plastic fuel tank first.   
The Mini straddles the motors drive coupling. 
Here are the parts to mount the Mini.

6-32x1" nylon flathead screw
Cardboard insulator.
2-56x5/16" screw.

The heatsink is made from 1/32 aluminum sheet metal.

The triac screw hole is drilled with a #52 drills and tapped 2-56 through both holes.

The heatsink base is drilled for a 6-32 tap.

The Software used in this Mini is a custom written version.
Here is one of my American Models  FM Trainmaster Engines with the Mini Commander conversion too. The red wire is the added external antenna
A little more room in the FM Trainmaster than the RS-3 but it still needs the small size of the Mini to do a TMCC conversion. I have a pair of these also that will run in a MU lashup
The American Model's Baldwin Switcher presented more of a challenge to fit in the limited space of the Baldwin's chassis. I made a slightly different heatsink mount for the mini in the Baldwin that I used on the RS2 and FM units.  It is shorter and mounts at 90 degrees from the other version heat sinks.
The connectors on the end of the Mini were removed and the motor diodes were soldered directly on the board where the HC-1 and HC-2 connectors were. The other connections for power and headlight were also soldered directly to the board .
The red wire is the antenna. I removed the Mini's onboard antenna
This unit also has the low speed gearing offered by American Models. It really can crawl a drag through the yards.